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Aluminator Gibtec Build

448K views 789 replies 65 participants last post by  eschaider 
#1 · (Edited)
Thread update: Table of Contents

Since this thread has gotten long and I've received many PM's on Facebook and e-mail with questions about the build, I figured a ToC would help anyone searching. It is based on 15 posts per page, and is also broken down in groups and now with hyperlinked post numbers. In the event some quick info is needed, this should make it easy! Also, all hyperlinks, other than the obvious cut-and-paste links are bold so they stand out and are easier to recognize, especially when not logged in.

p.1 (Posts 1-15): Short block, pistons, heads, '98 Cobra cams, bearings, ARP parts list, oil pump & windage tray
p.2 (Posts 16-30): Oil cooler gasket, block heater, head gaskets, more on ARP
p.3 (Posts 31-45): Timing components, cam bolts
p.4 (Posts 46-60): Timing cover bolt modification (aluminum block), upgraded secondary tensioner
p.5 (Posts 61-75): Cam degree tools
p.6 (Posts 76-90): Misc. chat
p.7 (Posts 91-105): Oil slinger discussion
p.8 (Posts 106-120): Oil slinger cont., rear main seal
p.9 (Posts 121-135): Rear main seal cont.
p.10 (Posts 136-150): King bearing tech from Ed
p.11 (Posts 151-165): King bearing tech cont., GT-500 rockers, timing cover hole (Cont. from P.4)
p.12 (Posts 166-180): Degreeing the cams, '98 specs
p.13 (Posts 181-195): Degreeing the cams cont., timing cover, cam follower install
p.14 (Posts 196-210): Primary tensioner ratchet modification
p.15 (Posts 211-225): Primary tensioner spacer modification (update to P.14)
p.16 (Posts 226-240): Primary tensioner spacer modification cont.
p.17 (Posts 241-255): Valve cover mock-up, exhaust manifolds
p.18 (Posts 256-270): Tensioner spacer info from Ed, ready to pull "old" engine
p.19 (Posts 271-285): Oil cooler, PCV fitting for aluminum block
p.20 (Posts 286-300): Quick Seat info
p.21 (Posts 301-315): Old vs. new piston trivia, valve covers
p.22 (Posts 316-330): New engine installed, Centerforce clutch
p.23 (Posts 331-345): Crank damper, accessory belts
p.24 (Posts 346-360): Transmission install, accessory belts cont.
p.25 (Posts 361-375): Power steering pump and A/C install notes
p.26 (Posts 376-390): First start!
p.27 (Posts 391-405): First start cont.
p.28 (Posts 406-420): Notes on PTW clearances from Ed, Vampire introduction
p.29 (Posts 421-435): Rod clearance notes from Ed, block bore information
p.30 (Posts 436-450): OE piston trivia
p.31 (Posts 451-465): Misc. oil pan discussion
p.32 (Posts 466-480): Head stud info & torque notes from Ed, wideband install, PCM harness info
p.33 (Posts 481-495): PCM connector notes
p.34 (Posts 496-510): Gauge install, oil pressure sensor, billet oil filter
p.35 (Posts 511-525): Oil and pump discussion
p.36 (Posts 526-540): Head stud re-torque
p.37 (Posts 541-555): Head stud re-torque cont.
p.38 (Posts 556-570): Head stud re-torque cont.
p.39 (Posts 571-585): Project cost sheet, Vampire install completion
p.40 (Posts 586-600): Vampire adjustments
p.41 (Posts 601-615): AFR and piston notes from Ed, Vampire gauge addition
p.42 (Posts 616-630): More from Ed on detonation, new CAI
p.43 (Posts 631-645): Vampire gauge video clip
p.44 (Posts 646-660): Dyno tune results and video clip (11/1/16), new oil separator
p.45 (Posts 661-675): Switch to Mobil1 0W-40 & UOA, piston wrist pin discussion, updated alternator
p.46 (Posts 676-690): General alternator discussion
p.47 (Posts 691-705): Bolt torque & #5 thrust bearing comments, upgraded tensioner, Whipple 2.3 on the way
p.48 (Posts 706-720): Whipple talk, new intercooler, more fuel system chat
p.49 (Posts 721-735): More on the Vampire, 4.6 vs Coyote discussion, intercooler pictures
p.50 (Posts 736-750): Eaton removed, intercooler comparison pics, Whipple installed, intercooler tech
p.51 (Posts 751-765): Some e85 talk, first drive with the Whipple and new intercooler
p.52 (Posts 766-780): Visit to Gibtec, some info on Prolong
p.53 (Posts 781-): More on Prolong, new Explorer ST to go with the Cobra.

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This project had been in the works for a while: started a few years back when I picked up a brand new set of FRPP heads and a like-new Aluminator block for less than $2,000, which sat in storage until now. The smart thing to do would have been to sell the goods and make some money, especially since my OEM engine only has 21,000 miles on it, but who can resist tinkering. Adding to that, when you can make something leaps and bounds better, might as well enjoy the fruits of your labor while you have the chance.

I'll actually begin with a shot of where I am as of the date I decided to start this thread (fall of '15), but will go backwards to the early stages and update it little by little with as much tech as I can. Since there are not a lot of Aluminator builds out there, hopefully this will be helpful to anyone considering this route. Here's the long block:

Automotive tire Motor vehicle Automotive design Automotive exterior Engineering


Before moving on, I have to pass on a world of thanks to Ed for designing the finest 2618 aluminum piston out there through Gibtec of Denver, and for his willingness to help out so many on this forum with the encyclopedia of knowledge he possesses!! For those that haven't seen the Gibtec "Custom ModMotor Piston" thread, here are my specs (0.002" oversize) and pics added from it:



Gas Circle Plastic Electric blue Liquid


Camera lens Camera Camera accessory Digital camera Lens


Helmet Sports equipment Automotive lighting Sports gear Audio equipment


I also intended to add an Aluminator build page up on my own site, but for now it just serves as a link back here since this got long. For anyone curious about the Aluminator block, this Castings page has a bunch of information on what makes it such a great choice! Stay tuned, more to come...
 
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#695 ·
I have a question regarding the flanged #5 upper main bearing ( king F5219U). I see one oil port on the bearing which i assume is for a an iron block compare to 2 oil port for aluminum block. Any modification done to the bearing to use it in aluminum block or is it OK use it like that ?
 
#696 ·
The 5219 #5 upper thrust is intended for use in Aluminum blocks as is. The rest of the main set should be 5281SI bearings. The 5281 bearings will come with dual oil feed holes. The 5219 upper thrust will come grooved with a single oil feed centered on the oil feed in the bearing saddle.

The 5219 #5 upper thrust will not work in Romeo blocks and perhaps other iron blocks. The 5219 #5 upper thrust is intended for use in Aluminum blocks as is.

Ed
 
#698 ·
You can add additional oil feeds if you wish. It is not necessary.

The additional feed hole to provide thrust face oiling while a nice idea, is not necessary if your trans shop builds your transmission correctly. If they do not build it correctly, even the additional oil feed will not be capable of sustaining the thrust face long term.

If you want to drill the #5 upper and block, the hole is at 12 O'Clock and centered on the thrust face of the bearing. While you can go bigger, a 0.125" hole is adequate.

Ed
 
#699 · (Edited)
Just when I figured this thread was officially complete, I wanted to tinker once again and add another item that was something I meant to get on this summer: an upgraded supercharger belt tensioner. When Jeff was tuning it, he had me watching the OE tensioner as it flexed and moved at high RPM's, and suggested a better one and/or a shorter belt (the 74.5" belt is already about as snug as it can be, so I'd have a real hard time with a 74").

In any case, an easy "upgrade" here would have been the Metco support plate, but I decided to go with the bang-for-the-buck and picked up a new tensioner made by Roush, their p/n 404225. I ordered it up through American Muscle, and with a discount code, it was just under $130. Since the Roush facility isn't too far away (where it was drop-shipped from), I had it in my hands in less than two days.

Credit for this actually goes to former Roush employee Dan Watts who used his own engine as the test mule to make sure this could be adapted to the 4V 4.6. For those who know Dan, he was the one selling all those Roush-ported DC heads a few years back, and is a racer himself. While I'm not making the same high boost as him, I figured a little more tinkering would be fine, especially since this new tensioner is such an improvement over the stock part. This picture from Dan shows it mocked up:

Motor vehicle Automotive tire Hood Automotive design Automotive exterior


Here it is next to the OE tensioner (a new spare I had) - it's a monster to say the least:

Bicycle part Font Gadget Audio equipment Rim


Automotive tire Camera accessory Bicycle part Tire Auto part


Unfortunately, it was not a direct bolt-in. You have to swap the pulley once it arrives (it is spec'd for the '05-'10 3V engines and comes with a non-grooved pulley), and then it needs to be shimmed slightly to line up. I needed to move it forward just about 3.5mm, but that wasn't a big deal. Once you set it next to the original version, you can see how the pulley height is mis-matched (although not at the best angle in this picture):

Automotive tire Nickel Coin Currency Gas


In any case, once I figured out the distance I needed, I was able to put together pairs of 8mm washes that were actually about 3.4mm thick and set them in behind the mounting pads. Dan mentioned that studs would make this easier (for sure), and although I found companies online where I could acquire aluminum spacers, I didn't want to buy a large quantity and then have to wait. Here's how it set up for me:

Automotive tire Automotive exhaust Rim Bicycle part Cylinder


Looks great from a bit farther back (lifted the s/c coolant tank out of the way to make this easier):

Automotive tire Black Motor vehicle Rim Automotive fuel system


Overall, if you want to skip out on the higher price tag of a billet tensioner and want to stay with the OE look, this is a great option. I probably could have survived without it, but definitely wanted to see what it would take to fit, and then pass the info along for anyone else that may be interested.

Updated section on my own site as well:

Idlers & tensioner

Just too bad the driving season in NE Ohio is winding down...
 
#700 ·
Nice upgrade, Joe. The price and Roush name certainly makes it an easy choice.

What I am waiting to see is the twin screw upgrade. I understand those Whipples can remove several hundred pounds off the front tires, particularly at wide open throttle ... :)


Ed
 
#701 · (Edited)
Nice upgrade, Joe. The price and Roush name certainly makes it an easy choice.

What I am waiting to see is the twin screw upgrade. I understand those Whipples can remove several hundred pounds off the front tires, particularly at wide open throttle ... :)

Ed
That could definitely be on the horizon, Ed: a 2.3 Whipple with the 3.25" pulley would be perfect. It's still a blast to drive now, but...
 
#703 · (Edited)
When the car was on the dyno last year, I was watching the original tensioner moving and flexing as the RPM's went up. At some points, the belt was slipping and even though the boost was maxing out around 14psi, there were occasional drops down to lower levels. Not a huge ordeal, but it did add some hiccups.

I could have survived without this, especially for just street driving, but wanted another project just to see if I could make it fit. Since it's stronger than the OE piece and looks somewhat stock, I'm happy to have it. If anyone else is interested in an upgraded tensioner and doesn't want an expensive billet part, this lets them know there is another option.
 
#705 ·
My, My, My!:salut:...What a nice looking little air compressor we have there. :angel:

I am confident, at WOT, that will take a couple hundred pounds off the front end :smart:...:grin:

Now, let's see. Little pulley on the top, big pulley ...

Ed
 
#707 · (Edited)
Not going to get too crazy, just up to 15PSI for now. Will just keep on using 93, and if necessary can toss in some Torco:)

While I'm at it, have to give a shout out to Mark at Lightning Force Performance for the great deal here. I ended up also buying a black SBTB from him so it would match the Whipple housing nicely and the whole package was about $3,300 shipped (I do have one of his SBTB's already, but it's polished aluminum and has always performed flawlessly, so it will get sold along with the Accufab plenum). Even better, the 3.25" pulley will be standard rather than having to purchase it separately to replace the stock 3.5", which saved me another $160. For the cost, they are definitely a great bang-for-the-buck compared to some of the other ones out there.

Generic TB pics for the heck of it:

Material property Camera accessory Automotive lighting Eyewear Cameras & optics


On that note, I was searching for a compressor map of the blower and found a PDF on this site that Ed had posted, so I took a screen shot and added to it slightly as a comparison to the Eaton blower (my pulleys compared to "stock"). Since the 3.25" pulley equates to 15PSI, it's easy to see the efficiency of the Twin-Screw over the Roots. Since I believe the Whipple compressor has its roots (for lack of a better word) in Lysholm, I think this is accurate:

Rectangle Slope Triangle Plot Font


Compared to the Eaton, which for me was topping out about 13PSI, and just outside of its "sweet spot" with about the most boost I wanted to put through it (from my Engine page that will be getting plenty of updates soon):



Just from using a blower speed of 12,000 RPM, the Thermal Efficiency can be plotted at 63%ish with the TS, and only around 50% with the Roots at the "top" P.R.'s (assuming boost is constant), or at least that is how I read these charts when comparing them. Will be doing some more digging to kick up my knowledge on the Twin-Screw's, but had listed this document on my site as well from KB on the difference between the TS & Roots that is good reading: http://www.terminator-cobra.com/KB-twinscrew-vs-roots.pdf

Another good article from Ford NXT (and probably a lot more out there on the web): http://www.fordnxt.com/tech-stories...perchargers-101-heres-the-whipple-difference/

Definitely looking forward to the temperature drop and the increased efficiency, and will be patiently waiting until early next year before I can do some driving again. For those of us looking forward to higher education on these blowers, I know Ed will chime in at some point to share some of his expertise!
 
#708 ·
Actually the articles by KB and Ford NXT are very good. As usual KB does a yeoman's job of covering the technology and translating it into simple English words for the rest of us. The Ford NXT article is also excellent although, occasionally, editorial license cut some of Dustin's comments a little short.

While increasing compressor swept volume is a long standing favorite metric for blower selection, where Whipple is going with the lobe contours of the rotors is the foremost area for improving compressor efficiency. Twin screw compressors are about 100 years old today. Alf Lysholm developed the design after reviewing German Patents for the German Krigar compressor design.

The different purposes for Lysholm's and everyone else's screw compressors quickly sorted down to three distinctly different rotor designs. One design was for oil-free compression (this is the design we know and love). The other two designs were for oil-flooded air and refrigeration compression.

White Organ Organism Font Parallel


The original two lobe design on the right was the German Krigar solution and produced 1.5 psi of boost with a predictably very low noise level. The blower was well suited to the environment / purpose of the original design. Lysholm on the other hand saw a bit farther and produced his first three lobe version which is the drawing on the left.

The original compressors had a lobe design somewhat reminiscent of a traditional roots design as the image below illustrates;

Nose Hair Head Hairstyle Eye


Later as Lysholm was improving the basic design he settled on the rotor contours that are so familiar to us today and are illustrated below;

Head Eye Human body Organism Gesture


The difference between the Lysholm design and all the other compressors / pump designs was sort of the difference between bow and arrow weapons and an M-16. Similar usage but one is much more effective. The challenge in the pre CNC era was a manufacturing challenge. The rotor shape was complex to put it politely.

There is an excellent article on Alf Lysholm that I borrowed the pic from over here => Alf Lysholm.

The basic design that Lysholm conceived today with computer modeling, CFD analysis and sophisticated multi-axis CNC milling machines is coming into a design renaissance. I have attached a research paper on the approaches being used today to push the leading edge of the Lysholm compressor efficiency threshold out even farther than it is now. The technique uses sophisticated remodeling of the rotor shapes and other things.

Right now I need to go to dinner with the Wife so this is it for now but more to come.

Ed

p.s. It is not light reading but its is excellent reading and it is not really that tough or long. Definitely worth a twice over :beerchug:
 

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#709 · (Edited)
Good stuff as usual, Ed. Thanks! Lots of info out there on the web for sure.

These showed up today to take the place of the standard Whipple badges and my order confirmation went in as well, so it's getting pretty official. Perfect time for another winter project, right behind the new axles.



For any Whipple owner that wants the FRPP emblems that used to come on those kits (although they are updated from the image shown on their site with the new ones being much nicer):

https://whipplesuperchargers.com/index.php?dispatch=products.view&product_id=69

Also, for the Whipple fans, their very nice receptionist sent me the FR instruction manual to put on my site: a great addition if you are a fanatic about records and documentation:

http://www.terminator-cobra.com/Whipple FR installation manual.pdf
 
#710 · (Edited)
No progress right now with the cold settled in, but the big box from Whipple should be here sometime in the next couple of weeks...

I did also speak with Jeff @ CRT about my tune, and he pulled up my data logs while I was on the phone. The long and short is that he does not see me needing a new tune. He did hint that I may want to get on the dyno at some point just to see the changes and have him look everything over just in case, so that will be a possibility in the spring.

His comments about my tune essentially were centered on two areas: MAF counts and FPDC. I don't recall the number he gave me for MAF counts (maybe 800-ish?), but he stated I had "plenty of room" there. The FPDC was only about 65% (thanks to the BAP), so he again reiterated that I should have no issues at all, but just to keep an eye on the AFR once I am back on the road. Sounds good to me.

Otherwise, with this upgrade all being new, I decided to add one more piece just so I could stash away another obsolete OEM part: the intercooler. Although mine is fine, and there are plenty of used ones on the market, I ordered a new one from LFP so I could put everything together in short order. I'll still sell my ported Eaton, but I can take my time getting that all cleaned up and will stash the Garrett intercooler for safe keeping.

Here's a pic of the LFP unit, which is made by Griffin (originally their CS-000AE-45, now just AE-45 through LFP). The SVT logo is just advertising and not actually painted on, by the way:



I don't expect any huge differences with this, but figured it would be convenient to try, especially since Mark gave me about 25% off. Even better, it actually cost me $0.00 after cashing in some annual rewards points on one of my credit cards. For some useless trivia, this is a 10-row unit compared to the 9-row OE/Garrett version, and is actually about 1/2" shorter and wider than stock. Apparently they are known to drop the intake temperature about 10°F, but we'll see.

For convenience, I picked up new gaskets for the EGR, IAC, intake manifold, and the coolant inlet by FelPro through Advance Auto (only about $30 shipped). For anyone needing them, they are easy enough to look up, but here are the part numbers just to save some digging:

IAC: 71216
EGR: 70149
Intake: MS 96110
Coolant inlet: 73051

Last but not least, if you are yanking your supercharger, it's always a good idea to pick up a spare set of the coolant tube o-rings. I didn't check the size of them through commercial sources (may look that up later), but the Ford p/n is N802927-S. They come two to a pack:



Hopefully it won't be too long until I update again with some new engine bay pictures, but since it's crazy cold here in OH, it will still be a few months until I get to have any fun...
 
#713 ·
His comments about my tune essentially were centered on two areas: MAF counts and FPDC. I don't recall the number he gave me for MAF counts (maybe 800-ish?), but he stated I had "plenty of room" there. The FPDC was only about 65% (thanks to the BAP), so he again reiterated that I should have no issues at all, but just to keep an eye on the AFR once I am back on the road.
You do have plenty of room with your MAF counts (max is 1024) and FPDC but If I were you I would also keep a close eye on Injector DC. If you have a short coming on any of those 3 you are gonna be building another motor.

--Joe
 
#712 ·
Unfortunately, I won't be able to do a direct apples-to-apples comparison since this intercooler will go right on the Whipple. In any case, when the time comes, I'll be happy to note what I see. Even if there really is no difference, I'll still be glad to stash away the OE part and have this in there.
 
#714 ·
Good tip, thanks. I'll double-check on that (which he may have mentioned as well), but I'll go out on a limb and assume that if there is plenty of room on the other two, the third will be fine. With the 60's and BAP, I'd have to imagine I won't be short on fuel at all. In any case, I'll start off with some easy driving to be sure!
 
#715 · (Edited)
Joe, I am using the fuel system calculator to see where you are size-wise on the injectors. This is an example of a 2.3 Whipple with a 3.5" upper and a stock lower with the useable engine speed set to 7500 rpm;

Rectangle Font Material property Parallel Screenshot


I set the local altitude for sea level with a max engine speed of 7500 rpm to quickly give you a sense of where you are. When you go to page 2 you see this;

Rectangle Font Slope Parallel Screenshot


This screen tells you a lot about the fuel system. The fuel being modeled here is E10 gasoline with a SpGr of 0.755 and a stoichiometric point of 14.08. The fuel pump duty cycle is set to 85% and the AFR is 11.20:1 which correlates to 0.8 lambda. I would not go any leaner than this. Just to be conservative I would consider using 11.0 or 11.1 for my target AFR.

The illustrated engine wants 604 cc (57.5 lb/hr) injectors, if your fuel system base pressure is 43.5 psi (3BAR). If your fuel system base pressure is set to Ford specs (a better idea), the 3BAR injector size required is 60.6 lbs/hr - which within a cats whisker is where you are right now. If you go above 12 psi of boost you should consider going to larger injectors, i.e. the 80 lb/hr Siemans-Deka units.

BTW your engine wants 246 lph of fuel at 7500 rpm which means you are beyond the performance capabilities of a single 255 lph pump. Your engine will require two 255 lph pumps which, if I remember correctly, is what you are using.

Pilots are trained to do a lot of things to protect our bacon when we are flying as passengers. One of the things you are trained to do is less bacon sensitive and more equipment performance sensitive. There is a magical metric pilots use that I believe is called altitude density. If my memory is still somewhat intact I recall that commercial jet aircraft pilots use that to find (among other things) a small performance window where the plane can be flown with a reduced drag and just below the speed of sound. If I try to fly faster, the plane does not like it and tells me about it by starting to misbehave. If I fly slower while still stable I use more fuel. If I got that correct, it is quite a balancing act.

Fueling our engines is a similar sort of balancing act. However, instead of balancing fuel economy and aircraft stability we are balancing power output and engine longevity. That 0.8 lambda (11.2 AFR) red line is the important threshold to stay on the correct side of for power output and engine longevity.

Ed
 
#716 ·
Good info, Ed - thanks. Not sure why, but it never dawned on me to plug the values in on my own - although it's most likely since Jeff squashed any uneasiness I may have had about the current tune. Might play with it later at some point for sure.

On a fuel note, I still have the OE 119LPH pumps with the BAP, which can be pumped up to about 378LPH according to KB (injectors are 60's as well). With the FDPC at only 65% or so, I'm hoping I don't have to mess with any of that. Still, I'll probably just granny-drive it a couple times when the weather gets nice, then get on his dyno at the first opportunity to see if he needs to make any adjustments. No sense in putting any of my hard work in jeopardy.

Don't confuse me too much on all the density-altitude stuff when it comes to the flying: we're spoiled by all the automation taking care of the calculations;) At least if we get too close to any limits, the computers will start making some racket, but nothing like using experience to stay out of trouble. Now if I could ever just grasp all the car tuning mysteries - that's the harder subject in my book!

P.S. Jeff does also tune in Lambda, so the 0.8 number sounds familiar as well since I think that was his target from the start.
 
#717 · (Edited)
The 0.8 lambda target is one that the more experienced tuners frequently end up migrating to for both reliability and performance.

Just for grins I ran your engine configuration with a 65% duty cycle and targeted for ~60 lb injectors to see where it would sort out. Here is what the calculator second page looks like;

Rectangle Font Screenshot Parallel Number


Running E10 (SpGr 0.755) you can hit a 65% duty cycle on the 60 lb injectors and still maintain an 11.2 AFR (0.8λ). To do that however, when you check page 1 of the calculator, you will need to keep the engine speed below 6000 rpm.

Rectangle Font Material property Parallel Screenshot


Without changing injectors you can go as high as 7500 rpm and still get the 60 lb injectors to work. The difference is that the injector duty cycle needs to increase to get the required fuel to the engine. This is a Calculator Page 2 for 7500 rpm and 60 lb injectors,

Rectangle Font Parallel Screenshot Number


Although you are getting higher up the injector duty cycle ramp (81% in this case) you are still well below 85% and certainly safe. As you increase the air either by running higher in the rpm or upping the blower overdrive (or both) the Ford ECU will compensate by increasing injector duty cycle for additional fuel until the injector is tapped out. As a good rule of thumb you want to be at an 85% duty cycle or less at maximum engine speed and WOT

The primary consideration, safety not withstanding, is that you have left yourself very little headroom for growth. Even something like a top or bottom pulley change (depending on how large the change) can put you over the top for the fuel demand the engine requires at 7500 rpm - which is the origin of my suggestion about the 80 lb Siemans Deka units.

Most importantly, right now, you are more than safe. Additionally, the KB Boost-a-Pump will provide you good service quite a ways up the fuel demand curve. KB's BAPs work exceptionally well.

BTW I always thought pilots considered instrumentation advisory in nature - just kidding :)

Ed
 
#718 ·
I love that this thread keeps humming along. It's always been great reading.

Anyway, I am in no way a tuning master, but I have been messing with the SCT PRP since 2005, and I have managed to keep my stock short block together. I wanted to chime in on this to lay out my thoughts, and hopefully hear your thoughts on choosing an air to fuel ratio target. The first thing I want to mention is lambda, and the old school, non-ethanol gas numbers.

If you're like me, you grew up referencing air to fuel ratios based off non-ethanol gasoline with a stoich of 14.7. You have also probably looked at many dyno graphs with "safe" air to fuel ratios of 11.8 to 1 (Gas: 14.7*.8=11.76) and sort of bought into it as the standard. An 11.8 air to fuel is certainly okay, but I don't believe it to be very conservative at all. At 11.9, you're getting in the danger zone, and 12:1 (stock 03 cobra commanded lambda .82) is really pushing your luck, as you've essentially run yourself out of wiggle room in high horsepower/low octane applications.

If you're running 93 octane from the pump today, you'll want to be aware that you're probably running e10. E10 has a stoich point of 14.1(ish). .8 Lambda will give you an 11.28 (E10: 14.1*.8=11.28) air to fuel ratio which seems quite safe, but it's essentially no more rich than 11.76 on non-ethanol 93. The only safety you gain is what you gain from the ethanol. I don't know how much knock suppression you get from it, but it's probably not a whole lot.

Another thing to keep in mind is data collection. Most of us use one or two wideband o2 sensors to base our tunes off of, but if you think about it, we're only getting an average of one or two banks when we look at our data. We have to assume that our cylinders are not exactly the same, so there will be some sort of combination of lean/rich/optimal cylinders in that bank which average out to our measured lambda that we log and make our adjustments off of. If you're looking for .8 lambda at the o2 sensor, it is entirely possible to have a hole that's at .75 and another at .83.

There are solutions for this, and you'll either need to get your hands dirty, open up your checkbook, or throw a bunch of fuel at it. The easiest thing to do is to throw fuel at it. I ran for years at a 10.3 air to fuel ratio (.73 lambda on e10) just to make sure I don't have a lean hole. You can also read your spark plugs. If you read the plugs and find you have a lean cylinder(s), the factory ECU does not have the capability to do much about it. If memory serves, you can have it pull timing globally for an individual cylinder, but I would have to have verify that. An aftermarket ecu provides you with the tools necessary to make any adjustments necessary to tighten up any differences in the cylinders.

After all that yapping, I would recommend setting the air to fuel ratio in the .75 lambda range on gas, and creep up towards .8 by reading the plugs.
 
#719 · (Edited)
I wouldn't disagree with your guidance one bit, Josh. The 0.8λ is as lean as you want to go and you are right about the bank of cylinders being able to hide a lean hole hear and there behind the 'average' for the four on that bank.

BTW for those who get unlucky enough to have the one bad apple hiding in the average for a given bank you will experience incipient detonation, that usually will not hurt the engine in a once or twice sort of occurrence. The problem is you can't hear this type of detonation and it occurs continuously. The piston in the pic below, if I remember correctly, is Jeff's (Edmisten). Jeff had his engine 'professionally' tuned a number of years ago and his tune had incipient detonation because of a too lean lambda / AFR. Here is what the piston looked like a few years down the road;



Obviously wounded but, as Jeff will tell you there were no outward signs the damage was so bad. FWIW Jeff also primarily drove his car as an attitude adjustment street vehicle not as a race car. Race car operation would most likely have failed the pistons. If I remember correctly it was not just one piston that was wounded, I believe it was all eight or nearly so. The tune was (at the time it was done) believed to be conservative.

<Edit> Joe already has a J&S Vampire. The following encouragement is for those who do not <Edit>

Supercharged gas engines are among the most detonation sensitive engines. If you do not have one I highly recommend a J&S Vampire for detonation detection and correction. Nothing else can do the detection and correction job except the J&S product. BTW it is important that you both install it correctly and also calibrate it correctly. Both can be a bit of a PITA but if you buy one and do not do that, it begs the question why did you spend the $600 or so for the J&S. Improperly installed and / or improperly calibrated for your engine it is exactly the same as not having it. The only difference is your wallet is lighter by about $600 plus whatever parts you inadvertently hurt

Parting thought, while none of this stuff is inexpensive, individual cylinder EGT sensors at least used during the tuning phase, help you identify potential problems by highlighting a change in EGTs hole to hole. This is by no means a 100% test because of sensor response times but it is a darn sight better than being EGT blind. While you can use EGT sensors with both OEM and aftermarket EFI systems the integration into and value you will receive in the aftermarket version EFI systems is decidedly better.

Thanks for elaborating Josh. Your commentary was spot on.

Ed
 
#720 ·
Yep that's outta my OEM engine. That was hole #7 and the worst one. The other 7 pistons were marginally better. That was about 10 years and 30K miles. And yes a crappy tune, the factory .82 lambda with a KB 2.2 @ 17-18 lbs on pump 93. It didn't self destruct or anything. Just got to where it wouldn't idle when it was cold until there was a little heat in the engine and the constant tick where that piston was hitting the bottom of the head. Good times...and lesson learned.
 
#721 · (Edited)
If you do not have one I highly recommend a J&S Vampire for detonation detection and correction. Nothing else can do the detection and correction job except the J&S product. BTW it is important that you both install it correctly and also calibrate it correctly. Both can be a bit of a PITA but if you buy one and do not do that, it begs the question why did you spend the $600 or so for the J&S. Improperly installed and / or improperly calibrated for your engine it is exactly the same as not having it. The only difference is your wallet is lighter by about $600 plus whatever parts you inadvertently hurt
I became a full supporter of the J&S system within minutes after the first test drive (registered knock at 6-7psi of boost on 91oct before the meth was activated) and now I try my best to open the eyes of people who are glad to spend thousands of dollars on go-fast parts but not one penny on protecting their investment. Gent's, I'll say this again: If you're running pump gas get this knock detector system. It can detect the knock while it's happening in each cylinder and actually DO something about it AND tells you about it while it's happening.

People defend themselves when they don't have it by saying "the plugs don't show detonation so I don't need one". But detonation may not show on plugs plus the detonation has already happened before you even check the plugs...not good.

I have spent a lot of $$ on electronics to protect my investment and it's a great piece of mind having them monitoring the engine.

My car is set up as a flex fuel car so it runs on E85 and 91oct/meth but I still have a J&S Vampire monitoring for knock and a Lean Protection Module that monitors the A/F.

If I can digress: The dyno operator was leaning the tune out in order to get the turbos to spool quicker on E85 but after about 15 minutes of fighting issues he asked me if I had something installed that would shut the engine down if it got too lean. I told him, YES! ...he just laughed..

ks
 
#722 ·
Your experience echos that of the other guys who, like you, made the decision to use a Vampire, Kevin.

Like Kevin said we spend extraordinary amounts of money on these engines to produce power. The next step to protect our investment should be an easy decision but invariably it becomes among the toughest calls we have to make. That could be because of all the money already spent and our suspicion that another $600 or so may not make a real difference so why "throw away" the money or perhaps the many less capable protection systems out there today.

For all those who are reading this thread, nothing could be a better use of your hard earned monies than one of these Vampires. Kevin's first hand experience is identical to other users. An old member (Smokin'04) with a turbocharged engine like Kevin's had his tuner in the car street tuning the engine. The tuner had accidentally put too much timing into the timing map for first tune attempt. When Garry (Smokin'04) stood on it the Vampire lit up like a Christmas Tree and the car fell on its nose! The Vampire had caught the mistake and saved the engine! Garry was running either 10:1 or 10.5:1 compression on pump gas.

Kevin, Josh, Joe, Garry and the other site members who use this system will tell you, if you ask and frequently even if you don't ask, the Vampire really does exactly what J&S tells you it does. You need to take the time to properly install it and calibrate it and it will provide you a protection against detonation that simply is not available with or from any other product today. It is far and away the best and most important $600 purchase you can make for your engine.

Ed
 
#723 ·
awesome post Kevin, I have indeed been playing with fire but trusting my tuner. I will be getting a J&S setup soon. After my current round of winter mods this will be my next major purchase!
 
#724 ·
My tuner loves having it on my car. When tuning on gas/meth he holds the knock gauge right next to his eye while watching the dyno screen and when he sees a single LED light up on the gauge indicating KR he lets out of the throttle. This tells him exactly at what RPM the knock is occurring so he can make adjustments at that exact point in the tune. Great tuning aid.

ks
 
#726 ·
Glad to have kept this thread going with my ongoing tinkering! It also makes me feel better knowing certain things, like the tuning, are left to the pro's, especially since I was fortunate to find a good guy (more props to Jeff @CRT). Adding to that, it's obvious that John's Vampire also gets plenty of credit for being worth it's weight in gold, so it's also been a pleasure to keep spreading the word.

Now I actually may have wrapped this thread up a bit sooner had I just pulled the trigger on the Whipple in the first place. In the back of my mind, I was somewhat dreading the process of the head stud re-torque, so having the Eaton blower still on there did make it a whole lot easier. In any case, I have seen the Twin-Screw light and can't wait for the next bump. With all of Ed's info from the fuel calc's, I can see a dyno run happening as soon as the weather gets warmer here (although that seems like a long way off with as cold as it's been), so I won't in any way cut corners after all this work - and writing.

So still waiting on the big boxes, and will add the obligatory pics and updates soon, and even when this is actually "finished", I'll still hope this is all going to continue being great reference for any engine builders out there. Thanks to all of those who have chimed in and enjoy the reading!
 
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