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Thread: Aluminator Gibtec Build
12-12-2017, 04:34 PM #706
Nice! Time to up the boost/timing now and put it on E85 and really enjoy the fruits of your labor ;)
12-14-2017, 04:19 PM #707
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:
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:
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-t...w-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/...le-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!
Last edited by jrgoffin; 01-22-2018 at 10:25 AM.
12-14-2017, 07:49 PM #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.
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;
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;
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.
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
12-18-2017, 04:35 PM #709
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):
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:
Last edited by jrgoffin; 12-20-2017 at 07:05 AM.
12-28-2017, 01:12 PM #710
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:
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...
Last edited by jrgoffin; 01-22-2018 at 11:08 AM.
12-29-2017, 10:18 AM #711
I'd be interested in your results. From what I have read, there were no changes in IAT temps between this and OEM.
12-29-2017, 11:15 AM #712
12-29-2017, 03:03 PM #713
12-29-2017, 04:20 PM #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!
12-29-2017, 05:58 PM #715
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;
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;
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.
Last edited by eschaider; 12-30-2017 at 01:37 PM. Reason: Spelling & Grammar
12-31-2017, 01:01 PM #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.
12-31-2017, 06:09 PM #717
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;
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.
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,
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
Last edited by eschaider; 12-31-2017 at 06:12 PM. Reason: Fixed pic broken link
12-31-2017, 07:09 PM #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.
12-31-2017, 09:07 PM #719
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.
Last edited by eschaider; 01-02-2018 at 12:30 PM. Reason: Spelling & Grammar
01-01-2018, 08:46 PM #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.
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