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Are you interested in a completely upgraded IRS sytem / group purchase?

  • Yes I am interested

    Votes: 103 56.3%
  • No I am not interested

    Votes: 11 6.0%
  • I am interested but would like more information before committing

    Votes: 69 37.7%
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Discussion Starter · #1 ·
I have been communicating all weekend with Frank Rehak, the owner of Drive Shaft Shop.

I've directed him to our board and shown him the posts and issues with our half shafts and the few instances of broken replacement units.

Here are some of the emails he has sent me recently:

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rich
thaks for your interest in our products, the system we now offer is a center bar upgrade. we have sold about 45 sets and have no faluires. the center bar is made from 300M the strongest material you can make an axle out of, if you send in your axles i will change over the c.v.'s to the new (300M) bars and do a special de-stress to the factory parts for added strenght and we will also use symthetic grease and high durometer boots to finish it off.

p.s. we will be making a complete set of axles with 300M ends in the very near future cost will be about 1400.00 for the set. i would wait on the group purchase for these extreme units, aprox due date is mid november

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hey
i just went on the board to see what was going on, you know i can make a custom hub for the car with a larger c.v. with no problem. do the cobra's run the 5x4.5 patter ? i have a extremely large c.v. to fit balnks for this system already and with a sample could be produced rather quick. let me know we live for this stuff

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rich
thanks for the info, you are a good collector of information.

give me a few days to do some research (i have a set at the office currently from Mustang magic) if you could get one of the broken units i would be very interested in sending it out for a quantum analysis to see what the factory made them from, you see with this info and taking the tire size,torque and rear ratio we can spec the parts out to be over-developed to not only handle the power but give it cycle life.

the fact is if the axle breaks your stuck we have made allot of c.v. axle problems disappear in the sport compact market, this would be a good challenge for our abilities.

our last challenge was to keep axles in a Turbo MR2 (i know its an import but read) the car weighs about 3000lb and the cars have been getting from 400HP to 800HP low 1.4 60 ft times and yea you guessed it broken axles, we have done about 35 set so far for them and now the cars are getting air in the front and not thinking about axles any more. i believe we can do the same for the mustang crowd. being a old hot rod guy myself i promise a
solution to this problem.

Frank Rehak

President/CEO
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Here's a link to the type of kit that Frank is proposing:

http://www.driveshaftshop.com/item17973.ctlg

Now, if there is enough interest then we can get DSS to develop a bullet proof IRS sytem for us. And, with a quantity group discount, we can get the price down very substantially.

Everyone, please post your thoughts, comments, complaints and questions right here on the subject. Frank will be silently watching the thread develop and answering questions, addressing concerns either directly or indirectly.

Imagine an IRS sytem that you could put a slick on, come out real hard and not worry about while running sub 1.50 short times. IMO, it's worth its weight in gold!

From what we have seen, only a completely reinforced system, including hubs, CVs and axles will do the trick. It's expensive, but no more than swapping over to a new and reinfoced 8.8 live axle system. And we keep that which makes the Cobra famous.

Everyone, GET INVOLVED in this one!!
 

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Very interesting. By the end of the 04 run, there will be around 50,000 IRS equipped Cobras on the streets. 99's had the 28 spline halfshaft/diff though.

What I'd like to see is a full trade in program. Buy a bolt in- beefed up IRS on a skid. Iron diff, new halfshafts, new hubs, delrin bushings in the cradle bushings, and MM's poly busshings at the frame, with spherical bearings optional at the frame. Swap over your brakes, then drop the stock IRS on the skid and ship it back as a core.

But with shipping costs, that's probably not going to happen.

Anyway to help with offset of the stock wheels/315 tire combos with a custom hub as well?
 

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What's wrong with the MR-2 Turbo!? Built mine to 332 RWHP. Anyways, I am here as an interested party...
 

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Hammer, as we discussed on the phone, I'm in.

I feel strongly that bigger is the way to go. Higher strength steel is all well and good, but I really think bigger components AND better steel is needed.

While higher grade steel obviously has advantages, certain characteristics are fairly constant, mainly the modulus of elastisicty. I belive the current high strength units are smaller diameter shafts with better steel. While they may have higher ultimate and yield strength, they probably actually deflect more, and when the flex. They need to flex back, adding stress through the driveline.

These larger units seem to address these needs. The only issue I see is how big an the outboard stub shaft and mating hub spline be made and still have the outboard bearing fit through the existing spindle.

As bad as a broken halfshaft is, the thought of changing one out doesn't bother me near as much as one of my wheels coming off on a 3-4 flat shift. If the outboard stub shaft can be made strong enough, I believe this will be the answer we have been looking for.
 

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I would buy this in a heartbeat.

It's just a matter of time before another halfshaft breaks. I've made up my mind the next time, a solid axle will go in, but that's not what I want at all.

Will the new design decrease wheel hop?
Someone mentioned adjusting the hub for wheel offset...another good idea so we can finally run wider tires without jumping through hoops.

Hey Frank....I bought a set of your halfshafts last spring. They're holding up so far! Thanks for a good product.
 

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Sounds like a great idea to me. The kits that only replace the shafts without the cv joints are worthless.

Paul S.
 

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I love my IRS and don't want any of the problems already experienced to make me want to part with it in the future. Lots of good ideas here to make the whole package better. I would spend the money for something that gave me piece of mind... whether at the track or on the road. Especially with future mods I have in mind. :D
 

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Replacement IRS System

Need-4-Speed has a GKN Heavy Duty Halfshaft Kit for $900. How do these compare to the other upgrade units aviable??

AMB
 

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I'd definitly be interested!!! Souds very promising, maybe this can solve all my wheel hop issues! I'm IN! Who wants to hook up with me so we can rob a bank??? :evil
 

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Yes, I'm very interested.

A fellow Cobra owner went to Infineon Raceway (Sears Point), for the first time, got some wheel hop and snapped his half shaft last week. Ford says no warranty since he was racing.

I have yet to visit the track and would love to know that my little beast would not break when I did make the trip.
 

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Sounds like you guys have finally found someone who may be able to make some parts to fix the IRS weak points. I certainly hope so. Here are my thoughts.

The axle or intermediate shaft made out of 300M is a good addition to a street tire or even a drag radial car. But a car capable of sub 1.8 sec 60' needs stronger CVJoints and outboard stub shafts.

I would concentrate on the outboard stub shaft first, then the inboard stub shaft, after upgrading the axle or bar and the CV joints.

I wish you guys luck. Let me know if I can be of any help. My car was the test mule for the GKN halfshafts. I put a live axle in early in 2002.

Joe Lynch
 

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Discussion Starter · #13 ·
Joe Lynch said:
The axle or intermediate shaft made out of 300M is a good addition to a street tire or even a drag radial car. But a car capable of sub 1.8 sec 60' needs stronger CVJoints and outboard stub shafts.

I would concentrate on the outboard stub shaft first, then the inboard stub shaft, after upgrading the axle or bar and the CV joints.
Joe, I wanna be clear on something. Are you saying that the 300M center bar upgrade will be too weak for sub 1.80 short times...or are you saying that it's a good strong component, but requires the rest of the components as a full system in order to be strong and reliable?

I wanna be clear on that. Isn't 300M the strongest material that axles can be made of? At least that is what I've been lead to believe but I want your uncensored input.

Thanks for the input, Joe!
 

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The 300M material is what GKN used. I broke two. It is a good material, but the strength of the bar is limited by the diameter of the splines which are inserted into the stock CV joints. When the CV joints are redesigned, the bar diameter at the splines can be increased and the bar strength improved. That is why I am hoping the CV joints can be made larger.

Keep in mind that the ABS rings must fit the inner CV joint and the outboard joint must clear the lower control arm, etc.

Keep in mind that by making one piece stronger, you move the failure spot somewhere else. You DO NOT want the weak spot to be the outboard stub shaft!! Without strengthening that piece, which requires new hubs and possibly a spindle, you are limited as to what improvements are possible.

Joe
 

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Keep in mind that by making one piece stronger, you move the failure spot somewhere else. You DO NOT want the weak spot to be the outboard stub shaft!! Without strengthening that piece, which requires new hubs and possibly a spindle, you are limited as to what improvements are possible.
At what point would the differential case and/or rear cover become the weak spot? Specifically the areas they are bolted on to the IRS?
 

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Something will definately need to be done to address controlling the rotation of the center section.

I have some ideas, but the potential solutions look complicated. I guess we will cross that bridge when we get to it:)

JT
 

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JT said:
Something will definately need to be done to address controlling the rotation of the center section.

I have some ideas, but the potential solutions look complicated. I guess we will cross that bridge when we get to it:)

JT
Hey JT,

After grenading two sets of poly carrier bushings, I'm going to machine a set of bushings, front AND REAR out of Delrin or glass-impregnated nylon. This should cure rotation of the center section. I'm also going to be fabricating an IRS housing brace based loosely on Mr. Lynch's design (he was kind enough to send me his to use as a template). This should take care of the cover problem. Ideally we could get a vendor to fabricate a custom billet cover, but I'm not going to hold my breath on that.

I've been running the DSS halfshafts and have about 50-60 passes on them with no problems. Most 60's have been in the low-mid 1.7 range. I even cut a 1.695 which is awesome for me! Although I would love to have the reliability of the live-axle for the strip, it's just not where I want to go with the car.

MJ
 

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I also was wondering about maching some bushings but out of uhmw, we at work here have had much sucess using this material a little less hard than delrin/acetal or nylon but practically unbreakable.
 

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mjchip said:
Hey JT,

After grenading two sets of poly carrier bushings, I'm going to machine a set of bushings, front AND REAR out of Delrin or glass-impregnated nylon. This should cure rotation of the center section. I'm also going to be fabricating an IRS housing brace based loosely on Mr. Lynch's design (he was kind enough to send me his to use as a template). This should take care of the cover problem. Ideally we could get a vendor to fabricate a custom billet cover, but I'm not going to hold my breath on that.

I've been running the DSS halfshafts and have about 50-60 passes on them with no problems. Most 60's have been in the low-mid 1.7 range. I even cut a 1.695 which is awesome for me! Although I would love to have the reliability of the live-axle for the strip, it's just not where I want to go with the car.

MJ
mj,
you should check with john mihovitz @ accufab, about making the billet rear end covers and possibly a billet case for the 03 cobra's. john already makes billet rear end covers for the live axle 8.8 rears. if there was a demand for these 03 cobra parts, he would probably make these parts too.
 
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