93 BB Base Half-Bridge GT42R Project PART 2
 

Well I just got back from Winter Park, Fl. That was a fun 4 hour trip. I went up there to pick up this...

https://www.rx7club.com/attachment.p...d=210203&stc=1

It is an 03 Cobra IRS rearend. It only has 20,000 miles on it. I got a really good deal on it too because it has a broken axle and tie rod, but I dont need those parts anyway. Picked it up for $690. It is going in first thing when I get back to STL this May along with my Cobra Cradle made by Jimlab.

I see that most people put 4.33 gears in the rearend but what about even lower gears such as 4.56 or 4.77 gears? What do you guys think?

I am also getting retuned for more boost in Feb. when Steve Kan comes back to STL. Anyway just wanted to show off the new rearend :ky:

nice pick-up....even lower then 4.30 gears...little faster, every little bit helps...
keep us posted later....with the process...

also how much boost you shoting for with the re-tune

brad

Last time Steve tuned my car he was shooting for 26psi but my boost controller was F'd up and would only hold 22psi. It wold spike to 26psi and then fall back down. He said that would put me right at 560-580whp. But this time it will be much colder weather so who knows?

your setup to hold 26psi... injectors and all.....nice... :)
that sucks that the boost controller was the only thing holding you back....
good luck with the tune.... :icon_tup:

brad

This morning I took the parts that I needed out of the subframe. The parts that I need to take back home to STL all fit inside of this plastic container.

So what gears should I put in this thing???

https://www.rx7club.com/attachment.p...d=210365&stc=1

https://www.rx7club.com/attachment.p...d=210366&stc=1

https://www.rx7club.com/attachment.p...d=210367&stc=1

I am going to need a NHRA legal roll cage too. Not sure what to do, either buy a cage or have one custom made..... I would rather have one that bolts in instead of a weld in cage. Any suggestions?

you can have one custom made that bolts in also....just have to ind a good shop arund you....
asking guys at the race track is, how my buddy found his shop...

was wondering what is the advantage to running this setup over a Kaaz diff, chromoly 300M axles, and the diff craddle(not the common diff brace) that Adam, peter farrell, ari ran/runs?

Is this a auto-cross car? If it's a drag car, I hope you know the 03'-04' Cobra IRS (Any IRS really) is known for extreme wheel hop, and that heavy drag strip users go to a live axel.

Read 5.0, or Muscle Mustangs & Fast Fords..

Brilliant black ftw dude. Was tehre any custom work needed to install the Cobra rear-end?

My setup will be much stronger because the Kazz differential still uses the weak cast iron case.....

Its a drag car and the wheel hop will be gone with the proper bushings...

I haven't installed it yet, I just bought the rear end and tore it down......

Try tire size dia., plus trap to run et your going for, the rpm limits and go to gear calculator for 1/4 mile this will give you some idea of gear ratio you will need.

My setup will be much stronger because the Kazz differential still uses the weak cast iron case.....

Thats why you use the craddle that Peter farrell, Adam suwarutari, and Ari uses...
They were cutting 1.3x 60 ft times with the stock case all day long with no failures with over 650 whp, the reason the case breaks is because the pinion pushes back and up and it splits the case right at the pinion...the craddle dissapates the energy all the way to the back of the case, so it wants to lift the whole case up, not just where the power plant frame connects to the nose of the case, which where they usually break and prevents wheel hop damage (which is usually what destroys things anyway)....just seems like a lot of extra work to do and expensive. GOod luck with the install though

Update: Next saturday (24th) I am getting tuned by Steve Kan on C16 and more boost this time. Last time I made 503whp @ 22psi so I hope to break that by a good amount this time.

Also, during the first week in March I am having my roll cage put it. It will be done by Scott at Izzy's Custom Cages in STL, MO. The cage will be a 6 point cage with swing-out door bars. SCCA and NHRA legal for 9.99 ET or slower.

Looks like you're not messing around, Phil! Best of luck with your new setup, and the dyno results :icon_tup:

Looks like you're not messing around, Phil! Best of luck with your new setup, and the dyno results :icon_tup:

6 point is only legal for 10.00 and slower.

That one one-hundreth of a second will get ya everytime ;)

Are you running the "dragon" craddle or a different version, and can it be purchased from anywhere? I've been somewhat trying to locate a craddle version without any luck.

Hey Phil, seems like your putting that Turbo kit to work! Glad to see you turning out the #'s. BTW Phil the stock diff is not weak at all, don't beleive everything you read....... here is a link of Magnus's Rx-7 3 rotor lauching, stock diff with KAZZ and moly axles, no problems ever!
http://www.youtube.com/results?search_query=magnus+rx7

There are only 2 guys running the Cobra diff setup that I am aware of but both are modified from the original Jim Lab setup. Here are the pics, do these two look like yours?

:wallbash: I knew it was right around there. Did any of the track techs say anything to you when you ran that 10.005???

Mine doesn't have those little bushings. I have already bought all of the parts except for the axles, so I am going to go ahead and put it in anyway.... I will prolly have it modded too though, not sure yet. We will see.........

Yes, they tried to kick me out because they claimed to know what the car was capable of. You better be completely legal or don't even think about racing at gateway.

You'll need a 5 point harness that's up to date, firejacket, three inch studs, driveshaft loop, trans scatter shield, properly mounted battery in a sealed moroso etc. box, battery cut off switch, 6 point roll bar with 6X6 mounting plates etc. etc. etc.

That's just to run 10.00 and slower

Damn, I will have everything except for the completely sealed battery box....... :wallbash:

What is Gary legal for???