So my friend lost his diff and has to replace. I am thinking of doing the same. I was getting serious about a solid rear but decided against that. So between the cobra 8.8 and upgrading the stock with TII, Kaaz, race axels etc.. whats the best route?

 

The cost comes out to be about the same either way you go or maybe the 8.8 is a little more.

There are pros and cons to each.

KAAZ
Cost about $800. Axles are about $550 and are stock replacements. If you want the fancy ones, you pay about $1800-$2000 just for the axles. (Ernie and I went this route)

Pros - very simple swap, no downtime involved, anyone can do it, don't need a lift etc

Cons - limited gear ratios, must get a brace of some sort (not T brace) to protect the case from flexing. If using older clutch plates, you may hear noise.


Cobra 8.8
You need to buy a subframe that costs about $600 or so. (SpeedNYC and Turbo R1 went this route) I believe the new subframe needs to be welded in areas so you need a lift and access to a welder.
You will need to get a new driveshaft made. ($300 give or take)
The PPF is no longer needed but now you need to make a brace for the tranny which easy.

Pros - Gearsets are cheap and you have a ton of options. Very strong. Will not hear any noise.

Cons - Much more difficult install. In the end may cost a bit more. Harder to go back to stock if you wanted too (if selling car etc) You have to buy a used cobra rear, you can get lucky or get a bad rear.

I'm sure SpeedNYC, Enzo can add to this since they went this route.

Anthony

 

Good info Anthony!

 

Yeah, thanks for the info.

 

I have a Kaaz and 300m axles. I launch at 8.5k without preloading. I usually cut mid 1.5 60's. It was very easy to install and took only a few hours. I paid around 1k for the whole setup.

 

Are you using any brace on the diff?

What tires are running?

 

Waaachback, also what kind of tires are you doing those launches on.

 

Also what about your suspension setup? This is what I am trying to find out and see if there is any connection. Your axels and lsd wont save your diff case..

 

No diff brace, however, I do have solid poly diff mounts.

26x11.5 Et Streets at 10-12psi.

Stock shocks, RSR coil-overs dropped about 2 inches.

 

Driveshaft shop axle/hub upgrade/ Kazz/ diff girdle/ upgraded diff bushings/trailing arm-toe link upgrade/ Koni adj. shocks/ eibach springs. 26x11.5x15 ET street
1.40' 60's all day

 

So upgraded diff bushings will make a big difference? The setup you listed seems very doable (for me) and wouldn't deviate much from the stock suspension appearance.

 

Doable yes, but $$ .... axle $1500+, Kazz $800, diff brace $350 + the rest.. So you are well over 2k and getting close to 3k.
Gotta pay to play..

 

Not sure if they made any difference. I bought them cause when I had the kazz put in it had to be taken out and anything was better than 16 year old rubber bushings...lol...

 

They did for me. The rear feels much more stable with them. There is also less clunk.

 

Currently I have solid diff bushings and a diff brace but Im having massive wheel hop issues. My next step is upgraded toe and trailing arms and if that stops the prob then start thinking about a shock and spring combo. Hopefully I can start pulling off some decent 60 times like the rest of you guys.

 

Well, I was thinking on the lower end of the cost... 300M axles, T2 LSD, new diff case and brace, trailing arm/toe links, and adjustable shocks = less than $2000, I already have Eibachs and upgraded bushings... besides, I'm nowhere near the power level of Ernie, so the downgrade options won't make a difference.

 

Yeah, thats the ticket.. But make sure you get one of Ray's diff braces (girdle).

 

Wow, you're up at 7:30 AM... or have you not went to bed yet?

 

I have kgparts diff brace is the general consensus that these t braces are just for show?
I'll be buying pfs diff cradle do you still use this in conjuction with a diff brace like a kgparts one?
If the kgparts ones are not very good is the Banzai racing one any better?


rgds
Brian

 

They both do different things. The PFS diff brace ties the case together. The KG Parts diff brace helps prevent wheelhop. The reason the rears break is because of flexing of case, the PFS brace prevents that from happening by tieing it together. The pressure on the internal gears put pressure on the case bending it in the middle. Once the case cracks you damage the gears, get ready to get a new case etc....

About 8 years ago Tony from TandR Racing made a brace that prevents wheel hop and ties the rear together. A few guys made their own braces back then but the best deal is PFS since he is only one that sells his.

Skip the banzai brace and just get the PFS brace. A few are using both the PFS brace and the KG parts brace together. Tell Ray you want to use them together and I believe he sells you his with different washers.

Anthony

 

Nice one Anthony, i'll give Ray a shout.


rgds
Brian

 

Are you running slicks? If you are running street tires or drag radials and switch over to slicks, your problems will most likely be gone.

 

got a great deal on couple new viper difs

when my stock torsen diff breaks so far holding up few 1.5s 60' passes with et streets
I am going this route with 4.5 gears

http://www.turbobuicks.com/forums/bu...93-rx-7-a.html

 

This looks like a great way. From the looks of it you don't need to buy a subframe so that save's $600. You use the FD outers with the T2 Inners so there's no cost there either. You'll probably have to upgrade those parts if you start breaking them but this is another good conversion. Thanks for sharing.

 

Yeah I thought of that. But then I might fix one prob and create another as far as extra stress on the drive train and axles. Im slowly trying to address the wheel hop issue and upgrade everything in the rearend one thing at a time before I go on slicks. I dont want to put slicks on break something and be forced to drop a ton of cash all at once (if that makes sense).