power limits?

[dark knight]

how many have done all the mods', and are at the "400hp" level? and if so, what parts give up first/regularly? i'm thinking of buying a 1g awd, and modding to the 400 hp level. i'm reading of tranny,transfer case, front/rear diff' problems. i don't see any reason in trying to put 400 hp to the ground through a fwd.if i don't do bonzai 6k launches will the tranny, t case, diff's hold up? any/all info is appreciated. i've tried searching through old threads for help, but don't see any clear answers. thanks to all.

 

[turbo4wd]

I can touch on this a little bit. At, my guess about 350HP I lost my center diff to wheel hop. After I fixed that I lost my ACT2600 (20k miles and lots of launches by slipping it) At about 375HP I spun a rod bearing. I know of a few others that stripped teath off gears at 400HP levels. In all honestly, it really depends on how bad you beat on the car. I am sure there are guys out there that run 400HP all day long and don't break anything. Then there are the other guys, that want to run on the edge and push their cars at that level too. They are the ones that will break things. Example: if I didn't shoot for a low 1.7 60ft I would still have my stock center diff. If I didn't race a new C5 vett to 165 mph I would still have my stock bottom end. Instead I have a Quaife Center Diff and an Extreme Race Short block... -shawn

 

[Canada Kid]

Hey Shawn. Curious. How much did you spend and what did you do to go 12.58? Just trying to get an idea.

 

[dark knight]

thanks for the info turbo4wd. that helps me get an idea what/when will happen if i get to the 400hp level. does the t.c. viscous eliminator, or welding the stock piece reduce the chance of t.c. failure, or is it just a band-aid? and with the eliminator/welded piece how does it effect around town/every day driving? thanks again, keep the info coming.

 

[turbo4wd]

Canada Kid,
Hmmm Did a post and it never went through... I am actually embarrassed about the time. With what I have in the car I should be be either very very very low 12's or high high 11's. So far I am finding that ever time out to the track I am braking something on the car. I think the other thing holding me back is the weight of the car. I weighed it as 3460 lbs with me in it. I am so jealous of people who say they got the weight of their car under 3000.
Also something to keep in mind - I ran a 12.79 @ 106.5 with a small 16g and 550's on the car. Put a larger turbo, injectors and stand alone in the car and only did a best of 12.58 @ 110.9

 

[turbo4wd]

Dark Knight,
I am not the best tranny guy and there are probably others out there that can answer better then me. If you weld the center diff you are locking the front and rear wheels together. When you weld the VC I think it does something similar. For a street car I would not recommend it. Next time the tranny is out of the car crack it open and put in a 4 spider or you can spend some big $$$ and put in Quaife or Kazz Center.

 

[97EclipseGSX]

Originally posted by turbo4wd
I think the other thing holding me back is the weight of the car. I weighed it as 3460 lbs with me in it. I am so jealous of people who say they got the weight of their car under 3000.

Damn now you're making me jealous. I'm sitting at 3300 on the dot, with me in it. I've never seen a 2G in street trim that weighed under 3000. I want to be there too. : )

I figure I can drop 60 with the rims that I'm going to purchase (that is if the stock rims weight 30 pounds like I was told) and if I remove the rear seats I could get it to about 3230 or so. I'm still jealous. : ) What else can be done? I remove the jack tools, rear cover carpeting and deck, spare and front right head light when I race. I guess I could get a carbon fiber hood but I've never seen one that fits perfect. Anyone know who makes a quality one thats pretty light?

 

[DSMotorsport]

Welding the center diff is sorta overkill for a street car. Both BM and SPeeddesign make 4 gear cetner diff's that will hold up to high 10's. the stock VC are a little weak, but ususally they just stop "limmiting slip" and fail to where they allow too much wheelspin. It's not anything that's going to make the car undrivaable if it fails.

I put a welded diff in my shop's "racecar", after breaking the stock center diff. I paid BR $300 to weld it since i wanted it done right, and it has to stand up to 1.50 60's.

The 3 bolt rear axles will break consistently with low 1.7 60 times. 4 bolt rears will hold low 1.6's easily. I broke my first 4 bolt axle two weekends ago (same pass the diff broke). If the axle/diff didn't break, I think the 60' wouldhave been a low 1.5. This is on 4 225 drag radials.

The front diff is AFAIK bulletproof, and you shouldn't have to worry about it at all.

the rear diff itself is also pretty much out of the question..you won't break that

Driveshaft....VERY VERY VERY rare to do any damage there.

Tranny....i have heard of some people having actual gear problems, but again...rare.


Xcae output shaft breaks sometimes...ususally on 10 sec and faster cars.

 

[thedsmsource]

I hae built a few transmissions already and have found that most transmissions hold up fairly well as long as you use common sence. My daily drivers tranny has 180k+ on NO rebuild and still drives fine. The big thing to do it to replaces shifter forks, rails, and upgrade the center diff. These are the usualy parts that break, and their metal fragemtns destroy the rest of the transmission. And the most important is common sence, when driving the car on the road shift nice and slow, and don't abuse it. You need to either race on the track, or drive normaly. Slamming through gears on the road isn't nessary, and your tranmission will be happier if you do. Save it for race day.