How much horsepower?

S8n · Post by **S8n** » Wed Sep 21, 2005 8:16 pm

I am in the beginning stages of swapping an LS1 into my '87GT 5-speed. The car is going to be a street car for the most part, but will see a few trips to the track. I'm trying to figure out, from the experience here, how much HP I need to run low 12s, high 11s. Stock, my motor puts out 320ish at the crank,with a cam it can go as high as 425. When I had my '02 Z28, I was runing 13.4 with 3400 lbs of car with just an intake. Now with only 2600-2700 lbs., how much more power do you think I will need? If you know it, could you post your times and horsepower figures? Oh, and yes I know I'll break a few things along the way. :thumbleft:

crzyone · Post by **crzyone** » Wed Sep 21, 2005 9:32 pm

A stock LS1 with a good driver might be good enough for low 12s.

Will has run a 12.8 with a 275hp chip on his N*

A cam in an LS1 should put it in the high 11s, doesn't take much with a light weight mid engine car.

Now you have to think about investing in trani's, the LS1 has quite a bit of torque.

S8n · Post by **S8n** » Wed Sep 21, 2005 9:41 pm

That's my next issue. Is the tranny the weakest link? Or will something else usually break first? Either way, I hope to make at least one pass before things start to break.

crzyone · Post by **crzyone** » Wed Sep 21, 2005 9:52 pm

Most people seem to break the trani first. After california kid had his trans cryotreated, he has been breaking cv joints I believe, his trani has held up pretty good.

Not sure how much power he is making, I think he claims around 400hp at the flywheel.

Shaun41178(2) · Post by **Shaun41178(2)** » Wed Sep 21, 2005 9:54 pm

having the hp and actually getting to those low e.ts are two different animals. For one you will have to drive the hell out of your car with an stock LS1 to get into the 12's. Yea the power is there but if you bog the launch or spin too much or shift slow, poor track conditions will all effect your E.T.

To get low Et's you need a good launch. Since you are using the 5 spd I would be hesitant of really nailing off the line. I would roll into it and shift slow. Yea your ets will be higher but your trap speed will still be good. A bone stock Ls1 will prob trap close to 110 in a Fiero. Et's will vary greatly.

To run 11's you will prob need close to 450 at the crank. Your tranny won't last long with that much power.

S8n · Post by **S8n** » Wed Sep 21, 2005 10:12 pm

Looks like I have to find a way to strengthen the tranny then. Anyone sell aftermarket internals? I've rebuild kits, but they seem to use stock parts. I figured when actually laching this car, it would be easier to drie it out of the hole instead of dropping the clutch. I got a lot of experience "driving it out of the hole" with my Lightning. The torque will be the culprit. Anyone have any other HP numbers and stuff they broke?

crzyone · Post by **crzyone** » Thu Sep 22, 2005 1:43 am

I've been in a 406 sbc fiero with 430whp with a getrag 5 speed. Lets just say first 3 gears were all rubber and could powerslide at will. Most insane thing I've ever been in. Probibly over 500lb/ft as well, I was AMAZED the getrag could take the power for a second. I was impressed.

Some tranis fail with the stock 6cyl. Just make sure the transmission is fresh, and if you are worried, have the gears cryo treated as well.

Kohburn · Post by **Kohburn** » Thu Sep 22, 2005 8:01 am

crzyone wrote:I've been in a 406 sbc fiero with 430whp with a getrag 5 speed. Lets just say first 3 gears were all rubber and could powerslide at will. Most insane thing I've ever been in. Probibly over 500lb/ft as well, I was AMAZED the getrag could take the power for a second. I was impressed.

Some tranis fail with the stock 6cyl. Just make sure the transmission is fresh, and if you are worried, have the gears cryo treated as well.

its always safest to have the tires be the weakest link - saves the tranny -
unfortunately it makes the car a handful to drive

p8ntman442 · Post by **p8ntman442** » Thu Sep 22, 2005 12:45 pm

If you want to build a tranny to last, I suggest a 3.61 getrag 5spd out of a nbody early 90's. Tear it down, replace the bearings, check the synchros, and then send the whole gear set to get shot peened and cryotreated. The bead blasting will remove imperfections from the gears that cause fractures and uneven wear. A limited slip unit from engineered performance (wait till that deal gets sorted out to buy from them) may help in reducing the forces on your cv shafts.

edit to replace bead blast with shot peened.

crzyone · Post by **crzyone** » Thu Sep 22, 2005 2:53 pm

Kohburn wrote:
its always safest to have the tires be the weakest link - saves the tranny -
unfortunately it makes the car a handful to drive

Thats the thing, he was running 265's in the rear. This is Troy Ritchie, the same guy with the 383 on nitrous that can run 10s. He doesn't do anything half assed. Its just an amazing car.

Kohburn · Post by **Kohburn** » Thu Sep 22, 2005 3:17 pm

crzyone wrote:
Kohburn wrote:
its always safest to have the tires be the weakest link - saves the tranny -
unfortunately it makes the car a handful to drive
Thats the thing, he was running 265's in the rear. This is Troy Ritchie, the same guy with the 383 on nitrous that can run 10s. He doesn't do anything half assed. Its just an amazing car.

thats a little more impressive.. I still want to make strut adaptors for the rears to allow the 335's or whatever the size was that the yellow pontiac sd4 drag car ran

S8n · Post by **S8n** » Thu Sep 22, 2005 6:49 pm

Yeah, the tires are going to be the weakest link (hopefully). What's a N-body and will it bolt and mount right up? Or do I stick the internals into my case? Am I going to find a company locally to bead blast and cryo or is there a reputable one out there that you know of? Sorry for all the questions, I just want a car that I don't have to work on every weekend. Once a month is fine.

fIEROWISEGUY · Post by **fIEROWISEGUY** » Thu Sep 22, 2005 8:48 pm

Actually "bead blasting" usually refers to glass beads, great for cleaning metal of paint and rust.

What you want is SHOT PEENING. And it does exactly what you describe. It also work hardens or toughens the metal surface, too.

Results are often fantastic. I have seen the fatigue life of springs increase from 25% to 400%. The size of the beads, the velocity, and time are all important factors to see this kind of improvement. Find a place that does it, and TALK TO THEIR METALURGIST. Tell him what you are trying to do and he'll do it right.

By the way, this is just what you should do to connecting rods, too. Just polish the sides of the rods before you have it done. It's well worth the money.

p8ntman442 · Post by **p8ntman442** » Thu Sep 22, 2005 9:55 pm

an n-body is the platform name for grand ams, calais, achievas, sklarks, aleros, malibus etc. like the fiero is a p-body, the luminas grand prixs are w-bodies, the corvette is the y-body and last but not least the camaro and firebird are the f-body which is most commonly known. the n-body transmissions can be either izuzu or muncie-getrag. rodneydicman.com sells the adaptors to use the fwd tranies in a fiero.

S8n · Post by **S8n** » Thu Sep 22, 2005 9:57 pm

Good info! Here is the two places I found on google:
http://www.cryogenicsofindiana.com/
http://www.cryoplus.com/index.html
Any experience with either?
So here is the question: What do you do first, shot peen or cryo treat? They recommend treating the entire transmission, not just the gears.

Post by **eHoward** » Thu Sep 22, 2005 10:01 pm

I would do the case if you're doing the gears.

p8ntman442 · Post by **p8ntman442** » Thu Sep 22, 2005 11:13 pm

any machining and or shot peening should be done b4 cryotreating. 300below is a good place as well as north west cryo.

cryo is the last process, all other work should be done b4 hand. They do it by lb, so the case might as well get the treatment.

TurboGT · Post by **TurboGT** » Fri Sep 23, 2005 1:23 am

How much should you expect to pay to get the gears and case peened and cryoed?

S8n · Post by **S8n** » Fri Sep 23, 2005 4:02 pm

p8ntman442 wrote:any machining and or shot peening should be done b4 cryotreating. 300below is a good place as well as north west cryo.

cryo is the last process, all other work should be done b4 hand. They do it by lb, so the case might as well get the treatment.

That's what I was looking for. Thanks for the info! Do either of those places have web sites that you know of? And lastly, should the case get shot peened? I think the first step I'll take is ti magnaflux the gears to make sure none are cracked already...

The Dark Side of Will · Sun Sep 25, 2005 11:10 pm

Shaun41178(2) wrote:having the hp and actually getting to those low e.ts are two different animals. For one you will have to drive the hell out of your car with an stock LS1 to get into the 12's. Yea the power is there but if you bog the launch or spin too much or shift slow, poor track conditions will all effect your E.T.

To get low Et's you need a good launch. Since you are using the 5 spd I would be hesitant of really nailing off the line. I would roll into it and shift slow. Yea your ets will be higher but your trap speed will still be good. A bone stock Ls1 will prob trap close to 110 in a Fiero. Et's will vary greatly.

To run 11's you will prob need close to 450 at the crank. Your tranny won't last long with that much power.

Real World data:
I cracked 12's with 250 rwhp and 1.9 sixty foot.
FieroX cracked 11's with 325 rwhp and 1.5-1.6 sixty.
Figure 350-360 to crack 11's with more reasonable 1.8-1.9 sixty.
At those power levels, loss through a 282 is going to be less than 10%. That means it should be possible with less than 400 crank HP.

Cryo treatment is not to be undertaken lightly. It is a heat treating process. It is the continuation of the quench phase of the factory heat treating process. As such, it will cause dimensional changes in the material. To do it right, you need to final grind the teeth after you have the gears cryo treated, in order to maintain maximum tooth contact area. This will increase your backlash, of course.

Real Fiero Tech

How much horsepower?

How much horsepower?

Bead blasting.