ILLWIN

iTrader: (35)

Just wondering what you guys think would be acceptable rear wheel hp and torque figures for this $25,000 427 cid C5R motor in the 2002 ZL1 Camaro?

C_Williams

Depending on the cam, heads and intake manifold, easily over 500 RWHP & Torque

LOnSLO

iTrader: (15)

Man, those things are meant for driving, not racing. That said, they make good power for the job.

Classic

iTrader: (3)

They make some stout numbers, but remember their numbers are through cats and with a smaller cam (small compared to what most people put in a big cube car). Now, if you threw a BIG cam in - lookout.

restoman45

iTrader: (2)

i saw a dyno graph of one of them at the gm carlisle show, and the dyno graph showed 491/491 to the wheels w/ an open cutout...its a c5r block, ls6 heads and ls6 intake manifold, and a very streetable camshaft(stock 10 bolt rear!?!?, i dont know how it survives) another one i saw i think pulled 483 to the wheels i think, im not sure, but the green one i saw was 491/491 just to let you know

Ron@Vengeance

iTrader: (51)

Glad to see the guys from LWA are inquiring about GMMGs motors. Have Lamar give Matt a call if he has any questions about the 427s....


BTW, since when does using a C5R block make anymore horsepower than a sleeved LS1 block? I dont see the logic in your thought process??!?!?!

I personally have seen several graphs OVER 500/500 THROUGH cats and 18" Cragars

restoman45

iTrader: (2)

where did i say that the c5r block made more hp?...im not a moron, i know a block doesnt make more hp, i just stated that it was a c5r block and not c5r heads, it has ls6 heads(which i dont get why people always call them c5r motors, to me it should have c5r heads to get that designation). the c5r block is stonger than a resleeved block however but in no way does it make more power...also, there were two 427 zl1's down there and neither put up 500 to teh wheels...maybe if their headers were uncapped, but they dyno'd them through open cutous...on a side note, i think they have a reasonably high compression ratio, i think it was 12 to 1, but not positive...

i talked to matt murphy a lot, and i know it has to be a small cam, but w/ a bigger cam, it would make good power...he is a good guy and always anwsered all of my pesky questions, lol

restoman45

iTrader: (2)

oh, small mistake, if i remember correctly, it is an aluminum intake manifold that was designed after the ls6, but is slightly modified...its not a stock ls6 intake, but i could be wrong on that one...

Ron@Vengeance

iTrader: (51)

I dont think I called ya a moron anywhere in my reply. I guess I read into it too much. Looked to me like you were saying because it was a C5R block is should make more power than a sleeved block. You are correct, neither one of the cars in Carlisle made 500rwhp. I can promise ya, 65 out of 69 do

As for the intake, its simply the Holley intake with an engraved plate on it. Cosmetic to say the least.

Ron@Vengeance

iTrader: (51)

and BTW, theres still 2 cats before that "open" cutout, which provides no more power over one of those GMMG catbacks.

DONAIMIAN

iTrader: (18)

QTP found some gain over it using dual cut outs , but what a 5-10 hp when you have 490 more

ls1290

iTrader: (20)

I would say easily over 600 on both rwhp and rwtq for a true C5R setup; block, heads, 14:1 compression, Grand Am cam, and intake that will support the heads.

Assassin

iTrader: (3)

hmmmm $25,000 for a little over 500hp, or a few mods and a 150 shot for less than $3,000......... tough decision....... hey can I have some of those 100 dollar bills you wipe your *** with, j/k

SLowETz

iTrader: (12)

Tough decision??? Dunno....depends. $25k is not chump change(for most of us), but when ol' boy blows by you after you've grenaded your 150 kick stock bottom @ the 60', you may have a slightly better opinion of GMMG's $25k ZL1 motor. You can pay now....or later.

FWIW...I too have personally seen these GMMG bullets make 500rwhp + on a regular basis.

What ^^^ he ^^^ said.....

LOnSLO

iTrader: (15)

Now, if you were to go all out, 600rwhp should be no problem. ESPECIALLY if you work in a machine shop. BTW, how many 500rwhp 427s have you guys built?

robertbartsch

Unless I was competing an a 24 hour race at Lemans in France (Uyk!) I would purchase a C5r block at $6.5K.

...if you want to spend a bunch of money get a Darton sleeved block for $3.5K

robertbartsch

Lingenfelter just RAISED the price for their Darton-sleeved blocks ...2,750 for the block, 250 for hone bore, 600 for core...

Thats 3,600 for the sleeved block!

Vengeance Racing

Hey ILLWIN. You can not win **** especially with a slowass car like you have. Secondly the cars that are being spoken about that only made 491 are true they were the first of the 427s to be built and have extremely small camshafts. Since then we have used bigger cams on about 25 more 427 all of which have made over 500RWHP w/ cats and are very streetable to say the least. You are a local Atlanta guy if you really want to know GMMG uses Dynolab for all testing and tuning go by and look in the book and you will see many dyno sheets all above 500RWHP except cars that have a 4:56 gear which cost about 10-12rwhp on the dyno. Better yet just come by the shop since you seem to know so much about us and I will show you all the dyno sheets on all the cars and you can stop asking questions on the internet. Tell Lamar Matt says HI!

BTW How is GRB car coming???? Does it run yet. Spending alot of time and money on that buildup ey.

Look for a few Solid Roller 427s on a dyno near you from GMMG and I will show ya a big number if that is what you are looking for.

grb

Building the intake for the .090 C5R heads now. Installation will start next week. More Performance (Sept GM High-Tech Performance) may build the intake.

Darkhalf

iTrader: (1)

Just curious I didn't think they put cats on the 02' 427 ZL1's? I thought it was just an ORY with two dual electric cut-outs?
Also I believe all 427 ZL1's come with a 12bolt, correct me if I am wrong.

Either way I hope to find out by August 2nd in LaHarpe, IL