Twin Turbo build questions

**turbogiblets** · 01-28-2009, 01:29 PM

A freind of mine is looking into the Hp Twin Turbo kit for his 99 C5. He's looking to make in the 800-900rwhp range. What kind of mods would you guys recommend (motor, manual trans, diff.) to hold this kind of power??

Thanks

**turbogiblets** · 02-03-2009, 10:16 PM

ANYONE????

Will a forged short be ok, or do the heads have to be completely done??? Do I order a forged rotating assem?? Is the factory crank good enough and all is needed is rods and pistons??? Any help would be great!

**MYSCZ06** · 02-04-2009, 03:04 AM

I believe it can be done with a fully forged/built 346 (will be stretching that to its limit) heres awrite up on a FI 346 that hit just over 800

http://forums.corvetteforum.com/c5-f...-800-rwhp.html

best source of info on this build would be over at corvette forum they have guys over there that discuss these type builds daily

**turbogiblets** · 02-04-2009, 07:24 AM

hey thanks for the reply!!! Ithought people were making alot more power with these Ls1's

**NemesisZ06** · 02-04-2009, 11:34 AM

Originally Posted by turbogiblets

hey thanks for the reply!!! Ithought people were making alot more power with these Ls1's

Its usually on a 427 that you are seeing the higher numbers on, not a 346.

**turbogiblets** · 02-04-2009, 08:48 PM

thanks man, I'm new to the LS1 world...Is the factory LS1 crank forged?

**MYSCZ06** · 02-04-2009, 09:10 PM

I have read on here and other boards of some cars holding up to close to 1000hp and have read instances where it let loose with around 600. A quote from this link

Many forged guys including me use the stock crank. It has been used in motors round 800-900 hp. Harlan pushed his to 1000 hp.

link
http://www.ls1.com/forums/showthread.php?t=3622

**turbogiblets** · 02-05-2009, 08:14 AM

thanks for the link...some good info there! I think I'll take my chances with the forged LS1...750-800rwhp is my goal.

**bt-01-vette** · 02-06-2009, 03:04 AM

Originally Posted by turbogiblets

thanks for the link...some good info there! I think I'll take my chances with the forged LS1...750-800rwhp is my goal.

You should be ok, I'm putting dn 768hp 724tq on my forged SC346. Jersey Jay at the Covette Vette Forum just recently sold his TT C5 that put dn closer to the mid 800's with the same motor.

**turbogiblets** · 02-06-2009, 06:31 AM

awesome...good to know. What did you use for heads and intake??

**turbogiblets** · 02-06-2009, 06:33 AM

how much power will the manual trans hold up in a 99 C5??

**bt-01-vette** · 02-06-2009, 01:09 PM

Originally Posted by turbogiblets

awesome...good to know. What did you use for heads and intake??

LS2 heads ported&polished, stock intake. East Coast Supercharging did the work in Cream Ridge, NJ

**qwkgto** · 02-06-2009, 05:00 PM

Originally Posted by turbogiblets

how much power will the manual trans hold up in a 99 C5??

Im betting more power then clutch will.the trans are alot stronger then even most aftermartket clutches.

**qwkgto** · 02-06-2009, 05:06 PM

Originally Posted by turbogiblets

ANYONE????

Will a forged short be ok, or do the heads have to be completely done??? Do I order a forged rotating assem?? Is the factory crank good enough and all is needed is rods and pistons??? Any help would be great!

I can say I know of several guys pushing the envelope on the ls2 I have been running 13-15 and have seen 18psi on mine for over 2 years. My call is build around the motor drive train wont put up with power.tuning is everything.

**turbogiblets** · 02-06-2009, 08:13 PM

tranny is in the rear on the 99 C5...so any shaft or any weak link I should know about...thanks again guys for the info!!

**bt-01-vette** · 02-07-2009, 07:53 PM

You will need the proper clutch that can handle the power or it will be useless. When I did a H/C before the SC it put dn 449hp 412tq and the stock clutch would stick to the floor when shifting when in the throttle. From there I went with a harden output shaft as a precaution, I'm still on the stock tyranny. I don't drag race much (maybe every blue moon) I'm more into road courses so the stock tranny has been fine. Guys that I know that are at or as close to the same power level that I am and that hit the strip often had tranny problems in time. Most upgraded to a RPM Trans with much success. I have a RPM trans support to protect me from wheel hop to keep from braking other drive trane issues. Good luck with you build!