Pjduto

Hi all. Looking for input on my C-5. I bought the car from a dealer and it appears to be heavily modified. The dealer advised the person who he got the car from told him that when he purchased it 5 years ago, the motor had just been rebuilt. It has a vararam intake with K&N filter. The dealer advised the gentleman he got it from stated the car had ported heads and intake, upgraded cam, long tube headers and magnaflow exhaust. It also has an aftermarket balancer which is smaller that the stock one. He claimed the car was making around 500 rwhp. Does this sound possible? I would think 400 rwhp is reasonable. 500 seems high. I am unable to contact the owner who did the work. Thanks for any input.

redzg

500? How does it idle? 500 is an awful lot.

road pilot

Possible but unlikely.

c4cruiser

Do you know if there has been a tune installed along with the other mods? You can certainly add HP and torque just by installing a tune.

Is there a shop nearby that has a dyno? That would tell you right away what the actual power levels are at the rear wheels. Around here, you typically can get 3 pulls for around $75.00.

knewblewkorvette

Welcome to the forum
500 rwhp is ALLOT for a NA LS1. It can be done though.
I agree with c4crusier, find a dyno nearby and see what she does.

Dirty Dog

Find a dyno or a drag strip and eliminate the guessing...

500 from a NA LS1 is a lot. Possible, but a lot. It would be more likely if the engine were stroked with heads/cam/intake/exhaust.

Vetteman Jack

Yeah, 500 rwhp without forced induction is pretty high. I don’t see that happening with the mods you have. It was a good suggestion to find a local dyno and make a few pulls to see how the car does.

Have you tried asking the dealer to contact the previous owner and see if he would mind if you talked to him about the car? Worth a shot if you haven’t done that.

Patches

Maybe 500 crank hp . . .

zeevette

I had 483 RW with custom Trickflow heads and a 228-232 cam, and a FAST 90, plus other minor mods.

Pjduto

The idle is not smooth but not as rough as I'd think would be present for the cam profile required for 500. The dealer bought the car from an owner after the mods were done. He was who the dealer contacted to get the information I presented in the original thread. I don't have the ability to contact the owner who did the mods. The vararam long tubes and magnaflow are visible. I found out the hard way the balancer was replaced trying to get the right belt... The idle is rough enough to indicate the cam. I can tell you it walked a C-6 pretty bad. I am going to a car show tomorrow at Muscle Car City. I'll have to inquire around about dyno availability in the area and will update after I can get my runs in. Thanks

grantv

Can you see a casting number on the heads? Might lend a clue. Standing on passenger side of car, front right of head is where the factory heads have their number.

Pjduto

The heads are still 71's, but the dealer advised they had been ported during the rebuild. I am unable to verify that although a quick visual inspection appears to indicate they were removed at some point. Way too clean for 14 years old at edges. However that doesn't prove porting.