paladineWS6

Hi guys first time owning an ls1. Happy to join ls1tech.com . My mames oliver and recently bought a trans am 3 months ago for 5k dollars. Its a silver ws6 but I suspect it to be a clone. The car was disgustingly slow when I bought it. I bought it cause it was cheap with an ls6 intake, lid, 243 heads, hooker headers, slp loudmouth exhaust, and torquer v2 cam. Well it took me 3 months but I got it tuned by dan maslic and had all the lil things wrong with it like alignment and ac fixed. Now my problem, the car is making 281 to the wheels in hp and torque. Dan told me the exhaust is restricted and I know its prolly the budget resonator I put in because of the noise of the exhaust im thinking of replacing the resonator with the slp one it came with. Dan said if I make the exhaust more free flowing ill get 10 to 20 more whp .... so 300 whp max? I thought an ls1 with these mods would make more any help sorry for grammer im typing this on a slow android phone!! Thank you guys

The car is a 1999 pontiac trans am "ws6" with 82k miles I got it with 79k it is an m6 with the ls1 engine, and the mods on my previous post I had a pontiac bonneville sle before this with a top swapped l36 engine to compare my bonneville felt much quicker than this trans am

RPM WS6

iTrader: (3)

Stock they usually make between 280-310rwhp, but some have gone even higher. Cars optioned with SLP dual/dual and Blackwing air lids are technically still stock, but you can expect them to make more power than the stock base models (equal to aftermarket lid/catback cars).

So you are basically at the low end of stock horsepower, but with bolt-ons plus heads/cam. Something is very, very wrong - and it's not the resonator (unless it's a 1" in/out pipe or something). If an exhaust restriction was to blame, it would be one hell of a restriction to cost you this much power (you are down by over 100rwhp IMO).

How did A/F look on the dyno? Anybody ever check fuel pressure? What about codes (SES light), misfires and such? How is the clutch (slipping perhaps)? That combo has a ton more in it once you get the issue(s) sorted out.

paladineWS6

I have the dyno sheets in the car feom what dan said the a/f looked good but what was happening was that the hp and torque arch down at around 5k rpm so if I got the restriction checked id get 10 to 20 hp lol but thats not the problem he said fuels getting to the engine good and from what he saw the engine should be making close to 400 at the crank but the numbers were so low the only thing he saw wrong was that the alternator stops working after load so maybe it needs a battery or maybe the belt is slipping other than that I dont think theres anything wrong with it

The clutch doesn't slip and it had 2 codes ill check them when they come out again because of the tune I guess the codes were wiped

RPM WS6

iTrader: (3)

There is definitely something very wrong. You shouldn't just be at 400 crank horsepower, you should be in the 400 rear-wheel horsepower range.

You are down by WAY more than just 10-20hp at the wheels. It would take a massive exhaust restriction to account for the ~100rwhp that you're missing.

Take a look in the Dyno section of this site. You'll see the typical numbers for heads/cam/bolt-on M6 LS1s. Either your engine is significantly down on power, or power to the wheels is being lost by a slipping clutch under WOT.

300rwhp should not be considered acceptable for this setup.

That is my experienced advice and opinion. Hard to know what the problem might be with the details given so far. If there are codes, it would be good to start with that.

paladineWS6

P0121 I know I have other codes but only thos one is showing up atm

I am going to take a picture of the dyno results but I dont know if itll help

What common things could cause so much power loss? Maybe it isnt cammed and the guy that sold it was lying about the cam?

HCI2000SS

iTrader: (2)

Well you should be able to tell if it is cammed or not lol. Do you have any video clips of the car?

paladineWS6

Ill make a quick one im at work atm

http://m.youtube.com/watch?feature=y...e_gdata_player

RPM WS6

iTrader: (3)

That's a throttle position sensor code. Something may be wrong with that sensor or wiring.

If there are other codes, you'll want to list them as well.

The video didn't work. Even if you have a stock cam, the 243 heads plus all the bolt-ons should still have you at a much higher power level. Your current number is at the low end of the stock spectrum.

Several things could be the case here. How does the engine run/idle otherwise? Ever done a compression or leakdown test on this engine? If the clutch is stock then I still suspect that there might be slippage.

If it's losing power above 5k rpm, perhaps the valve springs are weak, and are floating.

ragtopz28

iTrader: (57)

If it's losing power above 5k rpm, perhaps the valve springs are weak, and are floating.[/QUOTE]

^^That was going to by my guess

paladineWS6

Well today while he was tuning it at the higher rpms it blew a large plume of black smoke through the exhaust maybe it was unburned fuel?

Lets see this link? Quick walk around for ls1 tech - YouTube I really wanna figure this out if it means gainning 100whp heck even 60 or 50 whp I wanna figure it out so it might be the valve springs? I checked the clutch by going 70 and then putting it in 5th and flooring the car and it immediately accelerated without a hitch ao im guessing the clutch is good also the phone doesnt really record the sound well but it does sound cammed maybe if I record from father away? Ill recheck the codes tonight omw home but I know that 0121 code and if I recall a skip shift code are the only ones that come out maybe a 3rd code

Yes the car has antifreeze its topped off I check it every 3 days the sensor just died last weei

HCI2000SS

iTrader: (2)

Well that definitely sounds like a cam to me.

paladineWS6

So the p0121 could just be my low voltage problem (battery?) Or the cam which is the obvious culprit for the code so the other thing im thinking is compression or transmission? I know my differential needs a new seal or gasket cause it have a pretty good leak but I dont think that would cause this problem

RPM WS6

iTrader: (3)

Yeah I would agree that you definitely have a non-stock cam, based on that video.

P0121 is a TPS code, I don't see how the cam would have anything to do with that.

A differential leak has nothing to do with the power loss.

If fuel pressure is adequate, A/F looks good on the dyno, spark is strong (no excessive misfires or fouled plugs), the tune (timing, etc.) is solid, and the clutch isn't slipping, then I'd look next at valve springs and compression.

paladineWS6

Perfect thanks ill get a compression check if it helps when I put the padal to the floor it takez a while to accelerate its not a sudden violent acceleration like my bonneville

ridiqls

Yeah could be compression loss?
how did u get that far for $5k?? maybe it has a problem like low compression for the price