WTF is going on?

[dethinboots]

The local shops I usually have great success through is throwing something at me I don't understand. I had the Trickflow 550hp top end kit installed after lots of dialogue with the shop. The said the cam and head specs for the install wouldn't pose any problems (225cc heads 238/242 .595 cam) They were excited to get the work done while I was off at airborne school. I come back to a dyno of 439hp (without air filter installed) and less torque. This is barely an improvement over my stock 243 heads and a 224/228 cam. Has the intake manifold been tapped out? He said the injectors weren't working at max and probably aren't the problem. Am I being taken for a ride? Saved for quite awhile to make this happen and am thoroughly disappointed. What's going on?

[pajeff02]

Factoring in a 20% driveline loss, your RWHP would be 440 if you have 550 at the crank. What does your "butt dyno" tell you?

[dethinboots]

I've seen others with a similar setup land around 480. These numbers are only about a 20hp increase over a mild cam and stock heads. Something doesn't seem right. The shop is embarrassed by he numbers and want to talk about possible solutions Monday. Would a higher stall leach more power than a stock one?

[Whamhammer]

I've seen others with a similar setup land around 480. These numbers are only about a 20hp increase over a mild cam and stock heads. Something doesn't seem right. The shop is embarrassed by he numbers and want to talk about possible solutions Monday. Would a higher stall leach more power than a stock one?

Did the shop just bolt on the heads after they got them, or did they have a machine shop check the heads, to make sure that there weren't any wide variances in each port?
I have also heard that the LS2 intake is inferior to the LS6 intake, and because of the construction method the LS2 intake can leak.

Also, was the dyno that ran the test for the old and new runs:

The same

Had atmospheric and temperature conditions included both times?

[0rion]

what did the car dyno with the 224/228? I would expect higher numbers than that out of that cam and those heads.

[dethinboots]

I think they cleaned up the piston tops and block surface but that's about it. It's the very same dyno used for the first cam. The guy also said that it didn't start making good power till around 6500. And even through ls2 intake is inferior I've been told by other shops that going with a FAST or similar product isn't something that's necessary. They successfully run 600hp plus cars with the stocker.

[dethinboots]

The original dyno'd at 418. I have no idea how 225cc heads and a cam that size would net less than an aftermarket intake manifold. Have I lost compression somewhere? Is something leaking? I saved for over two years to get all of this done. After all the research ive done, this seems wrong.

[Whamhammer]

The original dyno'd at 418. I have no idea how 225cc heads and a cam that size would net less than an aftermarket intake manifold. Have I lost compression somewhere? Is something leaking? I saved for over two years to get all of this done. After all the research ive done, this seems wrong.

Could the cam have been installed a few teeth off on the timing chain gear?

[Whamhammer]

I think they cleaned up the piston tops and block surface but that's about it. It's the very same dyno used for the first cam. The guy also said that it didn't start making good power till around 6500. And even through ls2 intake is inferior I've been told by other shops that going with a FAST or similar product isn't something that's necessary. They successfully run 600hp plus cars with the stocker.

But if the manifold is leaking air...

[douglowden116]

How many cc's were the old heads . if you went to a larger cc head you will loose compression . I did that with a set of brodix heads and had to go to a higher dome piston to get compression back up .

[SMWS6TA]

Timing might be off like mention above. if you have a vacuum or compression leak your idle would be shit.

What size injectors are you using? Not enouh you run lean. bad for the engine and lost of pwr.

228 cam? That honestly is too small for those heads. You kinda are having something similar to me. I'm being held back because my heads. Mine are stock 243's so I'm at 450rwhp/tq for my 403ci. Once I get a good set of heads and a slightly bigger cam that will work better with my bottom end they'll put me in the mid to high 500's.

[dethinboots]

I'm running the stock 36lb injectors. Stock 243 heads are around 65cc. How can I get the shop to fix whatever is wrong? I would figure a manifold leak would be easy to diagnose. The shops also said it messed with the timing to see if that's where the problem stemmed from. I'll go talk to them today to see if we can troubleshoot. What hp and torque numbers do you think would be more accurate? Would a compression test identify anything wrong? These results have me at a loss.

[SMWS6TA]

it can't hurt to do a compression test.

The TF kit you got makes me wonder if the 500 number is at the flywheel or the rear wheels. If at the flywheel, subtract 20% for drivetrain parasitic loss and you're at 400ish to the rear wheels.

[douglowden116]

you need to talk to whoever made the heads and see if they recomend stock pistons with that set up . they may be able to answer your questions .

[dethinboots]

It's a 550hp kit and is to the flywheel. Seeing people come out with 480 to the wheels with autos is why I'm concerned. What's more concerning is that I only got 439 when the air filter was removed. I haven't seen anyone else with this kit swap pistons either. Some do injectors but the result is still similar.

[dethinboots]

okay I feel like a noob. ive found article after article about how cars with high stalls do dismal on the dyno. The formulations for power and torque a severely altered when recording a stalled vehicle. this means that the results will always be inaccurate and very low. Reading these articles didn't really give me any peace of mind until I had the opportunity to drive her when I picked her up from the shop today. All I can say is wow... The car is a monster. So as long as I'm running a stall the dyno will only be used as an aid to tuning. Thanks for hearing me whine and trying to help out. I guess next time ill do a little more research before I begin to panic.

[Firebirdjones]

I was going to say an auto with a good stall converter won't be a dyno queen. Back when you were running the smaller cam I seem to remember you didn't want to do a converter at that time. So that dyno session is likely apples to oranges.

Now with a converter in it, 440 rwhp is actually pretty healthy. Get it to the track where that converter proves it's worth and you'll change your mind on the RWHP numbers.

[0rion]

I still say you should've saw more than 20HP going to trickflow heads and a bigger cam. Don't get to hung up on the numbers though. Take it to the track and see what your real results are.

[dethinboots]

Firebirdjones is right. The previous dyno was without a stall. As soon as I drove the car i could tell that it was a different beast all together. I'm really excited to get to the track and see how she does. I'm sure it will not disappoint. Especially now that everything non essential has been stripped out of the car.

[SMWS6TA]

You want to know what is going to make you sad......... later on after you get use to this pwr level you're going to want more....


I'm already a yr out from my rebuild and want to start on my next pwr level. Only thing stopping me is I want the car repainted and the T56 transmission to get built to stg 3 1st.

The heads I'm looking at plus cam are an investment. Hell almost as much as a turbo kit