rp0029

iTrader: (1)

So I finally got my car dyno tuned (68 Camaro). Dan from Masport in Palm Beach (Boca) did the job and he did great. What a terrific guy to work with. Really knew his stuff and even helped me troubleshoot a couple of issues which he identified right away. The guy couldn't be friendlier.

On to the results:

The engine itself is a 6.0 l silverado iron block with a stock bottom end, LS3 heads, LS3 intake/injectors, and a 222/230 @ 0.50 cam with about .570 lift on a 114* LSA. It has mid length headers because LTs scraped the ground. This engine is going through a 4l80e with stock converter to a 14! (yes 14) bolt 3.42 rear end from a truck (with a true trac posi and 33 spline moser axles), so I expected some parasitic loss.

On a Mustang Dyno, the car pulled 301.3 RWHP with 315.0 RQTQ with a load corrected for 3800 lbs. The problem is that it ran out of fuel at about 5400 RPM. Dan thinks it is the fuel pump so I am going to be replacing my cheap spectre tank with one of the aeromotive stealth tanks. While I was hoping for closer to 400 rwhp I guess that the mid headers and the beefy rear and tranny just took some HP away - Dan thinks as must as 80 HP are being lost from the engine to the wheels when compared with a 4l60e and a smaller 8.5 10 bolt rear, and says the engine probably makes about 450-500 at the crank.

Drivability is excellent, very happy with the part throttle and idle tunes. Strange that this car doesn't "feel" like it is putting 300 hp to the wheels. My old 99 trans-am actually had more seat of the pants "oomph" and made 297 at the wheels with just LT headers and a tune.

Do LTs really make that much of a difference? Also, would a stall help?

Lonnies Performance

iTrader: (16)

Your tuner is not far off with the 80hp wasted in the driveline...

You picked the heaviest & most power consuming parts, using a 4L80E & a 14 bolt.
The trans & rear probably added 250lb. extra to your car.

You should at least use an aftermarket converter in the trans. Those stock converters are about 80lb alone & consume a ton of power to turn.

rp0029

iTrader: (1)

I picked them because I do not want them to break. I have heard story after story about the 4l60e getting shredded with 350 hp. When it came time to pick a rear, I went with the 14 bolt because it was about the same price as the 12 bolts I was seeing, but stronger. I just felt that this drivetrain will never break. But it was a little disappointing to have numbers right around 300 when futureuser got 395 with a 4l80e with a stock stall and a 10 bolt 8.5. I think his dynajet dyno was not stingy like the mustang I used (I read add 10% for the dynajet).

You're right, next stop is to fix the fuel pump and to get a stall. If I'm still not happy, we'll be going with a stroker next year. Any good stall recommendations?

toxic99

You went over kill on the drivetrain imo. 12 bolt would have been more then enough for anything a hot N/A LS motor could throw at it. And alot more tbh. Especailly with you running an automatic setup. And the 4l60e thing is debatable for a built one, depending on who built it. Stock ones? Sure 350rwhp will do them in np. Built by the right shop, highly doubt it. My built one still lives in a 3800# low 10sec nitrous car and is around 6 years old. But nothing is unbreakable. I dont think you are remotely close enough power wise to blow up either. JMO and GL with your setup.

PS stall will make a big difference too. Dont be affraid to go big.

rp0029

iTrader: (1)

Thanks for the opinion. Hindsight is always 20/20.
Aside from a stall, (and something like adding a blower or a stroker) what else do you think I can do to make it have more seat of the pants power?

rp0029

iTrader: (1)

So if I go with, say a 32-3500 aftermarket converter, how much more HP will get to the ground?

weircc

iTrader: (6)

what brand of cam? im building same setup 6.0 ls3 top end with eps cam he told me with the right tune i should make 480hp at wheels no problem and i see guys with same build in mid 400's all day. now im no expert and mine isnt done yet so im just asking but i agree a 14 bolt and 4l80 has to be robbing you of some serious power. my 70 camaro had a built 468 roller motor with a m-21 muncie and a (10 bolt) not stock but not super high end either and never had a problem with rear end and believe me that car got *** raped every time it left the garage. car ran mid 11's on motor im guessing was close to 500hp at wheels

rp0029

iTrader: (1)

It's a comp. Was designed by Patrick Guerra for my application. I'm sure some day I'll be adding some bigger cubes and possibly a blower or nitrous, and furthermore, I really just don't want to spend the additional money for yet another rear end/tranny, so they are here to stay. Like I said, hopefully a stall will help, but that isn't for another month or two.

Rocketrod

iTrader: (2)

I think your expecting to much out of a new stall converter as it will not magically add the 80hp or so you have lost due to the 14 bolt rearend and 4l80e. If you really think more cubes, blower or nitrous is in the near future I wouldn't get to hung up on the numbers. Just drive it and enjoy it for now...

Bo185

Is it the 9.5'' semi-floater with disk's which has 6 lug or 8 lug options? So its not as heavy as the 14bolt 10.5'' full floater with drums or disks would be. And the 3.42's with the poor first gear of the 4l80 will kill your seat of pants feel from a stop especially. I would swap to 4.10's.

Was it an LQ9 or 4 bottom end? And whats your CR? It might be that if it's dished pistons might be leaving some CR on the table.

rp0029

iTrader: (1)

I'm not hung up on the numbers. I am hung up on the fact that it feels like a dog down low when compared to my 99 TA, which had everything stock except LT headers. A 6.0 with an LS3 top end should whomp an LS1, but sadly it doesn't. Less low end grunt, which is strange.

This car is a daily driver. While I don't need it to feel like a 600rwhp beast and to go sideways when I floor it on the interstate, I would at least like it to feel like it is making the 100 more HP the engine makes than my LS1. Dan said it is putting out about 450-500 easy, just 80 or so extra HP is wasted with the heavy parts. Remember, dry a stock 68 camaro weighs 3050 whereas a ta vert weighs 3400.

So I can try to get the additional HP by going with expensive forced induction or additional cubes, but here is what I was thinking:

First I will get a stall. Hopefully that by replacing the 80lb stall with a 30lb one with more of a torque multiplication factor I will be happy with it.

If that isn't enough I can get a junkyard 10 bolt 8.5 Nova housing like it says here, and get an eaton posi carrier and 3.42 ring/pinion from a truck and some moser axles. That should live on the street with my car and allow for some pretty awesome 40-70mph roll on blasts. I can probably build one for less than $1000. I can then sell my 14 bolt to someone who needs the rear. If the stall doesn't to the trick.

This would be a lot cheaper than getting the cubes/blower for the same effect.

Bo185

I would fix your fueling issues first then redyno it before swapping axles. You won't high hp number till you get above 5400 rpm's anyway! Then I would just do a gear swap in 14 bolt to help with taller first gear of the 4l80e.

rp0029

iTrader: (1)

I really do not want a taller rear gear. It is a daily driver with a lot of highway driving, and to do a 4.10 out back would make it scream at 75 mph.
One of the amazing things about the t/a was that it had some serious low end grunt but it also had 2.73 rears. It would do like 1600 rpm at 60mph.

3.42 is about as high a gear as I want to go, but if you have other suggestions I am all ears.

toxic99

Like most have said, fix your fueling issue first. But, a stall will def. help with seat of the pants pucker . Wont increase power but it will help you feel the power you do have as well as increase your cars performance. I wouldnt go smaller then a 3800 imo. These motors rev and make peak torque pretty high in the rpm band, hence the need for higher stalls then say conventional SBCs. I would also revisit the LT headers, maybe another manufacturer. Mid lengths = poo. After that, id you're still not satisfied, I would say go blower if the pocket book permits.

cookba

iTrader: (10)

fix the fuel. throw a 3600 or a 4000 (i would go 4k) stall converter in it. i recommend FTI for the converter. And you would have been fine with a built 12 bolt or 9" with your intended power level.