2SLO4ME

iTrader: (39)

OK So I did a LS3 Swap and looking at other cars that come with LS3's I just feel like I am down on power. I dynoed 434.32 rwhp and 413.37 rwtq and that was with the muffler disconnected from the exhaust so basically a cutout open in the I-pipe. The tuner did say that his dyno reads low and that vettes will dyno 430rwhp on his and then dyno 450rwhp on others. But even at 450rwhp I feel like that is low. I have full bolt-ons and a Vengeance RD LS3 Stage 2 cam which is proven to do 480rwhp with not head work and a stock intake manifold. Here is a thread to an example: Click Me.

Here is a full list of my mods:
Engine Specs
2008 L92 6.2L Short Block - Rebuilt (Hone Cylinder Walls, Polished/Mic’d Crank, Clevite 77 Cam Bearings, Clevite 77 Main Bearings, Clevite 77 Rod Bearings, New GM Rings, Stock L92 rotating assembly)
LS3 Front Cover with Cam sensor

Valvetrain/Heads
Stock L92 cast heads, 10.5:1 Compression
Stock Rocker Arms
LS3 Intake and Exhaust Valves
TEA Dual Gold Spring Kit, .650 lift
LS7 Lifters
Comp Cams Chromeoly Hardened 7.4 Pushrods
Vengeance Racing LS3 Stage 2 Camshaft: Renamed Stage 3 on new online store
LS3 Timing Chain Dampener
3 Bolt 4X Cam Gear
LS3 Timing Chain
LS6 Oil Pump
Stock GM MLS Head Gaskets

Transmission
Stock T-56
LS7 Clutch Kit

Rearend/Driveshaft
Stock 3.42 Gears
Stock Aluminum Driveshaft

Electrical
Lingenfelter Performance TRG-001: 58x to 24x Converter Box
85mm Delphi MAF with Adapter Harness
LS2 Knock Sensor Adapter Harness
MSD 8.5mm Super Conductor Spark Plug Wires
TR-5IX Iridium Spark Plugs
Yellow Top Optima Battery
LS3 MAP Sensor: Delco
Injector Adapters

Induction
LS3 Intake Manifold
FAST 90mm Cable Driven Throttle Body
85mm TSP Lid
K&N Drop in Air filter

Fuel/Cooling
L76 Fuel Rails
40lb LS7 Injectors - Adapters for LS1
Twin Walbro 255lph In-Tank Fuel Pumps

Exhaust
Pacesetter Headers Off Road
Custom Y-pipe into a 3.5” Flowmaster Merge
SLP Dual/Dual Exhaust

Here is a Video and Picture of the Dyno Graph: Also the AFR is spot on.
Dyno Run

jmilz28

iTrader: (13)

Well, the Dyno is a known variable. Some have been known to say that to cover other issues. I'm not saying that's the case since I don't know your shop, but it happens. In that vein, who did the tune?

I'm also very suspicious of rebuilt low mileage engines. Why was it rebuilt? Who did the rebuild? Who did the machine work?

I think you're giving up 10hp with the Pacesetters, personally, but that certainly doesn't explain all 50rwhp difference.

I'm not a fan of non-GM plugs and wires, it's unnecessary for most, unless they're spraying/FI and need colder plugs. Seen this be a problem with my own eyes.

I think one or a combination of the first three is your problem but there's just going to have to be some good old fashioned trouble shooting here. If it's in the rebuild, the only way to figure may be to tear down and starting mic'ing. I'd have just gone with the GMPP crate 376/480 but IIRC, you worked out a trade on this deal?

novaflash2002

iTrader: (51)

i dont know where you got the 480 rwhp , but it would be over 490hp at the flywheel if you did an engine dyno. usualy a 12 to 15 % loss

69LT1Bird

iTrader: (1)

I will say the tune is off.

Detroitmuscle

iTrader: (16)

dynos are for tuning purposes, get it to the track and see what it traps before you start calling anybody wrong.

WKMCD

iTrader: (2)

The LS3/L92 builds can be tricky to cam. What are the specs?

69LT1Bird

iTrader: (1)

From a Vette forum, Ron says these are the specs.

235/243 .621/.623 115+4

Then they thought it may be

231/243 .621/.623 115+4

2SLO4ME

iTrader: (39)

I got the Short block plus oil pan and assembled heads in a trade for an LS1 I had laying around. Had I not gotten the trade I wouldn't even have considered putting a LS3 in the car, though a crate would have been nice and might have been cheaper in the long run.

The trader said that it only had about 2500 miles on it but when I went to take out the VVT camshaft I noticed that the cam bearings had A LOT of wear. So in order to get them changed I had to strip down the block and I figured I would get everything freshened up at a local machine shop around here while it was all apart. I order all new bearings and rings and checked all of my clearences and they were all within spec.

I figured my exhaust setup would be a little more restrictive then the vette thread I linked so I am by no means expecting the same output as him.

I will definitely check into different plugs and wires when I get it dynoed again after I get my FAST 102 and dual cutouts installed.

And lastly the tuner was Baker Engineering in Michigan. They are an amazing shop and have been around for awhile so I'm not putting any blame on them.

I got it from Vengeances Website and if you click the "Click Me" link in the first post in the first paragraph you will see someone that got 480rwhp with this cam.

I hope you are refering to me with the last part. I am by no means saying that anybody is wrong be it the tuner or Vengeance, I am just merely asking a questions. The only thing that me and that vette have in common is a LS3 with the same cam. There are to many other different variables for us to come out with the exact same numbers, but I thought I would be a little closer to those numbers.

Look Below

I know that the numbers aren't advertised on his site so I won't say them but one of those two are correct.

Detroitmuscle

iTrader: (16)

I'm not directing that comment towards anyone just stating that dyno numbers don't mean a whole lot, track times will paint a much bigger picture.

2SLO4ME

iTrader: (39)

Ok, yeah I would agree with you on that horse power means nothing if it's not usable. I just need to not be swamped with work and school so I can actually make it to the track.

jmilz28

iTrader: (13)

Yeah, some trap speeds are going to give you a firmer idea of just how far off you are from where you should/could be. Do you have any comparables from that dyno?

FWIW, I'm not looking to place blame on anyone, simply figure out:
1. If there is a problem, what it is
2. How far off you are, how bad is it
3. Is there more than one issue
4. Figure out the solution(s)

NO shop/tuner is immune to mistakes, getting in a hurry, etc.

Has a good machine shop been through the heads?

novaflash2002

iTrader: (51)

no where on the "click me" does it say it will give you atleat 480hp. that dyno graph shows that vette with only 473.60 hp. the specs on the cam from vengnce is Vengeance Racing Stage II LS3/L92 Camshaft 227/239 .614/.624 115+3

2SLO4ME

iTrader: (39)

When you say comparables do you mean other cars on that dyno or me on other dynos with this car... And I don't think that you are trying to put blame on anyone.

I know the questions are more rhetorical but I'll answer one:
1. I am not having any issues with the car and how it runs. It seems to pull smooth and hard.

Should I get a compression check and see if anything is low there... That would affect power right... The spark plugs have a nice color to them... Spark seems to be all there. There isn't any gas smell when the car is running either. I don't have any exhaust leaks and I don't seem to have any vacuum leaks.

The heads were actually brand new never used so there shouldn't be anything wrong with them.

OK 473 is no 480 but it's damn close. If you go to Vengeance's new online store they specifically state that the camshaft that I have chosen with supporting bolt ons is capable of producing 475WHP. Vengeance's old online store said 480-485rwhp and after checking the new site it looks to me that they changed the cam that I bought to the Stage 3 and no longer the Stage 2. My cam specs are 231/243 .617/.624 115+3. Here is a link to the old store: Click Me

jmilz28

iTrader: (13)

I'd get a compression check, just for my knowledge. At least that will rule out several possible mechanical problems.

Yeah, comparables meaning all of the above - whatever you can get. If there are others who dyno'd at that facility and another, that will help give you an idea of how reliable and comparable that dyno is to others. Get yours dyno'd at another also, which will help some too...just for reference. Finally, as mentioned and maybe most importantly, get to the track and see what you trap.

Frankly, if you hit the track and end up trapping what other 450 rwhp cars (of similar weight) are, I'd stop sweating it. I'd also figure up what kind of fuel mileage you're getting, just to have an idea of how efficient the combo is. Of course, this requires keeping your foot off the loud pedal. I can imagine how hard that would be right now. LOL!

2SLO4ME

iTrader: (39)

I'll try to get a compression test tomorrow and I'll see what I can get as far as dyno comparisions. There is a Dyno Day here in Michigan coming up soon and we will see what I come up with. I'll also try to get to the track soon and see what I trap.

As far as MPG's With me riding it hard I got around 20 MPG's on the highway. I don't think there has been one 10 Minute interval where I haven't had my foot all the way in it, haha!

The SES light did come on and I got the code checked and it said "Bank 2 Knock Sensor Low Impedance" you think the PCM is adjusting itself...

Also I had another thought... Maybe my cam isn't what it really says since the camshaft got changed from Stage 2 to Stage 3. The Comp Cam box it cam in says "231/243 .617/.624 115+3" but maybe it's a 227/239 .614/.624 115+3... Do you think that is a possibility...

2SLO4ME

iTrader: (39)

What's got me is I see people with LS3 swaps and a Hot Cam making the same power as me and that cam is significantly smaller than mine...

LS3Z28

I dynoed 390 rwhp mods in sig

LS3Z28

Without turbo

2SLO4ME

iTrader: (39)

I'm gonna bet the 2.5:1 compression lower and the fact that you are a Auto are why it's lower but as soon as you slap on that turbo you will pass me in the rwhp department SIGNIFACNTLY, haha!

jmilz28

iTrader: (13)

Those MPGs are good IMO.

No, I JUST fixed that same problem with mine (P0332) by replacing the knock sensor(s) and harness. If you reused sensors, maybe one went bad? Maybe pinched wire or corroded connector? At least you don't have to pull the intake to check. You probably used a knock sensor extension? Check that circuit...

Actually, that may be your power problem. When it senses knock, it pulls timing (power). It will throw that code a while before it tripes the SES light so that really may be it!

I really hope it's a sensor or connector/harness...for your sake. Otherwise, you're looking at a tune issue or mechanical.