jclayc

iTrader: (8)

You might have seen my posts about struggling with what I think is light flywheel stalling in my recent rebuild but, perhaps related to that is that my dynojet numbers suck given my mods. Other than "get a new tuner" anyone with thoughts?

389hp, 363tq from

• LS6 block w/ forged pistons, forged H Beam rods & balanced crank
• Trick Flow 220 heads
• Comp Cam 229/239 .627"/.621" 111.5+3
• 63lb injectors
• Fast 92
• 90mm LS2 TB
• LS7 clutch and light RAM flywheel
• high vol/high press oil pump

isis

iTrader: (1)

Can I ask how you are sure it's not the tuner? Car won't idle right or make 'good' power for the mods.. Just curious how that's ruled out so quick.

Isn't the stock fuel pump a bit strained for that list?

05CTSV

iTrader: (16)

For comparison my LS6 made 399.9hp and 367.8tq with stock bottom end, stock intake, stock injectors, stock throttle body, and stock heads. Only engine mods, cam, comp cams trunion upgrade. Has headers, monster stage 2 clutch and 28lb flywheel.

Dyno numbers can be funky though depending on lots of things. Tuner, calibration, condition of the equipment etc. I'd think with your setup you be above the 400 mark for sure.

serik21

Can you post a dyno graph with your a/f?

barrok69

What were you expecting it to make? You're making 50rwhp over stock with just H/C/I.
You should probably match the TB to the intake as it is currently acting as a restriction. And do you have Headers installed? (not familiar with what was already in your car)

Onefast V

iTrader: (3)

looks like it has a correction factor of 0.97 so your uncorrected numbers are 401/374

jclayc

iTrader: (8)

i'm definitely not ruling out the tuner... the low numbers + his apparent problems solving the return-to-idle stalling make me think that may be the primary issue

yes, I have Kooks headers (they are 1 3/4 and not 1 7/8)

and most of my brain agrees that 50 rwhp over stock is in the right ballpark but I also see Fuzzy making 420 something with no heads, lolly making a reported 422 with 215 heads and the "how to I make 450-500hp?" thread recommending h/c/i to make 450 and it makes me wonder

I have a racetronix kit I'm going to eventually install and perhaps a 255 fuel pump. My injectors show like 1-7% capacity (I think)

isis

iTrader: (1)

I think the 'one dyno vs a different dyno' could account for 20 hp or so but yeah, it sounds like you have what's being suggested in the other thread to make 450.. Which I'm not sure would likely be just the dyno.

But I'm gonna bow out here, since what I've heard is what you've heard and is all I really know, and that means I don't really know. Good luck.

odthetruth

iTrader: (4)

Compression test. If all is good, new tuner. Lol

05CTSV

iTrader: (16)

Sounds a lot like the first tune I had. The tuner could not get the car to idle at all. It would for a minute or two then it would stall, rev high, the idle was like a yoyo. He blamed a dirty MAF, then a battery issue, then finally I called BS, got my money back and took it somewhere else. The new tuner had it idling within 10 minutes before he even pulled it out of the parking lot. His guess was that the previous tuner only tuned the MAF portion of the tune and not the VE tables. He tuned with the MAF tuning off, dialed in VE then tuned the MAF portion. Maybe your tuner has done something similar, 1/2 @ss tuning.

jclayc

iTrader: (8)

good thought on the compression test - even though the engine builder is "known"

i may end up taking it 4 hours north to Slowhawk Perf in Mass - from Fuzzy, I know they solved the same issue for him

FuzzyLog1c

iTrader: (4)

It's hard to tell whether there's a problem or not. It does seem a little low, given your heads, but it is a LS6. The compression check couldn't hurt.

Have you tried a 4.0" intake with 4-ply silicon couplers, a 4.0" LS3-style MAF, insulated airbox, and a relocated low thermal impedance IAT sensor? You could implement most (if not all of it, depending on your airbox selection) for about $400, and it'll support future engine modifications.

jclayc

iTrader: (8)

The bigger intake and IAT aren't a bad idea - there's a thread out there on it that I'll find when I'm off mobile.
The thread will prob answer my questions but doesn't the IAT bung require welding into the tube? And splitting the IAT wires off my 5 wire MAF?

bmylez

iTrader: (3)

Fuzzy, I adapted a 4" tube to the stock MAF and K&N air box, which obviously doesn't sit right anymore. What did you do for a custom air box?

FuzzyLog1c

iTrader: (4)

I really like the Lingenfelter airbox, which fits tightly against all sides of the engine bay and hood. The K&N looks like it has major air gaps. The last time I was tuned, my IATs were 15-18 degrees over ambient at idle, and 1-3 degrees over ambient in motion. Keep in mind that these numbers were only achievable after I added aluminized thermal insulation to the bucket.

The LS3 MAF tube that I linked you to earlier has the bung already welded-on and includes a nice air straightener. If you have any questions, give the shop a call--they're good guys. You'll need an adapter from Casper to break out the IAT sensor (they also sell low thermal mass IAT sensors) and convert your harness to the LS3 slot-style MAF sensor connector.

There are a plethora of threads on LS1Tech that provide enough information to help your tuner recalibrate for the slightly different impedance of the LS3 sensor. This should go without saying, but wait to install the MAF until you get to the tuner. The difference in MAF diameter will reduce air flow velocity for a given condition.

While you're messing around with this stuff, this Spectre GM MAF 3-5/8" to 4" adapter might be useful to hold you over.

01_SuperSlow

iTrader: (7)

BS, those numbers are low, even for a LS6.
Even though I haven't modified the LS6 in my V, I used to have a 01 SS with "only" a LS1, and it got me 407rwhp and 368rwtq on a dynojet with cam only (232/240 .595/.609 112), LT headers, 25% ud pulley, lid, and tune. Stock heads(241), stock intake(LS6).
For the mods jclayc has, I agree those are sorry dyno numbers.

FuzzyLog1c

iTrader: (4)

Yes, but your SS has a more efficient drivetrain. The stock CTS-V drivetrain inflicts fairly significant losses due to severe misalignment. This also affects the LS2 version of the car, which has a slightly improved differential.

cts-vls6

iTrader: (7)

What is ur A/F at wide open throttle

itsslow98

iTrader: (18)

That setup should be around 450rwhp even through a cts-v driveline. What is your compression ratio?

He would have to be a horrific tuner if he left 60rwhp on the table with the tune alone.

FuzzyLog1c

iTrader: (4)

The most I've ever seen a LS6 make on a believable dyno is about 430 RWHP. I would be lucky to achieve 450 RWHP with my LS2 and ported heads with a FAST 102.