JDMC5

iTrader: (3)

I just looked at a stock tune for the LS4 and to be honest it doesn't look bad. What is typically done to these tunes to pick up power? The air/ fuel and timing both look good. I'm going to tweak the DOD and the shift points but other than that I can't see room for much improvement. Anybody want to chime in here?

TiredGXP

iTrader: (2)

Check out the PE table - JMHO, but I think GM left a bit of torque for us to pick up by leaning the PE AFR out. For 2005, the PE AFR gets as rich as 12:1. I set it to 12.8 across the board.

PE Enrichment rate is low, increase to 1 from .02, also consider removing the delay for entering PE and allowing PE to come on earlier.

We only have 91 octane around here, so there's not too much room to move timing. I have maybe 1.5 to 3 degrees more timing in the WOT cells, no KR.

I only have a few mods, but still had to make changes to the VE and MAF tables.

JDMC5

iTrader: (3)

Thanks for the reply. This is for my friends car an 07 grand prix. Yeah I noticed the A/F starts off at 13.0:1 and leans out to 12.1:1, but from my experience the actual commanded A/F will probably be richer. I think in my vette it was closer to 11.5:1. I'm looking at the timing tables and they look pretty good. Hopefully my buddy's car doesn't have any kr issues so I can add timing. I assume about 28* is what they prefer, like my ls1. I guess I'll just have to scan and see what timing and A/F the car commands while in the car. (IIRC my vettes actual a/f ratio on the wideband was WAYYYYY richer than what the PE table was commanding).

I'll probably fiddle with the AIT spark tables and trans shift points. Any idea what shift points are good? I noticed the second gear shift point is like 5400 so I'll probably bump that up to 6K so he doesn't have to use the paddles. I'm not going to mess with the firmness though since I know these transmissions are garbage. I also have a 2K GTP btw.

Mels SS

iTrader: (1)

Before you get to far I'll say Welcome to the board

Panther427

6k rpm is probally to much, i remeber seeing someone saying the stock valvetrain was inefficient above 5400, 5500. This was more due to the restrictive intakes we have, But the high volume of airflow needed is not met.

LS4SPEED

iTrader: (3)

That is incorrect, the intake has little to do with max RPM. The problem is trying to pull over 6K RPM with stock valve springs, they are weak and will lead to valve float. Setting your up-shift from 5500 to 6K will be good but also set the rev limiter up another 100-200 RPM as we'll to make sure you don't hit it.

JDMC5

iTrader: (3)

I can't believe the powerband doesn't extend much past 5400rpm, seeing that the engine's max power is rated at 5600, sure the power probably dips off but I'm sure 6K is fine. I'd love to see how much power would be gained by switching to an LS6 intake and TB or maybe a fast 90/90, I wouldn't be surprised it there was 25-30 hp hidden there.

Thanks again for the replies. A little info on me: I'm new to this sight but I'm sure I can offer good advice for those in need. I've owned several 3rd and 4th gen F-bodies and I currently own an 03 vette with spray and a modded 00 GTP. I also have experience with hptuners and I have a wideband. I live in the detroit area too.

As far as the LS4 goes, I think it has tons of potential with those amazing cylinder heads. I think GM really restricted it with the intake/cam and exhaust they chose. They could have EASILY made 350 hp from the factory but they detuned it for obvious reasons, FWD, trans, etc. I've seen what can be done to a truck 5.3 and the LS4 is only better.

Bryan921SS

The biggest let down in this car is the tranny. If GM would have made it a 5 or 6 speed then DOD/AFM wouldn't have to exist, and thus we would have more options for intakes etc.

bigcap

iTrader: (2)

I would love for FAST to put on an Intake for the LS4. Hell even a Typhoon.

JDMC5

iTrader: (3)

I agree the trans is trash, however I have the same one in my GTP and I just hit the 100k mark and the trans is still going.

5 or 6 speed, OR better engineering. I don't get it though. I get 30 mpg on the freeway with my vette with pretty much the same gearing 2.73 vs. 2.93 plus I have a bigger engine and no DOD well 500 lbs less helps too but still.

bigcap

iTrader: (2)

I had a GTO with the 4l60 and it blew. I had modded it to over 450 RWHP but that tranny was much better then the Imp tranny. I wouldn't want to mod the LS4 too much for fear of buying another one. They sure are expensive.

JDMC5

iTrader: (3)

I agree, thats why I keep all my torque management active for shifts. I've gone through about 5 bottles with no issues at all however I only have about 40K on the car. That 2.73 allows me to hit the spray in 1st with street tires so it works out. I know the vette A4 is a little better than the f-bodies, not sure if the GTO has the better one. You know you can get a built tranny for your car but you're right they are pricey.

bigcap

iTrader: (2)

I put a perfomabuilt tranny in my GTO and it had the 4l65E.

TiredGXP

iTrader: (2)

Well, here's my WOT shift tables (converted to mph)



Upgraded valve springs and pushrods - never noticed any valve float the few times it hit 6250 in first. Rev limiter is set to 6300 in first and second, 6100 in third.

I removed engine torque management, half of the transmission torque management, and bumped the shift pressure a small amount. (about 18 months ago).

JDMC5

iTrader: (3)

I see, I'm sure leaning out the top-end, CAI and adding those rockers improve top-end performance allowing more usable power. I wish I could convince my friend to add those rockers. BTW, do you think its possible to bump the factory 303hp to 330 with the intake and tune? That would be about 22 whp which sounds quite possible.

Panther427

If u read my post about dyno tune. Im aprox at 330 if u figure a 20percent drivetrainloss. I do have a dyno graph showing 264 ON ONLY A TUNE... using HPtune. I will try to get them posted tommorow

TiredGXP

iTrader: (2)

I find that at my altitude (2200 ft) it's rare for the dynamic cylinder air on the LS4 to exceed .68g/cyl. I occasionally see .72g/cyl; at that air density, the stock Hi Octane timing table provides for 24.5* at 3000 RPM rising to 27.5* at 6000 RPM. I'm running between 27.5 and 32.5 in that RPM range. (at lower dynamic cylinder air densities the difference is less, the stock tune really dumps quickly between .64 and .8 g/cyl rows.

JDMC5

iTrader: (3)

thats funny you say that because my vette, my friends WS6 and my other friends trailblazer all hit about the same g/cyl at WOT as yours and I live in MI which is about 500-1000 ft above sea level. I noticed those table drop off quite drastically.

Panther427, would it be possible for you to get a copy of your bin from the tuner? I'd like to see what timing you have

Panther427

Ill ask him...

Panther427

well im sure u could ask him. He is part of coloradolsx.com.. His his name is clint.