Am tinkering with my tune and am going to try to hit the track again Friday. Can someone give me an idea what trap I should be expecting when the tune is on target for the following setup?

99T/A with Stock junkyard LQ4 with 799 unported heads and stock gaskets, LS6 intake, 228R cam, A4 with 3600 stall, 3.73 gears.

With a questionable lean tune last time it ran like 12.48 at 111 and that seemed really low considering the LS1 bolton that was in it just before this ran 12.5x can't remember trap, guessing 107. The LS1 had stock heads and cam. I understand that the LQ4's extra 100lbs is 1/10th but seems like this setup should be trapping higher.

Thanks

 

So as far as weight nothing else has changed except the iron block? Basically no weight reduction?

 

Correct, basically I pulled out a kncoking LS1 and replaced it with LQ4 using all the LS1 pieceparts like accessories and oil pan etc., and while I was at it I added 228r and 799 heads, everything else the same right down to the tires.

EDIT: of course I changed the pushrods and springs and did brass trunions as part of the cam package, but everything else from the LS1 carried over.

 

what stall converter are you running? Same as befor with the LS1?

 

Yep, same stall. A lot of the tune is the same too (all the trans stuff including shift points and TC lockup etc). Just did the typical IDLE/VE/MAF and now WOT tuning with my wideband. Seems to run very well, anything under 20mph will break tires loose at WOT. It used to be anything over 10MPH wouldn't spin. So I know the lower torque is better for sure.

EDIT: Last time when I ran it, it had a dirty fuel filter and had it really dumping fuel at WOT, but the log showed it kept a good solid 13.XX AFR all the way through, so I assume that 111 was a solid representation of my setup. That problem is fixed, and am expecting to peg a 12.8 AFR which isn't that much different. Trying to figure out how deep to look into this. If 111 is about normal for my setup then that's fine, just sounded low. I would be a little disappointed that these mods and the work involved netted so little gains. Bolton LS1 versus H/C LQ4 gained only a few tenths and say 5mph?

 

whats your elevation or what was the DA when you ran?
Seems low I would think closer to 120 atleast high teens unless you lost half the track to tire spin.

 

Without knowing the DA it's all just a shot in the dark.

 

Will check to see, I think that used to be on the timeslips if I recall. But it's in the Pittsburgh area. Same track likely very similar weather both times but will see if the slip states this.

 

Only had a bit of a spin at launch but I think I did 1.9 or better 60-foot. That normally doesn't affect my trap with just a little spinning off the line. If I get this tune dialed in I'll get some fresh runs and gather info like temp/DA etc and maybe post a timeslip and see what you guys think. Yea was hoping to get a full 10MPH at least over the stock bolton LS1 after all that money and work LOL

 

If you find your slip and it has the date and time you can find a DA calculator online that lets you input your track's name to look up weather data for that date and time.

I would venture to say 111mph is a little low.

 

Did a track run last night and I think I have all the information anyone could ever need for this LOL... dragtimes.com shows:

Density Altitude: 1212 feet
Relative Density: 96.5 %

...for Pittsburgh last night around the time of my run.

Attaching time slip, an HPTUNERS log of this run, and my tune that was in it at the time.

Talking to others at the track I really think this should be a better trap, and I'm missing "something". Car is stock weight, no spare tire and no sway bar but has AC and everything else, 250lb driver.

I know the 60' was horrible, not sure what happened in this run, I think I staged a bit too deep because one of the staging lights was flickering, I think the starting line eyes might have robbed me a bit on the ET. But low 60' has typically not affected trap much or at all.

Also, this run was with 87 octane because it was a short notice decision to run, and I decided to run it on the daily gas rather than load up the weight and mixing in gallons of 93, besides prior to this I had never seen KR, but obviously this time there was a little. But last run with the 93 it also trapped 111.

I do have one other pass where the numbers are very similar but had a lot of wheelspin, still trapped 111 and still ET'd at 12.7ish.

With the LS1 earlier this year I was able to get a 1.8 sixty pretty regularly, just need to find the balance with all the extra torque. My ET will likely be ~12.4ish I figure based on this right now. I hit 12.5's and routinely did 12.6's with the bolton LS1. I just need to find out why I am down on power with this cammed/heads LQ4.




Thanks guys, maybe I'll also post this info in the tuning section if this doesn't get enough visibility here.

 

 

Absolutely agree. I never touched timing advance yet, but will. But that's probably not going to get me +8mph trap, right? seems like I'm missing something else. Something much bigger.

This is a DD for me so I'm eventually going to do some timing testing and eventually have dual tunes, one I can run 87 with.

 

 

For what it's worth. the timing in there now is the exact timing that allowed a bolt-on stock-head stock-cam LS1 run 12.5's at I think 107. Never touched that part of the tune, not sure if that really means anything or not.

But this particular run was actually not rich at all, pretty close to commanded 12.8 as shown in the attached log, the run included a LC2 wideband channel for everyone's reference.

And the valvespringe are the dual springs that come with the TS 228R kit, forget the brand, but certainly not stock ones, I would think those would be fine. Pushrods too. Good thought tho. Maybe I'll pop off the valvecovers and just take a peek and see if they are all OK, I expect I would have some sort of symtom if one broke or something, I'd expect to not run this well. I've now got over 2k miles on the build, and am really having no other symptoms.

 

 

Wow, just browsing through the captured run in HPT, I see while I was coming up to the line my IAT was like 135, and only came down to 90ish at the end of the run. That's something I need to check in to. The previous owner did cut out the bottom of the airbox presumably to let more air in, must be getting heated air from the radiator. I don't know the effect of that however, but have added that to the list of todo's with the timing improvement.

Anyone know how much that matters on a run like this? Actual outside temps were WAY lower than that, like 55-60 I think.

There was a lot of waiting at the track, was a very busy night and two cleanups, only got 2 runs in 4 hours.

 

 

I thought of heading over but figured with decent weather and the weekend event that Friday TNT would be packed. Even though it was cool out, the air was fairly humid if I recall correctly. Some if your combo looks similar to mine except I'm still 5.7l, LS1 intake and 853 heads. The other week at PRP I went 12.17 at 111 mph. I'm still tweaking the tune and think it has a 11.99 in it if I can get a clean pass in good air. PRP seems to always be slower than other tracks when comparing similar builds.

 

You didn't miss much. On the streetcar side, I believe all lanes were filled all the way back. I got there at 8pm and sat forever while they cleaned the track, then got 2 races in, and around I think 11:30pm someone dumped out fluid all over left lane and they eventually decided to just call it a night. Wish there was a way to know how packed they were going to be ahead of time.

I have a friend who has cammed Ls1 with 243's and hits high 11's usually at 115+ at PRP. I thought I'd be at least close to that with similar 6.0L. There's gotta be more to my problem than timing optimization and heatsoak, but we'll see.