dicky

my car is a bolt on LS2, 6 speed auto with a yank ss 3600 and 3.42s. The car makes 361 on a motor and 414 on the 75 shot and 526 on the 150 shot.

The short version
Yesterday i was running 7.16 @96 with a 1.56 60' on motor, when i sprayed the 150 shot i was only running 6.80 @98 with 1.45. After several tries i dropped down to the 75 shot and was getting 6.92 @98 with a 1.51. Would converter blow through be causing such little gain?

More detail
I been having trouble with the trans shifting so i went out and did some street pulls the other day and got it to shift great (bottle pressure was low for these pulls). When i get to the track and try the 150 shot it hits the limiter again (bottle pressure around 950 to 1000). I had to drop the shift points quite a bit to get it close. I scanned every run and the rpm drop after the 2-3 shift acts odd on the spray. It will flare just a tad right before the shift then after the shift it will drop from 6400 to 5500 like normal but then it jumps up to 6050 right away then drops again to 5450 and rises like normal from there. I had the window switch set to shut off at 6000 on these runs.

On the 75 shot it seems to do almost the something but i don't look like its flaring at all on the shift but it still does that weird rpm jump after the shift but not as bad. On the 2-3 shift it would drop from 6300 to 5250 then jumps to 5730 and drops back down to 5350 and rises like normal.

I'm hoping its as simple as converter blow through because I was already considering changing converters this summer.

Any help is appreciated

dicky

Here's a scan of the 150 shot run. Ignore the knock, it's my exhaust hitting on the launch. The 2-3 shift is what looks weird with that jump in rpm right after the shift.

HOXXOH

Add 1/2 or a full quart of fluid and go back to your original settings to see if you're starving the converter at high RPM.

dicky

I already got 1quart past full in there. Think I should add more?

C6David

If you are already a quart above full I dont think adding more is going to help. I noticed when I was running nitrous the gains on the SS4000 werent anywhere as good as I was hoping. At the time this is how the times looked.

Motor: 11.36@119 1.51 60ft
Went to a 150 and had all kinds of shifting issues: 10.9@125.8 1.49 60ft
Went down to a 50 shot to tweak the trans tune: 11.2@123.8 1.53 60ft
100 shot (trouble with the 3-4 shift):10.85@127 1.45 60ft
175 shot (28" tire to stay in 3rd): 10.494@131.2 1.45 60ft

Motor 408/408
Car dyno'd 513/480 on a 150shot
Swapped to a better plate and a 200 and the converter wouldnt even do dyno pulls. It was completely blowing through the converter. Dyno'd 532/453 and went slower. Did 10.6@130.

So after 2 nitrous kits, 3 sets of tires, and about 10 bottle I gave up, sold the nitrous, and said the single disk SS4000 is not too nitrous friendly for anything over a 100 shot. A triple disk converter would work way better. And I too had real bad issues with the trans tune. Once I got it dialed in I was in 3rd gear already at the 330ft with 28" tires on the 200 shot. Converter wasnt too happy.

On the upside I think I loosened the converter up a little bit so it 60ft better on motor now lol.

HOXXOH

If it were me, I'd add another 1/2 quart just for comparison. For just a couple bucks it's well worth the time and trouble.
At one time, I was 2 quarts over with no ill effects. Recently I changed coolers, etc. and forgot to add extra. I lost my 60' and ET by a bunch. Now at 1 quart over, I'm back to consistent 1.4's and 10.9's - 11.0's in our crappy 1200-1800 DA. With your significant bump in power (spray) the fluid becomes even more important.

IIRC, subfloor ran 1.5 quarts over with his ~600 HP 427.

dicky

Thanks for the info guys. David, seeing how your car reacted at 1st shows we seem to have a similar issue. All the info I getting from everyone seems to point to the converter which I thought but I want to make sure I'm not missing something.

Hoxxoh, I'll probably try that, I just assumed if I didn't have enough it would launch goofy. I had that problem before, it was costing me about a tenth just in the 60'. Now the car launches great since I put the extra quart back in.

dennis50nj

I would get a new yank PA converter, I have never tried at the track, but on the initial tuning i would estimate a full second gain in the 1/4 with a 100 shot

dicky

That sounds nice! That's my goal is to shave about 1 second off my et, I'd love to see that 9.99 or better on the 150 shot. Right now I'm thinking about getting an FTI triple disc but I'll check the yank PA out too.

dennis50nj

im just guessing would more line pressure help or a better trans tune for the extra power

dicky

I have no idea, I'm not tuner at all haha and don't know much about transmissions. I guess I could do some reading and look at my tune, that'd be nice if it was something simple like that.

dennis50nj

ask Christopher Subfloor he certainly would know

dicky

I had the same idea, I sent him a pm last night asking about that. He'll probably be able to give me some kind of idea.