Carter01

iTrader: (11)

Ok, this might should go in the dyno forum but I believe that more people that race would care to hear this than people who just care about dyno numbers. About two years ago to the date I had my cam and ls6 intake installed and had a dyno tune. At that time my car made 391 rwhp and 362 rwt, this was through high flow cats and the stock 10bolt with 410 gears and my stock injectors were hitting 100% duty cycle. So after a few months i started doing the normal upgrades like Moser 9inch, big alum DS and deleted the cats etc.. Now fast forward two years later I decided to swap to a TH400 with a 4500 stall. I made the swap and went back to the track and ran almost identical times, my best 6sp time was 11.75 at 118 in great weather, my new best th400 times are 11.84 at 115 with not so good weather. Ok, so I am not totally excited with the swap but not disappointed either. Granted I still had the same tune in the car as I did for the 6sp. This year I decided to run N20 so I went ahead and upgraded my injectors to stock 28s, Racetronix 255 and Hotwire kit. This made the car go way rich so I took it back for a retune yesterday. To my surprise the car made 384rwhp cutout closed and 390 rwhp open, I was totally shocked! Maybe my car has been starving for fuel for two years and needed the fuel upgrade to really make the power???

Variables from TY vs 2 Years ago: Same tuner, Same dyno, Very similar weather, actually a little cooler the first time, Same rims and tires, Same tuning software etc.. Basically everything was the same except for: No cats now, Added a Moser 9 with 410s, Th400 with 4500 stall.

I really was thought I might make between 350 to 370, I never would have dreamed I would be back at my 6sp numbers. I can't wait to go to the track and see if she is any faster since the retune!

SlickVert

iTrader: (5)

What was the numbers on the first pull prior to your tuner retuning?

Carter01

iTrader: (11)

I think like 370, BUT that is not a real world number due to him making the injector table swap prior to making the first pull. I really wish I had dynoed it just like it sat after the tranny swap and before the injector swap. That would have been a better comparison but it wasn't feasible at the time.

dutinsss

iTrader: (2)

that is very surprising. i would have expected your ET to drop with the trans swap though.

94Z28rag

iTrader: (10)

I wouldn't. Correct it for Density Altitude for each of the runs and I bet the TH400 pass is faster in the end. You'll always lose MPH, but gain consistency and ET when all is ironed out.

SPEEDYws6

iTrader: (9)

Sounds like you can drive a stick car.

Villain281H

iTrader: (5)

I'd say rwhp will drop with a manual to auto swap almost every time, ditto for the 9 inch versus 10 bolt swap. But this is the reason why a dyno is a tuning tool. We've swapped to looser converters and seen a 10-15 rwhp loss on the dyno but the car runs 2-3 tenths quicker due to being in the powerband.

The TH400 should get you to a much better ET, but as mentioned the weather isn't the best right now. SGMP in about 4-6 months will do the trick!

Carter01

iTrader: (11)

You're right, generally around mid Nov we will get a good cold spell that nets some good ets. I'm going to go try it again this upcoming sat because there doing a night race, like 5p-12a. Maybe I can get some decent air around 10 pm or so. Even if it isn't faster than before I at least now know where I'm at so I can tell what future mods do for the car.

Carter01

iTrader: (11)

Thanks, I've been told I do ok.

Carter01

iTrader: (11)

Here is a copy of the graph, 391 was the 6sp and 384 the auto, not sure where the 390 graph is, will look for it.

BLK02WS6

iTrader: (2)

I would say a couple things... taking off the cats probably made up some of the power lost by the rear and trans... secondly, I would say your convertor is much tighter than a 4500 stall - that would account for the surprising power numbers and the lousy 60ft. You should be very low 1.5's with a 4500 stall. What kind of convertor is it? Did you buy it new?

Carter01

iTrader: (11)

FTI Converter, Yes I bought it new. Another reason reason why I want to go try it out again after the retune. I think that the tune was pretty far off after the auto swap.

One more thing, when you said "is much tighter than a 4500 stall" are you saying that it won't stall up to 4500? Not really sure what you meant. The reason I say that is the tach shows 45 and that's all I had to go by, however I don't trust the stock tach. I will try to datalog it and see what it shows.

Old Geezer

iTrader: (3)

I'd try the N2O B4 I changed converters....

Carter01

iTrader: (11)

Oh yes, that is happening in the near future

BLK02WS6

iTrader: (2)

The true stall of the convertor (which is not always the advertised stall) can be seen by loggin at the track - when you launch the car, the RPM that the engine flashes to before it starts to move is the true stall...

Like Old Geezer said - if you are going to spray it, don't change the convertor till you do...

My nitrous convertor would give me 1.62 to 1.64 on the motor... and 1.30 to 1.32 on the jug. You'll have to try it and see how it does.

Carter01

iTrader: (11)

Ok, that makes sense. Greg built it to fit my car and I told him upfront I was going to run a 150 shot minimum. He tried his best to build the best of both worlds for me so that could be why my 60 is a little lazy. I hope to try it on the jug very soon! Thanks

BlackScreaminMachine

iTrader: (17)

A converter set up for NA hits a whole different converter then a Nitrous one would be, like said put the bottle to it and do some hits off the line and make sure it is leaving correct.

Villain281H

iTrader: (5)

Kinda doubt it. Summertime air typically brings humidity in as day changes to night, so although the temp drops, the air quality doesn't always improve (water quantity/water grains go up).

Derek

Carter01

iTrader: (11)

Ok, I went back to SGMP tonight and it was so humid your clothes would be wet with water, not sweat in like 10minutes. I checked the da and it was showing 2100. I made three passes and it went like this:

pass 1
60 ft 1.70
1/8 7.65
1/4 11.98 @ 114 (air pressure too high)

pass 2
60ft 1.62
1/8 7.59
1/4 11.94 @ 114 (hooked good but jumped to the left, fixed it by adding one click compression to right rear shock)

pass 3
60ft 1.69 (spun on the hit, track was going away pretty bad later into the night)
1/8 7.59
1/4 11.91 @ 114

I did the DA correction and it had me at an 11.62 at 117. I truly believe the car in some good weather would go 11.7 at 115-116 range. I now know where I'm at since the retune so it's time for the spray now!!!

One more interesting thing, I originally thought that my converter was a 4600 stall because that's what the tack would go to on the TB. Well the tach was wrong, did some data logging tonight and my stall goes to 4300-4340. I now believe this stall is going to hit hard on the gas, I can't wait unitl the 31st, that's our next T&T.

xtreme2001

i hae a th 400 with a tci ssf 3400 to 3800 with 3.73's in the rear and my car 60 ft's 1.52.....of course i have a 383 carb sbc in a 94 z/28