Sideways240sx

iTrader: (22)

Ok. so last time @ the track the car went a best of 12.0 @ 116 with a 1.79 60 ft. (no 2 step) almost 90 degrees outside.

Now the car has a 2 step. I threw some 100 in to be safe. It was 75-78 outside. The car 60 ft way better. Consistent 1.71-1.79.(not to bad for a 6 spd)

The car felt like it made no power above 4500 rpm or so. Mph was down 10mph or so from the last outing. But we got consistent 12.4-12.5.

http://www.fquick.com/videos/2_step_burnout/7154

http://www.fquick.com/videos/Mwir_Dr...ng_2_step/7151

Anyways long story short, i need the tune looked at again. I dont think it can be lean. I have a wideband, but the sensor's dont last very long, so i dont know how accurate it is. Could be the knock sensors, but its pulling a bunch of timing or something.


Thought you guys might enjoy the burnouts, and 2 step launches. rest of the vid isn't worth watching.


Any other ideas let me know. Chris

Ps for anyone that doesn't know my car its a 6 maybe 7 psi tune. almost 500 @ the wheels 6 spd. 3.5 gear, 6 spd.

spec_j

iTrader: (3)

gotta get that thing dialed in. It has alot more to go if you are putting down 500hp. Do you tune the car yourself? If so then you need to look at your fuel trim tables, and see if you can smooth out the VE some and maybe add alittle timing. beacuse something isnt right.

Broke EF

We don't currently tune the car ourselves but we are looking into it. The tune was for ~6 PSI, but the valves were floating somewhere around 4-5kRPM. He replaced the valve springs and never went back to the dyno. Since then we changed the WG spring so now boost is ~7-8psi. To be honest I think there has always been an issue, it just got worse with more boost this last time out. The car was never quite what it should be, but there is always next year

Sean

Pro Stock John

iTrader: (34)

Please post the whole time slip, give a rundown on your combo, what tires in back, and your raceweight. Looks like you were racing at Byron.

Broke EF

Well have to wait for Chris for ALL the specifics but I can tell you what I know.
Stock LS1
LS6 intake manifold
Ported stock TB
60lb injectors
homemade truck manifold turbo set up with PTE GT42-76 1.10 A/R
Centerforce dual friction clutch
stock T-56
MWC fab 9 with 3.50 gears
MWC rear drag sway bar
MT ET Street Radial 275/40 R17 tires
Strange drag shocks in the rear
stock rear springs
Thats about all I got right now. Yes it was at byron last sunday.

Sean

ndfrsd6

iTrader: (5)

ok first off get some et drags! the street radials DO NOT LIKE THE 2 STEP ....i'm running a 275/60/15 mt radials and i have a 2 step and the tire cant handel it ,been there done that alot ...it seems only at 3000 it stays hooked and on a 6 spd you need to come out alot harder than 3000 to run fast . in my sig im coming out at 5000 slipping the clutch and running a 1.49 60ft on the 2 step you should be coming out at 6000 or so ....

Broke EF

Traction has yet to be a problem. Settings were about 4300RPM and 5psi boost. Before the two step I dumped it a about 5k and still dead hooked. We haven't gotten these tires to spin on the track yet.

Sean

ndfrsd6

iTrader: (5)

yeah but with that power you should be going 1.50's or better i'm a big dr person but im switching to et drags i'm not happy with 1.50's my car should go 1.40's off the 2 step

Pro Stock John

iTrader: (34)

Need a whole slip and raceweight too. Shift points.

Broke EF

I dont have slips, cant remember race weight, and I shifted ~5500-6000RPM going off the stock tach.

Sean

Pro Stock John

iTrader: (34)

What valve springs?

ndfrsd6

iTrader: (5)

i agree time slips please and setup for valvetrain seems a little low on the shift points ....
also whats your rev limiter set at ?

Broke EF

Z06 yellow springs, I think limiter is at 6500, maybe 6200. I didn't rev it out higher, cause there was no point. I bet if we put it on a dyno the power would just drop after 4800rpm.

Sean

ndfrsd6

iTrader: (5)

thinking and knowing are two diff things ....it seems low 4800 for your power to drop off ,imo i would dyno tune it know exactly where your shift points are power drop off ect....and exactly how much power your making ... maybe its just me but i know everything about my car inside and out ....

Pro Stock John

iTrader: (34)

I would run beefier valve springs for sure, I was shifting mine at 7300 and it wanted even more.

Sideways240sx

iTrader: (22)

As broke ef said. Its yellow ls6 valve springs. tsp push rods, all i did to heads. The springs were freebie brand new, so i had to give them a shot.

The car weighed 3630 with the driver. I can still get more weight out, we didn't do that much.

As broke ef said. the tires are hooking pretty well. 1.71 60 fts i dont feel are to bad for a 6spd car with a 3.50 gear. Yes we can still launch harder, but the car was not mphing @ all. I honestly think its going lean, and pulling all the timing out. I need to find the time slips, i dont know if i have them, or left them at my parents house out by byron.

Im really thinking about picking up hp tuners, going to a sd 2 bar and doing the tune myself. I wll post up more info when i can.

Thanks for all the replies guys, sorry i didn't have all the info up.

Sideways240sx

iTrader: (22)

I found the slips.

60 = 1.71
330 = 5.150
1/8 = 8.009
Mph = 87.14
1000 = 10.448
1/4 = 12.478
mph = 109.78


Last time @ the track we were consistantly 90-92 mph in the 1/8th mile, and 116-118 on the top end. I really want to buy hp tuners so i can data log the runs on my laptop.


Chris

i also forgot to mention the rev limiter is set @ 6200 rpm. I was told by alot of people not to spin it much higher. Maybe when i build a motor i will go to 7.

ndfrsd6

iTrader: (5)

even so with close to 500 rwhp you should be closer to 100 mph in the 8th ...im 500 rwhp and im at 103 average and 6.81 in the 8th ..... your 60ft is fair at 1.7 im cutting low 1.5's 60 ft. and im a 6 speed on a radial ,thats easy to fix though ....come out harder lol....

Broke EF

Have you totaly missed what we think the problem is? If the car is pulling timing over 4K RPM, then its not even close to 500WHP, thats why the times are off. To be techical it only ever actually made 461WHP with power falling off at about 5k RPM with about 5-6psi. The tune past that was a guess, and once the problem was fixed it never went back on, so 500 is a guess.

Sean

ndfrsd6

iTrader: (5)

it just sounds like everything is a guess .... good luck with the tune