Went to KCIR last night - made four nitrous passes

[grey99max]

I did get there - made four passes to begin testing the car - here are the details and I would appreciate comments. Some things don't make sense to me, like the first 1/8 mile times... Shifts were hard and precise - a cough from hitting fuel cut at each shift.

#1 - 23/12/15 Hoosier track tires mounted. Sprayed 50-shot only, from launch. Tranny shifter set to 6400 RPM - N2O spray limiter set to 3,000-6400.

R/T .160
60' 2.223
330 5.983
1/8 9.013
MPH 80.76
1000 11.668

1/4 13.876
MPH 102.41

#2 - Hoosiers still mounted. Sprayed 50-shot in first gear, total 125-shot in 2nd and 3rd gears. All limiters set as above. Car drifted around in second and third gear. Hoosiers are out.

R/T .044
60' 2.205
330 5.926
1/8 8.856
MPH 83.90
1000 11.366

1/4 13.456
MPH 110.17

#3 - mounted 23/8.5/15 M&H slicks at 20psi instead. Lowered N2O limiter to 2900. Sprayed both stages in all gears. Tire spin in 1st and 2nd gears.

R/T .396
60' 2.189
330 5.816
1/8 8.700
MPH 84.88
1000 11.180

1/4 13.254
MPH 110.82

#4 - still with M&H slicks. Lowered N2O lower limit to 2800 and tried to get into both stages immediately. Tire spin 1st and 2nd gears

R/T .116
60' 2.130
330 5.765
1/8 8.658
MPH 84.81
1000 11.137

1/4 13.209
MPH 110.87

The car runs strong and is consistent - I feel I have traction problems, and I want to raise the nitrous to 75-shot plus 75-shot next time out. That should give me a good feel for what to do next. I may order the M&H 26/8.5/15 slicks, or the 26/10/15 version - don't know yet....

[one_fast_max]

grey glad to see you got to make it out there!!

the times definitly aren't what i was expecting as i'm sure you are thinking too. i figured your slicks would hook better than that! track prep not the best that night? the traps are definatly good for 12's though!! good runs none the less!! what did you run 1/8th mile with your 3.0??

time for bigger slicks!! haha

edit:...found your old time slip. i figure good traction will get you equal or better than 8.3....but you made the 3.5 to breathe..3.0 was better for more grunt off the line you think? ..think that might be why the 1/8 isn't so fast? your hauling in the 1/4 though

[kzoosho]

Damn you trapped 4mph more than me but i ran a 13.0. You have 12's there trust me.

[grey99max]

Originally Posted by kzoosho

Damn you trapped 4mph more than me but i ran a 13.0. You have 12's there trust me.

I think so, but it's gonna take some tweaks to make it happen.

One thing that really struck me was that the last three passes had nearly identical trap MPH - but ET was progressively quicker.


The first 1/8 mile was slower than it should be - I suspect the nitrous wasn't kicking in early enough because there is some delay in the circuits - that will take some work and logging on the PLX wideband to see what's happening. Nitrous timing, nitrous amounts, slicks - all need a closer look. Actual track time is very important!

[accordingtou]

Traction=12 sec slip

[grey99max]

Originally Posted by accordingtou

Traction=12 sec slip

So what's the best choice of M&Hs to "get some"?

24/8.5/15, 26/8.5/15, 26/10/15 or 26/12/15 ??? I'm thinking the 26/10/15 tires feel about right...

[SonicDust187]

20 psi is too high for slicks. And I think you may need taller slicks. Try dropping the pressure to 15-16psi and work your way down till the 60 foot doesn't improve.

[Jime]

I wouldn't go to taller slicks yet, drop the pressure like SonicDust suggests. I run mine between 9-12 psi.

[t6378tp]

^ like stated above 20psi is too much, plus if I remember correctly you are using roadracing slicks which are a harder compund than normally used for drag racing.

I think the size is fine but 26's will hold alittle more power off the line, a nice burnout with lower tire psi and do not bring in the 2nd stage till the top of 1st

yeah get those 60ft's down and your good to go, slicks should = sub 2.060fts

[Nealoc187]

20psi in the slicks will do that to you. That's twice as much pressure as you want. Drop it to like 13psi next time and then each pass take a half a PSI out until your traps start to go down or your ET stops dropping. You'll end up between 9 and 12 like jime said. I always found 11psi to be my sweet spot.

[grey99max]

Originally Posted by Nealoc187

20psi in the slicks will do that to you. That's twice as much pressure as you want. Drop it to like 13psi next time and then each pass take a half a PSI out until your traps start to go down or your ET stops dropping. You'll end up between 9 and 12 like jime said. I always found 11psi to be my sweet spot.

I ran the first two passes with the 12" track Hoosiers - because I never used them before - at 20 psi - then decided to ditch them and mount the M&Hs. They were at 20 psi as well. The Hoosiers actually worked pretty well - but would be better on a NA car. Nitrous makes funny bumps in your torque curve, you know.

Since the 10PM curfew was coming up, I just played with the nitrous window and sprayed both stages in first gear. It got a little quicker, but I didn't have time to try lower tire pressures. I never had much luck with even 15psi - the slicks wrap up around the wheel and steer funny.

Track prep wasn't anything special - and the staging area was at 115*F at 6PM. It did cool later - after 8PM, but still very humid. In first gear you could feel the car drift some, and there was a small mountain of tire rubber in the launch area. They didn't scrape it off all night - or spray VHT.

Before I think about tires, I gotta pull the PLX data logs and see (besides the A/F) what RPM I was at going through the traps. I think I have two passes logged.

I think the collective mind here is correct - lower the tire pressure and measure what happens. Plus I'll bump the shot-levels up a notch or two - maybe 150 combined, maybe 175-shot. I just pulled the front plugs and they looked identical to the dyno photos - all good.

Yesterday was a long and expensive day, but well worth it - the car screams through the traps now. The Land Shark is getting some teeth!

[accordingtou]

Originally Posted by grey99max

So what's the best choice of M&Hs to "get some"?

24/8.5/15, 26/8.5/15, 26/10/15 or 26/12/15 ??? I'm thinking the 26/10/15 tires feel about right...

Since I have never ran with slicks.....
I honestly would be taking a wild guess

[QNO_A32]

good stuff and yeah slicks should = < 2.0 60ft times.....
in for the 12 second slip......VIDEO????????

[grey99max]

Originally Posted by QNO_A32

good stuff and yeah slicks should = < 2.0 60ft times.....
in for the 12 second slip......VIDEO????????

no pix, no videos.... no time.

[grey99max]

Here are the graphs from the first two runs - lots of 2nd gear wheelspin in the second graph..
You can see the Shift_Fast_3 shifting 1-2 and 2-3 clearly - both the RPM and AF graph twitch hard.

This is the 50-shot pass:



This was 50-shot in first, 125-shot in 2nd and 3rd gears. With the 12-inch Hoosiers, spinning lots in 2nd gear - look at the graph. Trap RPM was 6329 - kinda close to fuel cut. A/F was good at 125-shot.



I think I may try a larger slick....

[Dave B]

Hey Grey-

I'm glad to see you're still running the Max. The car is running damn good, especially for the warmer temps. I'm heading to KCIR this Wednesday for some runs because I want to see just how much heat influences my VQ35 and I want to try some new launch techniques.

[one_fast_max]

grey, from personal experience i don't think you need new slicks. just run closer to 11ish psi. and do a good burnout through the water box. i say this because last night my slicks made a world a difference from being 11psi or 20 psi, with a good burnout or not.

[fourthchirpin]

20psi on slicks.... are a bit much. i say drop the tire pressure. I think u can crack 12's ez.

[grey99max]

Originally Posted by Dave B

Hey Grey-

I'm glad to see you're still running the Max. The car is running damn good, especially for the warmer temps. I'm heading to KCIR this Wednesday for some runs because I want to see just how much heat influences my VQ35 and I want to try some new launch techniques.

Good - if you can figure how to launch the Shark, I'll buy the beer - especially LandShark Lager !!!

I just got back from KCIR - at the Sunday Import Shootout, better known as the Honda Lovefest. Only saw three Nissans there (350Z, 240SX, 300ZXTT), and well they were either slow or broken. Bummer...

[grey99max]

Originally Posted by one_fast_max

grey, from personal experience i don't think you need new slicks. just run closer to 11ish psi. and do a good burnout through the water box. i say this because last night my slicks made a world a difference from being 11psi or 20 psi, with a good burnout or not.

You're just saying that so you don't hurt my feelings, since your car is now pretty dang quick....

I took photos of a bunch of 10-sec turbo cars at KCIR today, and most had MT or M&H slicks with about 3 psi. I'm gonna post the photos' links when they finish uploading.

By the way, congrats - I saw your thread from earlier. Pretty darn good job, bud..

[grey99max]

Saw these slicks today at KCIR - seems like lower pressures are the way to go. Oh - these are all 10-sec cars today.





http://i48.photobucket.com/albums/f2...8/DSCN0432.jpg

http://i48.photobucket.com/albums/f2...8/DSCN0433.jpg

http://i48.photobucket.com/albums/f2...8/DSCN0435.jpg

http://i48.photobucket.com/albums/f2...8/DSCN0427.jpg

Plus some Lambo doors for comic relief..

http://i48.photobucket.com/albums/f2...8/DSCN0425.jpg

Also ran into my buddy with the 11-sec 2.4 L AWD Eagle talon - he's now dynoing 606 WHP on a AWD dyno, which are rare around here. He was carefully tuning the car today, so nothing outstanding, but I ran against him when he did a 11.27 ET. I keep that slip in the garage. The other RWD EagleTalon there today has about 750WHP, he said. Busy day - 10sec Hondas and 9-sec bikes. Whew..