Mazda Rotary Club

Hi guys as per the title I want to work out how to extract the best drag times from my car in its current spec.

I know some of you are pretty hot when it comes to technique on the strip so some feedback on my setup (tyre pressures, susp. settings), times and technique (launch, gears) would be appreciated.

I went down to santa pod last weekend and managed to get three runs in which wasn\'t ideal as there was an hour or so gap between each run. I was trying to better the times I achieved at the PTM show last May as I\'ve since added an Apexi and got the car mapped at REWORX.

Mods to the car are as follows:
UK spec FD with-
JDM downpipe,
high-flow sports cat and aftermarket cat-back
tein super-streets
265mm wide rears (kumho supra ecstas) - 32psi
Atmospheric bov
Apexi power fc mapped to 323.7fwhp (268.6hp atw) @ 0.9 bar

at the wheels
(http://photos-h.ll.facebook.com/photos-ll-snc1/v2729/57/26/697435386/n697435386_6373719_6321343.jpg)


at the fly
(http://photos-g.ll.facebook.com/photos-ll-snc1/v2729/57/26/697435386/n697435386_6373718_1008640.jpg)


So, last May, running on the stock UK ECU (maybe 250 fwhp with the exhaust?)

my best times were:
60ft - 2.17
1/8 mile - 9.18 @ 77.53
1/4 mile - 14.14 @ 99.82

Last weekend my best was:
60ft - 2.38
1/8 mile 9.14 @ 81.80
1/4 mile 13.82 @ 104.77



So an improvement of 0.32 seconds in the ET but trap speed was up by about 5mph.

Ideally I reckon I should be going for a mid to low 13s run now ( an optimistic gran turismo simulation predicts a 13.04 @ 109 with my power / gear ratios etc.)

basically my launches aren\'t up to much - my 60fts last weekend were letting me down (not as good as last year) but also I ran into problems during the last few seconds of the race too - running out of gear / power in third but not wanting to waste time changing to 4th - two runs I had changing to 4th got me slower times - my best run had me on the limiter in 3rd - what shift strategy should I use? What does everyone else do?

I haven\'t been launching too agressively - revs to 3.5-4K and slip the clutch to avoid wheelspin - should I use the handbrake?

Does my atmospheric BOV lose me time on the gear changes? - An article in Redline this month makes me think it could.

What tyre pressures and damper settings would be best?

Cheers guys

I\'m no expert but i\'ve alway been told let alot of pressure out the rears set the suspension on the back low and soft and high and hard on the front. obviously not to the point it is dangerous. I\'m sure there are people on here that have done quite a bit of playing.

there was an article in Import Tuner recently (can\'t boody find it though now, can i!) where they tested a blow off valve releasing to the atmosphere or pushing back into the intake. they found that releasing back into the intake made a couple more ponies (literally all of two or three) on the dyno and the turbo would spool up a little bit quicker.

Quote from: jackaleks;598401there was an article in Import Tuner recently (can\'t boody find it though now, can i!) where they tested a blow off valve releasing to the atmosphere or pushing back into the intake. they found that releasing back into the intake made a couple more ponies (literally all of two or three) on the dyno and the turbo would spool up a little bit quicker.

Yeah I was thinking this too - not sure if that\'s enough to make a difference on the 1/4 mile but I might try plumbing the standard part back in next time I go to santa pod.

i think youll find that unless you change your gearing your always going to be changing into 4th just before the line. you want soft suspension on the rear so the car squats and harder on the front. ideally some drag tyres would be better to get good 60foot times. the rest is just practice

Quote from: lee mills;598421i think youll find that unless you change your gearing your always going to be changing into 4th just before the line.

What\'s the optimum point to change? 6.5, 7, 7.5, 8K??

I generally change at 8k.
perhaps try launching with more revs to try and get your 60 foot times down. hope youve got a diff brace though or else your running the risk of blowing your diff

after watching your video a few times it seems like its your launch that you need to work on. soften up your rear shocks so it squats more=more grip. only trouble with this is you have more chance of breaking things. its very addictive isnt it:yes

Quote from: declasm;598429What\'s the optimum point to change? 6.5, 7, 7.5, 8K??

Depends where your peak torque is. You want to change gear so drop back into it on a gear change with about 1.5k lost changing gear. If its stock ports then change gear about 7k. Peak torque should be around 5.5k.

Best I ever got was a 13.25 with a bit more power but not overly mental in the launch.

Shaun

Quote from: lee mills;598434its very addictive isnt it:yes

It really is - I was thinking I\'d be happy if I could just get in the 13s at over 100mph - now I\'m thinking it would be nice to get a low 13 - maybe a high 12 (y\'know gallardo territory) - I can imagine it all snow-balling out of control until i\'m racing \'busas like blitzboy!

Cheers for the pointers!

Quote from: shaunwil;598441Peak torque should be around 5.5k

Yeah on the graph (the whp one) I think peak torque is pretty much around 5.5K so I\'ll try changing at 7K next time

Quote from: declasm;598453It really is - I was thinking I\'d be happy if I could just get in the 13s at over 100mph - now I\'m thinking it would be nice to get a low 13 - maybe a high 12 (y\'know gallardo territory) - I can imagine it all snow-balling out of control until i\'m racing \'busas like blitzboy!
 
Cheers for the pointers!

Ive spent a fortune getting the car ready and hopefully this year will be pushing 10,s myself just need to find the optimum setting on my new tein monoflex once the car is back from reworx:Giggle

Yeah - I seem to remember reading about your car in in that performance tuner article and seeing some horrendous amount of money quoted!

Quote from: declasm;598456Yeah - I seem to remember reading about your car in in that performance tuner article and seeing some horrendous amount of money quoted!

lol yep unfortunately its all true. there has been a lot of wasted money along the way but when i reach the 10,s it will all be worth it:Thumbsup!

Good to see you beat the Subbaboo :rollin:rollin:rollin

change at 8k, launch at 5.5k,use the handbrake to preload the drivetrain on the line,get a diff brace,soften the rear shocks, on road tyres u cant go less then 28psi

Quote from: BlitzBoy;598481change at 8k, launch at 5.5k,use the handbrake to preload the drivetrain on the line,get a diff brace,soften the rear shocks, on road tyres u cant go less then 28psi

Straight to the point, nice! :yes

I was up at santa pod at the PTM show today to test out some new techniques. It was pretty hot so I don\'t think my intake temps were ideal. my best run came after leaving the bonnet open for half an hour! Also I had about 50 litres of fuel in the tank!

I found that a burn-out made no difference to my launch and actually my best 60\' was with none at all.

here are all of my times:

13.56 @ 103.92, 60\' 2.10
13.88 @ 103.56, 60\' 2.34
14.03 @ 103.91, 60\' 2.49
14.03 @ 104.30, 60\' 2.36
14.21 @ 106.23, 60\' 2.49 - best ever terminal speed - banging the limiter in 3rd!!
14.21 @ 99.57, 60\' 2.47
14.40 @ 102.90, 60\' 2.49
15.54 @ 100.38, 60\' 3.77 - I started in reverse on this one!

I am absolutely over the moon about my best run - getting a 13.5 was what I felt the car could do and I got my best ever 60\' with that 2.10 - I think I surprised the two 380bhp evos I was racing! I found that changing up around 7.5krpm worked for me and I was launching at 4.5krpm.