drperformance

iTrader: (5)

Today was my first time running in a timed event, I normally run flashlight drags 1/8 mile. But today I took four 1/4 mile passes.

1st pass (motor):
driver front of car came off the ground: KYB AGX rear shocks set at left rear: 4 right rear:4
-.2154 reaction
2.2368 60 foot
5.5776 330 foot
8.3620 1/8 mile
10.7544 1000 foot
12.7675 1/4 mile @112.14 mph

2nd pass (progresive controlled nitrous 1st, 2nd and 3rd gears: 200 shot rpm based, start value of 45% @ 3600rpm)
car came up level: KYB AGX rear shocks set at left rear: 4 right rear:6
.5508 reaction
1.6553 60 foot
4.8778 330 foot
7.5869 1/8 mile
9.870 1000 foot
11.7879 1/4 mile @117.83 mph

3rd pass (progresive controlled nitrous 1st, 2nd and 3rd gears: 200 shot rpm based, start value of 45% @ 3600rpm)
car came up level: KYB AGX rear shocks set at left rear: 4 right rear:6
-.1097 reaction
1.6565 60 foot
4.9052 330 foot
7.6397 1/8 mile
9.9689 1000 foot
11.9192 1/4 mile @116.13 mph

4th pass (progresive controlled nitrous 2nd and 3rd gears: 200 shot rpm based, start value of 100% @ 3600rpm)
driver front of car came off the ground straight nailing the throttle off the line, no spin: KYB AGX rear shocks set at left rear: 4 right rear:6
.6862 reaction
1.6177 60 foot
4.8970 330 foot
7.5542 1/8 mile
9.8273 1000 foot
11.7560 1/4 mile @116.31 mph

I have my torque arm set around -3 or 4 negative, and adjustable front coilovers. How can I get more out of this set up? I am running 275/50/15 Mickey Thompson street radials that are at are worn to the wear bars, but still have life. As you can see my last run was the fastest spraying 100% in 2nd and 3rd only and nailing the trottle off the line. I think next time I will try to spray starting at 75% or so 1st through 3rd. What would everyone suggest? I am new to 1/4 mile, should I adjust the rear shocks more?

Any ideas are appriciated, thanks

Should I go to time based progressively controlled nitrous instead of rpm based wich cycles trough each gear and acks like a turbo?

JesasaurusRex

iTrader: (3)

why not spray it right out of the hole?

AlkyIROC

You're not making enough NA power or have enough power adder to need a progressive controller.

joeblue83

iTrader: (8)

What really kills me in races is my reaction time. For some reason I can't get below a .200 or better. Looks like your in the same boat

drperformance

iTrader: (5)

I dynoed at 375 rwhp and 380 rwtq with out the 200 shot of nitrous. So everyone thinks that I should spray everything right out of the hole. And I am running Mickey thompson street drag radials which seem to hook awsome at the track.

I am thinking of switching to some et streets. But the 26x10.5x15 only have a tread width of 8.3". while my drag radials are 275/50/15 and have a tread width of 10.2". Will the narrower ETs help or should I stick with the radials?

AlkyIROC

If you were making 600+NA with a 300+ shot, I'd recommend a progressive controller.

You're making less than 600 total. If you blow the tires off the line from too much torque, use the controller to have it come on about .3 off the line and have it stay on all the way down the track.

irok2fast4u

listen to stephan 87 iroc, he has one of the faster cars here and links to some of the runs. nothing better than real world knowledge/expirience

drperformance

iTrader: (5)

Stephen,

I am currently running my controlller in the rpm mode so the nitrous kicks in at a given rpm (3600) in each gear and builds to the final percentage at 50 rpm less then the shift point. Then it starts all over again in the next gear (acts like a turbo). I could keep it configued like this which is less strain on the shifting of the tranny and put the spray percentages at 100% in all gears. Or if I had to delay it .3 out of the hole like you said, I would have to set it up in time based mode and it will just spray from the time I am at 100% throttle and spray till I got off it at the end of the track. What would you recomend? Thanks

5678TA

just curious, how much does your car weigh?? seems like something's not right..

if you and i raced, you would take me about half a car out of the hole then i would pull a car length around you before the 1/8 and hold you there for a win.. and i'll be on nuts only..

and by the time i'm out of the 60ft, you'd be already spraying in second.. we both have the same back half split.. but from 60ft to 1/8 i'd be .2 faster..

EDIT: i see why its not giving the full 200 shot
another thing i noticed.. how much real hp increase is your "200 shot" giving you?? if your motor pass 60ft'd better, you could have trapped at close to 114.. based on a 3500lbs estimate, from your baseline 112mph to your best 117.8 mph is only 60rwhp gain from nitrous.. i've never used nitrous nor will ever use it but it doesnt seem right even if you only spray 2nd and 3rd..

drperformance

iTrader: (5)

I have know idea? It is a full interior car, all electronics, subframconnectors, glass t tops, and a 8 point roll cage. My guess 3300-3600 lbs?

5678TA

next time you go, slam it with the full 200.. oh, btw, if you 60ft great, you should run around 11.90-12.10 on motor and high 10's with the full 200 shot..

i would put you at about 3400-3500 lbs.. i have the a similar car minus the interior and electronics.. and i'm around 3000-3100

AlkyIROC

You don't need it rpm controlled. Spray it out of the hole and have it keep spraying until you let off the throttle. You're nowhere near using the full potential of what you have.

NOS builds torque. Spraying it at 3500 rpm, you're out of the torque curve.

DIGGLER

iTrader: (1)

if your LT1 is a built 383, i would hit it with a 200 right off the line and see how it does. if it spins, use your progressive to back it off some on the initial hit and quickly ramp it all back in after .2 seconds or whatever.
i wouldnt spray any lower than 2500ish personally. people that do usually scatter their intake manifolds all over the track.

drperformance

iTrader: (5)

Now I am getting it. Stephen my convertor is an edge racing and stalls at 3300rpm, what would you recoment my start rpm for the spray?

Thanks guys!!

I just looked at my nitrous controller program and in timed mode it still has an rpm cut off should I still set it about 50 rpm less them where I shift at to put less of a hit on the tranny? Or should I set it higher and spray straight through the shifts. The tranny is a 4L60E that I built with a Probuilt Elite kit that should handle 750 horses or more, and I cryoed the output shaft.

DIGGLER

iTrader: (1)

if the trans will really handle that, have the nitrous come on at 3,000rpms with a wide open throttle switch also for safety. (your progressive might do this) spray the full 200 through the shifts. cut the nitrous 50rpms or so before the rev limiter.
thats a good starting point i would say.

JesasaurusRex

iTrader: (3)

if u have a window switch set it at 2500 low, if u don't foot brake it up to whatever itll stall and leave like that. (im assuming u don't have a brake) Spraying from 0-1320 ft. If that thing spins you need to look over your suspension cuz it should have absolutely no trouble hooking that thing up on a true 10.5 tire out of the hole. As for radials vs slicks. While there may be some radials going faster slicks are WAY less finicky about having everything dialed in right so unless a class requires it id get a slick over a radial any day of the week.

AlkyIROC

You should always use a WOT switch with NOS. NOS will only activate when the throttle is at WOT. As soon as you lift a little bit, the NOS shuts off.

Unless you're launching with a transbrake, you won't be sitting on the line at WOT waiting for the lights. With a transbrake, you use another switch that will only allow the NOS to work when at WOT and the transbrake releases.

I have NOS in my 454SS pickup truck. 2 switches. One to arm it and a WOT switch. Turn on the arm switch and stage. Bring the rpms up to a launch rpm. As soon as I launch, the throttle goes to WOT, the NOS activates and stays activated until I let off the throttle at the finish line.

4600 pound truck on street tires runs 15.0 NA and has run as quick as 13.28 with about a 135HP shot of NOS.

At no time should the NOS be activated if the throttle is in any position other than WOT.

JesasaurusRex

iTrader: (3)

most definitely always use a WOT switch, i'm just telling him he doesn't NEED a window switch if he plays it smart. I wouldn't leave off idle if i didn't have a window switch that's just me. But he can half throttle footbrake it to whatever it'll stall and then punch it and should be fine with out a window switch.

drperformance

iTrader: (5)

With my FJO nitrous controller I can eliminate the rpm signal or window switch and strictly run on time based. Like you said I have an activation switch to arm the system and then a wide open throttle switch to trigger it. So t it would be easier I could just run 100% nitrous off the line at wide open throttle and delay it as needed.

If I keep the window switch activated I can shut the nitrous off just before I shift. But now that I talked to you guys I will probibly just spray through the shifts.

One thing that I am still not sure about. If my convertor is a 3300 why would I want to start the spray below 3300 rpm if I program the window switch.

I guess it would be easiest to just straight run time based with out the window switch at 100% nitrous.

JesasaurusRex

iTrader: (3)

the window switch is to make sure the engine speed is above a certain rpm so you don't have a nitrous back fire. just another safety precaution like a wot switch and a fpss.

AlkyIROC

If your converter is 3300, you'll never be below that at WOT all the way down the track. As soon as you launch, the converter will flash and stay above 3300 all the way down the track until you lift at the finish.

About the only thing a window switch would do is if you left at an idle. Going to WOT, the converter would flash and the NOS wouldn't be activated in the brief instant until the converter was at full stall. If you don't use a window switch, you'll be at and above full stall instantly when the NOS hits anyway.

As I've already mentioned, you don't need a progressive controller for your power levels. Just use an arm and WOT switch. You only need a progressive controller if you're dumping in huge amounts of NOS or multiple stages. If you want to use the controller, have it ramp in the shot right off the line and it should be 100% about .5 off the line just to lessen the amount of torque to get the car moving and not blow the tires off. I don't think you're at the power levels where you need to.

You have no reason to use a window switch with the NOS. With an automatic, there's no reason to turn the NOS off during a shift. A manual transmission using a clutch to shift might use a window switch as there's a brief instant when the engine is uncoupled from the transmission when shifting with or without the clutch. If with a clutch and the throttle is released to shift, a WOT switch will automatically turn off the NOS anyway.

dragracing_diva

Well the nitrous issue has been beaten up pretty well so guess I will try to help with the reaction time... Count your lights. I launch when the second yellow comes on - I'm foot braking it because of an issue with the line lock... I can consistently be .01 to .08 this way. If you leave on a transbrake then probably when the third light comes on - find out where your time is the best and ALWAYS count the lights the same way. A wise racer once told me if you don't red light you aren't trying... Good luck.

AlkyIROC

Reaction time won't change his ET. He can sit there for 10 seconds after the green comes on and run the same ET/MPH.

Reaction time is the time difference between when the green light comes on and when the tires break the starting beam. Once the starting beam is broken, the ET timer starts.

Yes his reaction times are all over the place but he's trying to find out how to run faster.

Your car must be extremely slow to react if you're launching off the second yellow. You always launch off the third yellow.

Don't even look at the other lights. Concentrate on the last yellow and only the last yellow. As soon as you see it come on, go. If you try to time it by watching the other lights, you'll get terrible lights. Humans are poor timing devices. Just watch for when the last yellow comes on.

I use a delay box with a transbrake which is even easier. I simply watch for the first yellow and release the transbrake button as soon as it comes on then wait for the delay box to release the transbrake. If I react too fast and red light, I add delay next time so I can't red light. If I get a bad light, I was asleep and didn't react fast enough.

dragracing_diva

I don't think I've ever been to a race where reaction times didn't matter but hey what do I know... and my car isn't slow - it's having issues and like any good racer I make adjustments to how I drive it to accomodate for that... but then again... If we all could launch on the same light everytime we wouldn't have holeshot wins... But what do I know...

I'm out of this and since you're the moderator I will leave you to your territory but I must tell you it's pretty rude to assume something about someone else when you have no facts to base your opinion on. He asked for help on improving - and unless I can't read I'm pretty sure his reaction times were posted with his data. Sorry I intruded on your turf.

AlkyIROC

In a "race", reaction time matters but reaction time doesn't change your ET.

drperformance

iTrader: (5)

Ya, reaction time realy is not a concern for me at this point, it was my first time starting from a tree. But I am hoping to get this car into or close to 10s with its current set up. And I think that with everyones input I am well on my way.