Questions regarding nitrous activation point & launching my combo.

[RUQWKNF]

Hello everyone.
I've recently installed an NX plate kit and plan on spaying a 150 shot with my combo I've been slowly working on for the past year.

Current mods:
2011 Automatic, stock trans, stock converter, stock 3.15 gears, stock suspension, stock headers, Jegs cat delete pipes, stock H-pipe, stock OTA pipes, GT500 axle back. JLT plastic CAI, JLT pass side oil separator, MSD RPM window switch and WOT microswitch on the gas pedal. N2O purge kit and bottle heater. M&H Racemaster 275/45-18 drag radials, front swaybar completely removed and trunk empty except for the bottle. And the most important piece of the puzzle, BBR 150 Nitrous 93 octane tune.

I've been told and read others who spray at 3000-3200 rpms and others who spray from the WOT hit down low. But in all my searching on here, I couldn't find any definitive answers to my questions.
My three questions are,


How many of you are spraying WOT from the hit without any problems, vs waiting for 3000-3200 RPM?



I know the most important aspect in getting the best ET, starts with the 60ft. I also know that I will have my hands full hooking this tire spraying it out of the hole. This combo before the nitrous install does have a slight bog when flat footing and the converter flashes. My converter feels like it was made on a Monday and is really tight. Ughh.:rollseyes
My next question is this,


If I spray off the line, will the nitrous torque hit overcome this dead spot and smoothly accelerate?



That is the only thing that concerns me as I have full faith in BBR's tune.
And my last question is this.


Is there anyone who foot brakes and e-brakes together when launching to get the highest launch RPM possible on a stock converter?



With this converter being so tight, that's the only thing I can think of that might help, vs the expensive route of gears, aluminum driveshaft and converter.


I'm probably over thinking this too much and shouldn't worry and just spray it. I've been drag racing domestic turbo cars for so long and never had nitrous on a rwd car with such a tight converter. I always had a good converter and a transbrake on my turbo cars. It honestly feels like a 1900 flash stall. Gahhh. It needs a converter bad. Anywho, I just wanted to get some feedback from all of you automatic guys out there who are using this kit and or spraying off the line. I've built this combo with the whole intentions of keeping it simple and basic. Something that anyone can duplicate. Eventually my plans include an aluminum driveshaft, converter, skinnies and bias ply ET Streets on Weld S77B's.
I hope to make it to the track this coming weekend to get some datalogs for Steve and try to better my 12.39 @ 113 best. I will also be taking all the unnecessary junk out of the car on race day, you know, glove box contents, center console and cup holder change, all the crap in the back seat, etc, etc. Cause, ounces = pounds. :-D And just for the record, here is what a 275/45R-18 M&H Racemaster drag radial looks like installed on 18x8 Charcoal AMR wheels.

I went with the 8" wheel to maximize the sidewall. When the tire pressure is lowered down to 18psi, the contact patch is perfect out to the edge of the tire. These pics were just after taking them out of the box/install with too much air in them. The car definitely has traction now on motor.

Your feedback is welcome and thanks in advance.

Patrick

 

[CharlieR]

From my very first nitrous kit I was told "do not spray below 2500 rpm, the cylinder pressures become too much and engine damage will result". That was in 1988 on a 100 shot NOS AFB carb plate. It was in the instructions on the next few kits I purchased. It didn't say don't spray below 2500 for more than .3 seconds it said don't do it. I know a lot of guys are using the n2o hit to flash their converters but I wouldn't risk it. I understand a converter is a big expense but so is a short block should you bend/break a rod. . BTW my window is usually set to 3500 minimum(3800 converter).

Log the dead spot and see what's causing it. If you decide to spray off the line you won't notice any dead spots unless it goes really dead.

I've been a 1.46 best and mostly low 1.5 60 ft times with 265/40/18 Mickey Thompson ET Street Radial II's so I think your M&H's will work for you just fine no matter how you leave. . Had 0 luck hooking 305/45/18 NT05r's for whatever reason. :shrug:

 

[RUQWKNF]

Thanks CharlieR for the insight. I'm definitely sold on getting a converter, just gonna take awhile.
I am going to try to footbrake as much as possible as well as stab it just off idle with the activation point set at 3000 to see if there is a difference.
That's also good to hear about the tires. I have heard and witnessed a few local guys with those exact Nittos, having problems hooking a 100 shot even after a good burnout. One things for sure, these M&H's hook on the street.

I will update this with my results as I'm sure there are a lot of others out there with the same questions.
Any other feed back is welcome.

Patrick

 

[CharlieR]

Thanks CharlieR for the insight. I'm definitely sold on getting a converter, just gonna take awhile.
I am going to try to footbrake as much as possible as well as stab it just off idle with the activation point set at 3000 to see if there is a difference.
That's also good to hear about the tires. I have heard and witnessed a few local guys with those exact Nittos, having problems hooking a 100 shot even after a good burnout. One things for sure, these M&H's hook on the street.

I will update this with my results as I'm sure there are a lot of others out there with the same questions.
Any other feed back is welcome.

Patrick

Yes My nittos SUCKED when spraying. Tried pressures from 12 to 30, big and tiny burnouts. I hate them. The Mickeys were 2.5 inches shorter, 1.75 inches narrower and worked better. I think 3000 will be a good safe compromise until you get a converter.

 

[Eric@jpc]

i would turn it on asap

heres the thing with nitrous, they dont want you spraying that low RPM when there is alot of load on the engine. In 1st gear there is little to no load.

I would hit it as soon as the green light comes on and hope you have enough suspension to hold it

 

[NitrousExpress]

There is no problem hitting nitrous off the line to get out of the hole. This is where an RPM window switch comes in handy, just set it for 2800-3000 RPM's, and let it eat. You want to avoid bogging the motor and spraying nitrous, with a window switch though, you won't have to worry about that.

-Garrett

 

[Tuffnuts23]

i would turn it on asap

heres the thing with nitrous, they dont want you spraying that low RPM when there is alot of load on the engine. In 1st gear there is little to no load.

I would hit it as soon as the green light comes on and hope you have enough suspension to hold it

I always assumed it was bad to spray at low RPM regardless. I usually have my 2 step set between 4-5k, and then I set my window switch 500rpm above my 2 step. I was worried about spraying the motor for those few seconds before I dump the clutch. Can I safely get away with setting my 2 step and window switch to the same rpm?

 

[SteveG@Lethal]

I spray mine off the hit. I launch at 1500rpms on the stock converter for over a year. This was with the REAPER and plate kit. Let her eat!

 

[NitrousExpress]

I always assumed it was bad to spray at low RPM regardless. I usually have my 2 step set between 4-5k, and then I set my window switch 500rpm above my 2 step. I was worried about spraying the motor for those few seconds before I dump the clutch. Can I safely get away with setting my 2 step and window switch to the same rpm?

I would set mine higher than the 2 step, just so that way you aren't spraying on the 2 step.

-Garrett