Spraying in 5th .. BOOOOM ??? ..
Just cannot get to sleep cause of the horror stories I heard about a backfire that might be occurred when spraying in 5th gear with gear ratio of 3.42

Some say that the 5th is overdrive gear and with 3.42 rear gear ratio the engine is actually spinning slower than the wheels. Which can cause the fuel and N2O to load up in the cylinders and then I will lose my NICE LOVELY $800+ PORTED FAST INTAKE, $250 MAF, Lid, might be the engine or the car itself



Current Suggestions :-
- Not Spraying in 5th !.. while the race ( against a bike ) will required to do that 2nd, 3rd, 4th and 5th ..

- Going with a lower numerical gear in the rear to avoid spraying in 5th .. but I will lose my acceleration N/A

The car is 01 SS M6 with mods in sign ( Bolt-ons ) only plus the below nitrous system
NO 92mm Wet Plate System with C16 in NO Standalone fuel cell
I didn't forget the MUST list ( Progressive Controller, Timing Control, Bottle Heater, FPSS ... ) Also BR7EF and BR8EF are kept in stock in my home

So guys are these only rumors about nitrous from FI guys
or it is real ?? .. and what do you think ?? Last edited by Cold Zero; Jul 14, 2011 at 11:41 AM.
7500 RPM 194.97 MPH
7000 RPM 181.98 MPH
6500 RPM 168.98 MPH
6000 RPM 155.98 MPH
5500 RPM 142.98 MPH
5000 RPM 129.98 MPH
4500 RPM 116.98 MPH
4000 RPM 103.99 MPH
3500 RPM 90.99 MPH
3000 RPM 77.99 MPH
Going by 26" tires, 3.42 gear and .87 trans gearing as long as your over 100 mph I'd say your OK spraying it..... you should be 130mph or better before you shift to 5th.
Alot of stuff to consider when spraying for that long (2nd gear thru 5th) ... #1 would be heat, longer you spray it the more heat you build.
Bottle drop has to be alot also.
7500 RPM 194.97 MPH
7000 RPM 181.98 MPH
6500 RPM 168.98 MPH
6000 RPM 155.98 MPH
5500 RPM 142.98 MPH
5000 RPM 129.98 MPH
4500 RPM 116.98 MPH
4000 RPM 103.99 MPH
3500 RPM 90.99 MPH
3000 RPM 77.99 MPH
Going by 26" tires, 3.42 gear and .87 trans gearing as long as your over 100 mph I'd say your OK spraying it..... you should be 130mph or better before you shift to 5th.
Alot of stuff to consider when spraying for that long (2nd gear thru 5th) ... #1 would be heat, longer you spray it the more heat you build.
Bottle drop has to be alot also.
Don't you think using C16 in standalone will help to eleminate that heat built ?
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I think you should go to a 3.73 or even a 4.10 gears, depending on how long is going to be the race (you need to find the highest acceleration up to 5th gear).
The only problem I see is the duration of the race, You will spray nitrous for too long. Even if you have 2 bottles to avoid nitrous starvation, you will overheat the engine, because nitrous isn't supposed to be used for that long.
Find what works best, spraying 2nd, 3rd and 4th vs 3rd, 4th and 5th
I think if you spray 1st and even 2nd you'll only spin the tires.
How big is the shot? Which tires you're using?
You can try going for a smaller shot to use it for longer, or install a water-meth kit to cool the engine
It's going to be a tough race anyway.
I think you should go to a 3.73 or even a 4.10 gears, depending on how long is going to be the race (you need to find the highest acceleration up to 5th gear).
The only problem I see is the duration of the race, You will spray nitrous for too long. Even if you have 2 bottles to avoid nitrous starvation, you will overheat the engine, because nitrous isn't supposed to be used for that long.
Find what works best, spraying 2nd, 3rd and 4th vs 3rd, 4th and 5th
I think if you spray 1st and even 2nd you'll only spin the tires.
How big is the shot? Which tires you're using?
You can try going for a smaller shot to use it for longer, or install a water-meth kit to cool the engine
It's going to be a tough race anyway.
There is a problem spraying in 5th gear. That is high load being placed on the motor. This will demand a more conservative tune up to keep parts alive.
Nitrous starvation? I take this as pressure drop. This isnt too much of an issue in keeping the motor alive. It will decrease some performance however.
Nitrous can be used for any length of time if setup properly. We have lots of users that use them for Top speed runs, even in the salt flats. It just takes the right parts and tuneup.
Nitrous starvation? I take this as pressure drop. This isnt too much of an issue in keeping the motor alive. It will decrease some performance however.
Nitrous can be used for any length of time if setup properly. We have lots of users that use them for Top speed runs, even in the salt flats. It just takes the right parts and tuneup.
Sadly, 4th and 5th gear is where hes going to need nitrous the most, because he won't be able to keep up with the bike without it.
I think with proper rear gears and nitrous he may even win.
Sadly, 4th and 5th gear is where hes going to need nitrous the most, because he won't be able to keep up with the bike without it.
I think with proper rear gears and nitrous he may even win.
Do you even know what bike this is?
With 3.42's that thing should go 150+mph in 4th ... what kinda race is it? 1st one o 200mph?
We raced a 750 Sarad form a dig up to More than 1/4 Mile in my friend's Mustang LX ( 125 shot ) and here the result
http://www.youtube.com/watch?v=3Qum43ShMHc
It seems like we need to test the car with sprayed 2nd, 3rd, 4th and see if we can keep up to 800 meter ( 1/2 mile ) or not while we reached that limit of 4th N/A at 700 Meter ) otherwise we need to start without spray from 2nd and arm the system in 3rd and 4th

Thanks 03supercobra .. it seems the only way to go .. thanks for pointing me to that .. it will be much better than gear change
.. really appreciated
.. hope the backfire didn't damage anything or only the intake ?How big is the shot? Which tires you're using?
You can try going for a smaller shot to use it for longer, or install a water-meth kit to cool the engine
It's going to be a tough race anyway.
the race gonna start in 2nd, I have good tire and suspension mods .. also progressive controller is there to soften the hit if needed
I think with proper rear gears and nitrous he may even win.
Again thanks guys for sharing such great information and ideas ..
Last edited by Cold Zero; Dec 16, 2010 at 06:55 AM.
We raced a 750 Sarad form a dig up to More than 1/4 Mile in my friend's Mustang LX ( 125 shot ) and here the result
http://www.youtube.com/watch?v=3Qum43ShMHc
It seems like we need to test the car with sprayed 2nd, 3rd, 4th and see if we can keep up to 800 meter ( 1/2 mile ) or not while we reached that limit of 4th N/A at 700 Meter ) otherwise we need to start without spray from 2nd and arm the system in 3rd and 4th

Now another expert is saying no in 5th .. so I think the below idea sounds the way to go
Thanks 03supercobra .. it seems the only way to go .. thanks for pointing me to that .. it will be much better than gear change
.. really appreciatedThat's why Fuel Pressure Safety Switch is a cheap insurance
.. hope the backfire didn't damage anything or only the intake ?150 shot and I'm running 275/40 17 MT tires .. It seems the 28" tire is the way to go
the race gonna start in 2nd, I have good tire and suspension mods .. also progressive controller is there to soften the hit if needed
Actually I'm not looking to win .. a close race is enough, it will not be for cash
Again thanks guys for sharing such great information and ideas ..
I race for fun not for cash, and down here races for cash are rare ( 1 race for cash might be happened a year ) ... and it will only ended up making hates amoung race cars owners and I don't like that
And it's very simple.
NEVER, NEVER, NEVER give anyone the race that they want. If you do you are giving up a chance at the win. Even if it's just for fun.
I also had a 9" rear with 4.11's. The car had full bolt-ons and was cam only at the time.
My best advice is if you're worried about spraying your car then don't do it. A race isn't worth blowing something up if you can't afford it.


