Question For Dsmjim!!!!!

[squeak10686]

Hey dsmJim got a question for you... I have been thinking and i have almost everything that was my initial goal...

16g with all supporting fuel mods... ETC ETC!!!! ( all the mods people are easily getting into the 12's with)

Im in a tsi awd and heres my question for you....

I have been thinking about puting in a 55 shot and would just like to know some of the problems i will have when running it and also what i will gain... i know the Power gain, but what about time gains... IM NOT BENCH RACING IN ANY SORT!!! im just looking for what the average amount a 55 shot will do on a awd turbo car... im sure many other people are interested too

Thanks alot and good luck tuning...
Andrew

 

[TimG]

Try a PM.

 

[Stapl3]

Try a PM.

You took the words right out of my mouth.

 

[DSMJim]

However since It's a lagitimate question I'll answer it here.

It all depends on how fast your car is running now. If your making 350whp and 300ft/lbs with your 16G meaning you have it setup pretty damn well and you have all the supporting mods you should be well into a mid 12 lets say 12.5 @ 110mph for arguements sake.

Now by adding a 50hp shot of nitrous lets assume an NX kit with jetting for a 50hp shot (whcih is a wet kit of course) and you spray right after the 1-2 shift. You will gain aprox 100whp and 115ft/lbs of torque. That just put your car into the 450whp and 415ft/lbs of torque range. In my best guess I would say this will take 6-7/10ths off your car. So you should be able to see a 11.8-11.9 @ 116-118mph with that added HP.

This is all however bench racing but typically the turbo cars I put spray onto (dsm's in particular) seem to gain in this range with an average driver on a average car. You could end up with less or more gain depending on your setup.

One thing to keep very clear in your mind is that you will want to run race gas when doing this type of thing and make sure your not under 1/4 tank of gas. When you launch all the gas go rushing to the back ofthe tank. If your runnign a very minimal amount of gas in the car your just asking to starve the pump and smoke the motor. I have acctually seen this happen when a guy was down around 1/8th of a tank of gas spraying on a stock 1G with 22psi of boost. He was running 12.0 @ 117mph and the next run he melted two valves in his head which is not pretty.

Nitrous is not for amatures so make sure your very familiar with what your doing and start very small with it to get used to it's effects and running it on your car. Do not go out and try and get your fastest pass the first time out. Your first shot should be 35hp shot (smallest NX jets) on 15psi just to see if you have everything setup properly and watch your boost to see what happens. Then turn it up from there. Starting with 25psi of boost and spraying 100hp shot on your first time out your just asking for trouble.

 

[squeak10686]

Wow... alot of that stuff you said was great to hear.... Yes I'll be using race gas and i will deffinately start out with a small shot...

but what do you think the limit would be on my stock internals... do you think it could hold 23psi and the 50 shot overall...

Another thing to talk about is do you think i will creep alot with adding the nitrous ( around how many psi creep will i need)

Also... What are some of the bad effects that are being experienced using the nitrous... Is it really "that much harder on my engine" any input you can give me would be great...

And yes its a turbocharged engine i will deffinately be using a wetshot...

 

[DSMJim]

Wow... alot of that stuff you said was great to hear.... Yes I'll be using race gas and i will deffinately start out with a small shot...

but what do you think the limit would be on my stock internals... do you think it could hold 23psi and the 50 shot overall...

Another thing to talk about is do you think i will creep alot with adding the nitrous ( around how many psi creep will i need)

Also... What are some of the bad effects that are being experienced using the nitrous... Is it really "that much harder on my engine" any input you can give me would be great...

And yes its a turbocharged engine i will deffinately be using a wetshot...

With really good tuning and being careful 23psi and a 50shot could last with a metal headgasket and ARP studs. Without your kinda asking for it. 1G big rods and pistons or 2G pistons will take the abuse however.

You may find creep anywhere from 2-5psi. Nitrous is a lot harder on engine parts, espically a turbo nitrous combination. Nitrous creates a lot of cylinder pressure very quickly where turbocharging does not. Adding nitrous to a turbo car provides almost instant spool up further complicating the problem. If you hit fuel cut with nitrous on that will definately cause problems. There are a few different things you need to be careful of, detonation is much more important now as a nitrous/fuel mixture will burn much more voilently than a non nitrous mixture. You just need to take more precautions thats all.

 

[squeak10686]

I'm sorry to keep on bugging you but since you really know your stuff here is what i would like to know

Will I need somethign mroe than the safc... I will have an LM1 quite soon and that should help me out quite a bit on staying on the safe side.

Also how hard is this going to be on my tranny since there will be that instant jerk... it seems that there could be quite a few problems with running it.. but the upside is amazing

thanks for your help jim
andrew

 

[DSMJim]

I'm sorry to keep on bugging you but since you really know your stuff here is what i would like to know

Will I need somethign mroe than the safc... I will have an LM1 quite soon and that should help me out quite a bit on staying on the safe side.

Also how hard is this going to be on my tranny since there will be that instant jerk... it seems that there could be quite a few problems with running it.. but the upside is amazing

thanks for your help jim
andrew

I am going to make it all work with the SAFC. Generally nitrous is pretty well setup so that it's in the correct air fuel ratio. I will however be watching it on my LM1 and making adjustments to my safc where needed if it's lean or rich in spots.

The trans could be a problem which is why I would turn it on in first gear and lift shift. Power shifting is really hard on the trans anyway but doing it with nitrous would be devistating. I plan on bilit shift forks, a new 3rd and 4th, new syncos around and a 4 spyder diff on my trans just to make sure.

One other things I will be messing around with is the retard function on my MSD DIS2. The thing about larger injectors with an SAFC is that your reducing the air flow to the computer which is how it compensates for the injectors. In doing this the computer will acctually advance the timing because its seeing less air flow. So we end up with pretty agressive timing in our cars with larger injectors. Advanced timing and nitrous are not a great mix. I plan to get my timing down to around 20deg at WOT (vs my 24-25 deg now) when spraying. THe MSD has the capability to retard 1 deg or 2 deg per 1000rpm starting at whatever RPM you want which is pretty cool so I'm going to be messing around with that a bit to get my timing where I want it.