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Some nitrous + turbo questions


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Ok here is my planned setup. Super 60 T3 with NX wet kit. What I want to do is use the nitrous to spool the turbo and have the nitrous cut off at a certain RPM. Ive heard of window switches that can do this. So I think Im going to use that. I was wondering what ignition to use. My car's engine is a 4cyl 2.0l 16v DOHC.

I was just wondering if the window switch would be ok to use and what ignition management to go with.

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You should never need nitrous to spool a turbo unless your trying to make stuipd power on a big turbo, too big for the engine really. Not a snowflakes chance in hell you should need it.

 

Turbo lag (spool up really, lag is techincially the time it takes the air to move through the system once the throtel is depressed) is overrated! From the sounds of past post your doing a pretty modest setup, if you get a smaller turbo, spool up time should be minimal. Full boost by somewhere in the 2.x krmp range, nothing to worry about at all!

 

When you shit, if your racing, you'll never see below whatever RPM your seeing full boost by.

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yes there are alot of fancy digital controllers, and they are neat, have pretty buttons and a price tag to go with them. There is another way though. It requires a pressure switch that will work at low pressures, say 4 to 20 PSI. You install that in the manifold so that when you hit a certain boost level,the nitrous disengages. Say 6 PSI, maybe 8. It will need adjusted to your liking. This can also be accomplished with a window switch, but it's not as acurate, reason is that if you are at high RPM, and coasting, then nail it, even though the turbo is spinning down and needs brought bad up to speed, you may be above the RPM level that the window switch will allow the system to operate. The other thing with running the system like this is you can install a WOT (Wide Open Throttle) switch to fire the system, then a toggle switch to arm the system. No button to hold down that way. The other option, if you want to get hairy with it, is throw a 50 shot to it at low rev's for more torque out of the hole, then switch it out with a pressure switch, then at 5000 RPM or so bring it back in to just above above your shift point with a window switch. You want the window switch because if you miss a shift, with that much nitrous flowing, the car can keep reving past the ignition limiter because of pressures involved in the cylinders lighting off the mixture without the plugs firing. Sort of like dieseling, but far worse on the motor. The other option is to buy a second set of solinoids and a fogger nozzle, jet it to 40 or 50 horse, and fire that circuit to increase torque. Drop it out with the pressure switch. Then have a second stage, being the regular system, set it to 100 shot or what ever, and have it come in with the window switch.

 

I say all this figuring that you know what your motor can take, and will spray with some restraint. A motor can take more spray at higher RPM, but I would advise restraint as you can break things, so I ain't responsible if you get nutz.

 

One other thing, NEVER SPRAY BEFORE A TURBO, always spray into the manifold, doing this wrong is bad, very bad. As mentioned before, backfires in a turbo are not good at all.

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Originally posted by Desperado:

yes there are alot of fancy digital controllers, and they are neat, have pretty buttons and a price tag to go with them. There is another way though. It requires a pressure switch that will work at low pressures, say 4 to 20 PSI. You install that in the manifold so that when you hit a certain boost level,the nitrous disengages. Say 6 PSI, maybe 8. It will need adjusted to your liking. This can also be accomplished with a window switch, but it's not as acurate, reason is that if you are at high RPM, and coasting, then nail it, even though the turbo is spinning down and needs brought bad up to speed, you may be above the RPM level that the window switch will allow the system to operate. The other thing with running the system like this is you can install a WOT (Wide Open Throttle) switch to fire the system, then a toggle switch to arm the system. No button to hold down that way. The other option, if you want to get hairy with it, is throw a 50 shot to it at low rev's for more torque out of the hole, then switch it out with a pressure switch, then at 5000 RPM or so bring it back in to just above above your shift point with a window switch. You want the window switch because if you miss a shift, with that much nitrous flowing, the car can keep reving past the ignition limiter because of pressures involved in the cylinders lighting off the mixture without the plugs firing. Sort of like dieseling, but far worse on the motor. The other option is to buy a second set of solinoids and a fogger nozzle, jet it to 40 or 50 horse, and fire that circuit to increase torque. Drop it out with the pressure switch. Then have a second stage, being the regular system, set it to 100 shot or what ever, and have it come in with the window switch.

 

I say all this figuring that you know what your motor can take, and will spray with some restraint. A motor can take more spray at higher RPM, but I would advise restraint as you can break things, so I ain't responsible if you get nutz.

 

One other thing, NEVER SPRAY BEFORE A TURBO, always spray into the manifold, doing this wrong is bad, very bad. As mentioned before, backfires in a turbo are not good at all.

That is not correct. While backfires on a turbo aren't good, it's perfectly fine to spray (smaller shot) before the turbo, if using a dry kit. Many import (actual drag only race cars), are doing it on a daily basis. I've seen 2 in person that are running anywhere from a 30-50 shot to get a T-78 to spool on a 1.6. It depends on what your going for. If you want the turbo to spool then go before the turbo (based on your setup that won't be needed), if you just need a a shot to get ahead of the guy then go however you want. Nothin like spraying to get ahead of the guy just to dump him at the finish line and break him out :D
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Originally posted by Desperado:

This can also be accomplished with a window switch, but it's not as acurate, reason is that if you are at high RPM, and coasting, then nail it, even though the turbo is spinning down and needs brought bad up to speed, you may be above the RPM level that the window switch will allow the system to operate. The other thing with running the system like this is you can install a WOT (Wide Open Throttle) switch to fire the system, then a toggle switch to arm the system. No button to hold down that way.

I say all this figuring that you know what your motor can take, and will spray with some restraint. A motor can take more spray at higher RPM, but I would advise restraint as you can break things, so I ain't responsible if you get nutz.

Ok maybe i needed to clarify a bit but what you said is helpful. I already have an arming switch and a WOT switch. I was going to use those along with the RPM window switch. So my throttle will have to be wide open, under whatever rpm i set it to shut off at and the arming switch has to be on, so basically if i was cruising i wouldnt be spraying for no reason. I also found this, and thought this might be helpful on when I should shut the window switch to shut the nitrous off

 

http://www.speed-factor.com/misc/betaplot.jpg

 

Thats the compresser map for the the turbo on my specific engine. So with that said what would be a good RPM to shut it off at..

 

Also here is where my nitrous is installed so it shouldnt backfire to the turbo

http://www.digitalpose.com/mbr/1/27558/p/499919_2084938373148324261_vl.jpg

 

That piece sits between my MAF and my TB

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Well the arm switch keeps you from going to the nitrous all the time as does the WOT switch in the line, as far as spraying before the turbo, if it backfires, it can take the housing apart, and very easily break fins. But if we are talking drag only applications, spray into the exhaust, that will bring a turbo up really fast, but can not be done for any length of time because the heat levels will go critical very quickly. And I guess that spraying with a pressure switch, through a WOT switch, while it will not spray unless you are at WOT, is only an option.
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With a turbo car, especially a 4 cyl, i would choose a wet kit 9 out of 10 times. The nitrous backfire risk is always going to be there, but how common is it really. Its not that challenging to take precautions against it.

 

In a turbo system you are already dealing with elevated cylinder pressures, by taking away the even distribution assurance of a direct port kit, you are risking running an uneven load in each cylinder. Each cylinder is however still each getting x amt of fuel. x amt of fuel might not be enough if 20% more nitrous goes into the first available cylinder.

 

Additionally, by relying on your injectors to react so quickly to both the onset of boost AND the introduction of nitrous you face the risk of over running them without being able to compensate in time to avoid replacing your block.

 

It comes down to nitrous backfire = replace intake mani.

 

Injector overload/uneven distribution = replace block

 

I choose the first.

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Originally posted by iwishiwascool:

With a turbo car, especially a 4 cyl, i would choose a wet kit 9 out of 10 times. The nitrous backfire risk is always going to be there, but how common is it really. Its not that challenging to take precautions against it.

 

In a turbo system you are already dealing with elevated cylinder pressures, by taking away the even distribution assurance of a direct port kit, you are risking running an uneven load in each cylinder. Each cylinder is however still each getting x amt of fuel. x amt of fuel might not be enough if 20% more nitrous goes into the first available cylinder.

 

Additionally, by relying on your injectors to react so quickly to both the onset of boost AND the introduction of nitrous you face the risk of over running them without being able to compensate in time to avoid replacing your block.

 

It comes down to nitrous backfire = replace intake mani.

 

Injector overload/uneven distribution = replace block

 

I choose the first.

Backfires can be fairly common (you cant do a thing to protect against sticking solenoids, or what if he bogs launching?). You'd be replacing more than just the intake if it was a bad backfire, especially on a non-intercooled application (It could easily destroy the turbo). Uneven distribution can be just as great with a single fogger as with a single dry nozzle, thats not even an issue.

 

I am NOT a fan of filling long runner intakes with air/fuel, they are not designed to handle fuel. A direct port system would be a entirely different thing, but I assume he would use a single fogger nozzle.

 

You can tune for a dry shot, its not that hard, and the risk of a backfire goes WAY down.

 

But IMHO using nitrous to spool a turbo on an application such as this is a bad idea in the first place. Design the system correctly and it should spool just fine.

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are you using this tibby as a drag car?

why are you using such a big turbo?

i doubt youll be spraying every time you take off on the street.

 

i hope your building up your engine as well, since tibrons dont come turbocharged from the factory.

making a NA engine into a FI engine is a pain.

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Guest mudbutt
Originally posted by *:

are you using this tibby as a drag car?

why are you using such a big turbo?

i doubt youll be spraying every time you take off on the street.

 

i hope your building up your engine as well, since tibrons dont come turbocharged from the factory.

making a NA engine into a FI engine is a pain.

I think you are thinking 60-1.... He plans on using a super 60. That is a pretty small turbo ~250 hp
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i posted the compressor map on how that turbo acts with the engine in my car. But as far as a tiburon engine being an NA vs FI it actually responds better stock to FI vs NA. The stock pistons handle up to 250hp and the stock rods handle up to 300hp but the clutch is crap but not really part of the engine but the stock crank shaft has been up to 700hp in Korea. They dont bother with aftermarket cranks. Really to get 250hp out of a Tib you jsut need a new clutch and a bigger fuel pump.
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