Nitrous / Turbo combinations

[Alky V6]

I agree with you completely. If your combo is spooling up just fine and you're happy with running around town with that stall speed, I see absolutely no reason to bother with nitrous.

The plan to use nitrous with a combination should be a forethought so that the rest of the combo can be set around the planned use of nitrous. If your combo was planned without nitrous in the picture, then most likely if all the components were picked correctly, you shouldn't need nitrous.

Some of the things to consider when putting a combo together with the forethought of using nitrous would be:

Torque converter stall. You can go with a tighter, more efficient T/C without worrying about turbo spool up time.

Cubic inch displacement. You can go with a smaller cube engine in relation to the turbo size without worrying about spool up time. Making the expense of stroking unnecessary.

Static compression ratio. You can go with a lower static compression ratio for a safer build without worrying about spool up time.

Turbo sizing. You can go with a relatively large turbo for your engine size to get better top end efficiency without worrying about spool up time.

Launch stradegies. For drap racing you can taylor the shot size and tuning to get the best 60 ft. possible without having to go through the drama associated with turbo drap cars. You can stage and leave as if you were driving a naturally aspirated car.

Instantaneous performance. If your searching for absolutely zero turbo lag. Nothing beats a nitrous/turbo combination. Nothing.

So much planning goes into a turbo engine with turbo spool time being such a big factor when picking specs for the engine.
When you are picking the specs for a turbo engine with the forethought that nitrous will be used, it's like being set free. There is so much more ground to explore with a nitrous/turbo engine.

 

[TARZAN]

Bump for good info. I've got a 3,000 stall, and had a TE-44....it spooled so quick, the nitrous was almost pointless. I've now got a GT6131, stock longblock....spool isn't necesarrily *slow*, but its noticeably slower than before. Now, I can use the nitrous to give instant spool, which is perfect for situations where the traction isn't an issue. On other occassions, such as some of our local tracks, traction isn't always as readily available as one would hope for....so this gives you a chance to hook, make sure it sticks, then kit it and still no more worries with lag.

I did find out, when I went from a 30 shot to a 50 shot, boosting 25 lbs., that with my same tune +1.5 psi fuel pressure, it seemed to run good, but I had problems blowing spark out up top. I've had better luck gapping mine to .030-.032 if I intend on holding it out for a full 1/4, as opposed to just using it off the line...

Just my experience.

-Will

 

[Alky V6]

An observation I'll pass on. Some people setup their combination of converter stall speed and turbo in such a way that when you really don't want any boost, you're stuck with it. Take for instance a climb up a grade. You start pushing into the throttle to maintain a reasonable uphill climb and the boost gauge starts climbing. All I can think is, 'man, there goes my intake air temp'. Thermal load on the engine increased much more than you really were wanting. With nitrous in the picture, you can run a larger turbine housing, pushing out the boost point, making the top end more efficient and running the engine cooler in some of the normal driving situations where unwanted boost was a problem. Not to mention, being able to go with a tighter stall that can only help gas mileage.