You can call
Eric at Bottlefed Racing (909) 793-3681 after 2pm
He has been doing nitrous kits since 1992. and he will tell you the same thing

 

I rather rebuild a solenoid than a motor

 

First off, I probably have more experience with nitrous than you ever will. I've had 4 camaros with automatic transmissions, all on nitrous and without a window switch. None of them with any problems. My buddy Ken has a 2002 Z28 with a 150-shot of nitrous on an auto and no window switch. My best friend Phil has a '94 383 stroker with a 200-shot of nitrous on an automatic with no window switch and no problems. I also work at a nitrous shop and I just love guys like you who come in and buy anything we say might make your car safer. A window switch is a waste of money (for automatic transmissions) that dealers tell you to buy so they can make more money off of you. Automatic transmissions are automatic, the computer controls the shifts so there is no human error possible. Now, on a manual, human error becomes a factor, and this is when a window switch becomes a good idea. I know the automatic transmission could slip and bounce off the rev-runner and hurt the motor, but if you are racing on a transmission that is already slipping, you're a dumbass. Nitrous should not be taken lightly. If you have a motor and trans with 85k miles on it, and has any little problems, nitrous will make that little problem a very big one, regardless of the window switch.

If you have a manual transmission, I would highly recommend a window switch.

 

Calm down...you're entitled to your OPINION, but there's no need to take offense when others disagree. Just because YOU haven't had a problem with your auto and no window switch, doesn't mean lots of others haven't. You're in the company of LOTS of people with far more experience than you have or ever will have. There is no right or wrong answer, just don't state your OPINION as fact.

 

Go ahead and show your ignorance on why a window switch is even really needed for auto trannies, it is not an issue of operator error in shifting vs. computer controlled. It is an issue of keeping a tranny alive. Ask every tranny builder on here that is a sponsor about window switches. They INSIST that you run one on spray. Why? Because the clutches can hold a lot of power under acceleration, but putting a ton of power (torque) through the trannies during shifts will kill it quick.

...and all it takes is that first time the tranny slips to wipe out the motor and possibly tranny.

Some of us are smart enough to invest in a $100 switch instead of rebuilding a $1500 tranny and converter combo.

...and FYI I've had 3 friends kill stock trannies due to not using window switches.

BTW, what aftermarket ignition box are you using?

 

Heys guys, I haven't posted in a while but thought I could contribute to this thread. At first, I immediately jumped to my own conclusions on the benefits and negatives to running a window switch on a N2O A4. I have had two cars that have had an auto Lt1 that I spayed on through the shifts without a window switch.

I first thought the only downside was the cost of the switch. There are other concerns that I have. First, I think spraying throught the shifts obviously poses more stress and a higher chance of failure than letting off at the top of gears of more efficiently using a window switch to automatically disable the nitrous between auto automatic shifts. So yes, I agree with the transmission manufactures that using a switch makes it much safer for your tranny to live.

While I assume all of know that the switch on the low end will prevent nitrous being applied too early, it equally protects the motor in the event of over revving as long as the switch engages AFTER the rev limiter kicks in. So I first thought in this respect that a window switch is a pretty good idea. It was after considering all these variables that I thought of one potentially damaging problem if someone is using this switch.

Transmission safety aside, when nitrous is engaged, it is best to leave it on throughout your acceleration rather than turning on and off. This may be done when someone is toying with a competitor or does not want to give away thier own cars' full race potential. If a window switch is activating and deactivating the nitrous throughought the run, you subject the motor to many stresses of the on and off power. This is why I would not want the the switch on the car. The only way I would run it is if the switch actrivated after the rev limiter thus activating only when a trnsmnission failuyre occurred. Yes, this would not protect your trans but would protect the moter and provide beter quarter mile times and speeds.

Conclusion, The motor is more important than the trans.

 

Alot of really good points i love threads like this.

To Each there own you know?

personally the way i would run it would
Stock revlimiter moved out of reach for the first part.
I Still think a window switch is a good idea. to make sure the nitrous isnt engauged at too low of a rpm, you can argue this point till someones bleeding from the ears but it wont get us anywhere.

So lets say your running a msd box and your revlimiter on the box.

You could set your window for the lowest rpm you would want to spray and put the next pill out of reach also, like past the msd rev limiter now added on.
this to me would be the safest way to handle spraying threw shifts.

Someone couldnt pay me enough money to go threw the chance of even a blurp on the stock rev limiter on nitrous.

 

You can get a window switch for 85 bucks, its really not a big deal.