Nitrous. M50TU

[AllenE36]

I have a quick question for those who have used nitrous before with M5x motors.

I bought a Nitrous Express wet system for my prelude and had been running it for 3 years. 75 wet shot, had it dyno tuned and everything.
Put out 247whp and I think 227 torque. http://www.youtube.com/watch?v=Opl5UdiJj84
Anyways I sold my prelude and now have an E36 with a M50TU. I kept my nitrous system and its been sitting in my garage for a while.

I am interested to know what will be safe for this motor. I knew my H22 Honda motor inside and out and kept that thing running perfectly, but I am just beginning to learn about the BMW M50's.
From my hypothesis I believe between 100-120 shot would be safe/reasonable shot for this motor. I figured out I will use jets 53N & 31F to get a 100 shot for testing.

I am just looking for someone on this board who can confirm my "safe" ~120shot estimate. Thanks.

[ritoab]

The best approach would be to start out small and work your way up to 120shot. For example successfully run 50 shot, 75 shot, 100 shot then 120 shot. Take baby steps.
Do a Leak down/CR test to make sure all is well. Inject right before the TB with a wet system. Whatever you do do not inject this shot before MAF. It's common to retard timing about 1-3 degrees of every 50 shot of nitrous. The dme will probably do that for you but most feel better not putting that control in the DME hands. Good luck and remember to start out slow working your way up to a 120 shot.

[AllenE36]

Gotcha, thanks for your help. I'll start out with a 50shot Once I get everything hooked up and tested.
Just have to go get some colder ngk plugs and change my oil first.

[ritoab]

Gotcha, thanks for your help. I'll start out with a 50shot Once I get everything hooked up and tested.
Just have to go get some colder ngk plugs and change my oil first.
No problem
Get two sets of BkR7E spark plugs they are very cheap. You will have to regap them.

[abrad2912]

made me miss my prelude....

[AllenE36]

I got another quick question.
I was really interested in getting the Conforti/Turner Chip for my pre 95 E36.
This chip just modifies the fuel maps and cutoff limit correct?
Would it be an issue running nitrous + the chip? Should I just skip chipping all together?

[TRM]

The ECU won't retard the timing for you.
An off the shelf performance chip will generally alter the WOT fuel maps and the timing maps, as well as any needed/wanted changes to idle and rev limits. Adding timing and adding nitrous may not be the best thing to do.

We can do a multi-tune, one performance tune, and a tune for nitrous. (And/or could do both on the dyno). If your nitrous system has an output that can trigger a relay for switched ground, the map selection in the ECU could be an automatic thing.

[m3saloon]

Another reason i f-in <3 TRM

[Impulsed7]

The ECU won't retard the timing for you.
An off the shelf performance chip will generally alter the WOT fuel maps and the timing maps, as well as any needed/wanted changes to idle and rev limits. Adding timing and adding nitrous may not be the best thing to do.

We can do a multi-tune, one performance tune, and a tune for nitrous. (And/or could do both on the dyno). If your nitrous system has an output that can trigger a relay for switched ground, the map selection in the ECU could be an automatic thing.

Could you guys do the same thing for an S50B32, having the car in house? If i could drive the car down there for a few days? I know its a whole different beast.

[ritoab]

The ECU won't retard the timing for you.
An off the shelf performance chip will generally alter the WOT fuel maps and the timing maps, as well as any needed/wanted changes to idle and rev limits. Adding timing and adding nitrous may not be the best thing to do.

We can do a multi-tune, one performance tune, and a tune for nitrous. (And/or could do both on the dyno). If your nitrous system has an output that can trigger a relay for switched ground, the map selection in the ECU could be an automatic thing.

Thanks for stepping in Mike, This is the best option by far for his setup.
As he stated with a advance chip more than likely timing is being added.
It wouldn't hurt so much on say a 25-50 shot of nitrous but once you start going above that for every 50 shot of nitrous you need to remove 1-3 degrees of timing for safety. Since that dme doesn't retard or advance timing I would go this route. you were going to spend the monies for the Shark chip or whatever it's call might as well get a real tune.

[BMWMPow3r]

The m50 manifold isn't the best design for nitrous since some runners will generally get more nitrous than others. Throwing off the mixture in all the cylinders. causing a generally uncontrollable lean mixture in some of the banks which will burn out some cylinders over time. Over a 75 shot might not be safe, but I would keep an eye on the condition of each spark plug while upping the shots. But if you tap into the individual runners and run 6 nozzles that way, I've heard you can go over 150 shot. with no problems, given you have all of the safety mechanisms, not just a simple nos kit.
meaning wideband A/F gauge, progressive controller- with low fuel press, low/high rpm cutoff, etc.

[PEI330Ci]

The m50 manifold isn't the best design for nitrous since some runners will generally get more nitrous than others. Throwing off the mixture in all the cylinders. causing a generally uncontrollable lean mixture in some of the banks which will burn out some cylinders over time. Over a 75 shot might not be safe, but I would keep an eye on the condition of each spark plug while upping the shots. But if you tap into the individual runners and run 6 nozzles that way, I've heard you can go over 150 shot. with no problems, given you have all of the safety mechanisms, not just a simple nos kit.
meaning wideband A/F gauge, progressive controller- with low fuel press, low/high rpm cutoff, etc.

You can run a lot more than a 150 shot with a properly setup DP system:

http://i36.photobucket.com/albums/e29/PEI330Ci/WON%20Pro%20Series%20S50/July2010-57.jpg

http://i36.photobucket.com/albums/e29/PEI330Ci/WON%20Pro%20Series%20S50/April2011-60.jpg

I flowed this system to 470hp, but dialed it back to 3 safe power levels for the owner: 75 / 150 / 300hp. (He's starting at 75)

Perfect distribution as well, spent a lot of time on the flow bench making sure of that.

[BMWMPow3r]

:eyecrazy

[Rob43]

You can run a lot more than a 150 shot with a properly setup DP system:

http://i36.photobucket.com/albums/e29/PEI330Ci/WON%20Pro%20Series%20S50/July2010-57.jpg

http://i36.photobucket.com/albums/e29/PEI330Ci/WON%20Pro%20Series%20S50/April2011-60.jpg

I flowed this system to 470hp, but dialed it back to 3 safe power levels for the owner: 75 / 150 / 300hp. (He's starting at 75)

Perfect distribution as well, spent a lot of time on the flow bench making sure of that.

Adam, I really like it when I get to see pictures. (please, No funny comments)