Nitrous at low RPM - Nitrous Oxide Forum

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Nitrous at low RPM
Saturday, September 27, 2008 8:14 AM
okay I am moving this ? from the boost thread as a turbo setup for my offroad rig is not feesable.

I want to steady spray at low RPMs from 1500 up to 4,500 when I get bogged down in the mud or up a steep hill. is a standard Nitrous kit availabe for this?

I read the sticky to search for my only concern:
Q. How high must the RPM's before activating nitrous?
A. The RPM level is not as important as is the motors ability to rev freely when the nitrous is engaged, I.E. If the vehicle is in low gear, nitrous can be engaged at any time, but if the vehicle is in a higher gear moving at a slow speed when the nitrous is engaged the engine will detonate and damage will occur.

here is what I am working with:
stats:
95.5 Isuzu Rodeo
3.2 SOHC V6
9.3:1 compression
47K miles
5 speed
4:10 gears
Dana 44 rear
LSD

I run 32x11.50 SuperSwamper TSL's and they are hard to get turning when bogged down with mud... unmounted tires weight at 55lbs each, plus another 30-40lbs for the rims. so I need all I can get to get them moving. I have a really low crawl gear that can move them, but 4L redlines at 15mphs.




Re: Nitrous at low RPM
Saturday, October 11, 2008 9:18 PM
Spray the nitrous until your tires are at the right speed for you and then kill it. Since they aren't "planted" on pavement, there should be no drivetrain concerns.

As for the motor, I used to spray all the time from dead stops. You're still dumping the fuel, therefore you're technically in the clear. Is it something I would do ALL the time to my motor? Definitely not--but drivetrain breakage tended to be my bigger concern back then.

Just make sure you're not spraying between gears Use a wide-open-throttle switch on your TB






Re: Nitrous at low RPM
Sunday, October 12, 2008 6:16 AM
Ztwenty4door wrote:okay I am moving this ? from the boost thread as a turbo setup for my offroad rig is not feesable.

I want to steady spray at low RPMs from 1500 up to 4,500 when I get bogged down in the mud or up a steep hill. is a standard Nitrous kit availabe for this?

I read the sticky to search for my only concern:
Q. How high must the RPM's before activating nitrous?
A. The RPM level is not as important as is the motors ability to rev freely when the nitrous is engaged, I.E. If the vehicle is in low gear, nitrous can be engaged at any time, but if the vehicle is in a higher gear moving at a slow speed when the nitrous is engaged the engine will detonate and damage will occur.

here is what I am working with:
stats:
95.5 Isuzu Rodeo
3.2 SOHC V6
9.3:1 compression
47K miles
5 speed
4:10 gears
Dana 44 rear
LSD

I run 32x11.50 SuperSwamper TSL's and they are hard to get turning when bogged down with mud... unmounted tires weight at 55lbs each, plus another 30-40lbs for the rims. so I need all I can get to get them moving. I have a really low crawl gear that can move them, but 4L redlines at 15mphs.


I think you are trying to fix a broken leg with a bandaid.

I have been in the off road community for 20 years now, cavaliers and street cars are actually new to me. It sounds like your problem lies in your setup, and nitrous will only act as an expencive bandaid fix.

first thing that jumps out at me is the engine and gearing. It sounds like you just have too much tire, and not enough engine and gearing to turn them where needed. Low gear is intended for going over obstacles, up hills and thru mud. that is the whole point, low speed high torque. If you are talking about mud-drags, where you need speed and power, i suggest you look into a V-8 swap.

for the kind of usage you are talking about, you would go thru nitrous so fast that you would need your entire back seat just for spare tank storage. Keep in mind that a 100 shot of N2O uses just under a pound per 10 seconds. most N2O tanks are 10-15 pounds. so if you had a 15 pound tank and a 100shot, you would burn thru the tank in 3 minutes. I know i have spent 3 minutes trying to get thru one mud pit. So unless you plan to carry like 10 spare tanks or have NOS setup a refilling station half way thru your favorite trail, i think you would find the duration of the nitrous to be you biggest issue. that and the fact a 15 pound bottle can cost $75 to refill... you might find a V-8 swap to have paid for itself after about 3 trail runs with nitrous.

oh and there is always the chance that your tires could catch traction, or get hung up on something while spraying, which could quickly drop your RPMS and bog down the engine... the N2O system wouldnt know or care, and could quickly grenade your engine.

For your normal off roading, positive displacement superchargers, or just raw N/A power, and gearing are your best friends... anything else can stab you in the back when you least expect it.



Re: Nitrous at low RPM
Sunday, October 12, 2008 12:34 PM
Thanks guys for your input....I didnt think about what would happen when I catch traction, that would be bad. I aslo didnt think about the amount of N2O that would be used it would take up quite a bit of space for 2 bottles at least..., im not doing mud drags ( although I always wanted to go to them) but just a few mud holes a few us of go too froading at. I guess i will rethink my plan, I may go with a remote turbo set up if I can find a small turbo to give me about 4-5lbs of boost at low RPMs....just need to find one that will work with my displacement.



Edited 1 time(s). Last edited Sunday, October 12, 2008 12:37 PM


Re: Nitrous at low RPM
Sunday, October 12, 2008 12:51 PM
Ztwenty4door wrote:Thanks guys for your input....I didnt think about what would happen when I catch traction, that would be bad. I aslo didnt think about the amount of N2O that would be used it would take up quite a bit of space for 2 bottles at least..., im not doing mud drags ( although I always wanted to go to them) but just a few mud holes a few us of go too froading at. I guess i will rethink my plan, I may go with a remote turbo set up if I can find a small turbo to give me about 4-5lbs of boost at low RPMs....just need to find one that will work with my displacement.


well whole problem with turbo is they arent designed for low RPM. you need to get the revs up to get the turbo spooled up. so you would need a pretty small turbo to spool up fast enough to give you any help way down low where you need crawling power.

it sounds like you either need a positive displacement supercharger, or a bigger engine.

you might just want to try and make better use of your 4LO. that would be FAR cheaper than any of your other options. you really dont need to be going over 15mph when climbing steep hills or bogging thru mud. I have seen many guys with little 4 cylinders handle big obstacles just fine with the use of 4lo.

as i mentioned the only time you really need speed and power is in comeption mud drags. and then you need like 1000+ HP



Re: Nitrous at low RPM
Sunday, October 12, 2008 1:05 PM
yeah I was just checking out the main Isuzu site, most say that my 32x11.50s are to wide a tire for our motors, I will see if I can trade down to a 10.50 or so. I think my money will be better spent with a rear locker (have LSD now) maybe some terra-low gears. Thanks for your input!



Re: Nitrous at low RPM
Sunday, October 12, 2008 1:43 PM
Ztwenty4door wrote:yeah I was just checking out the main Isuzu site, most say that my 32x11.50s are to wide a tire for our motors, I will see if I can trade down to a 10.50 or so. I think my money will be better spent with a rear locker (have LSD now) maybe some terra-low gears. Thanks for your input!


Actually tire width has little to do with your engine at all. it is the height of a tire that gives leverage to the obstacles. taller tires require more power to turn.

tire width only effects traction. a 15" wide tire has 50% more grip on the ground than a 10" wide tires contact patch. typically the only thing that effects is the stress on drivetrain, as more tractions typicaly means a part will give before you will loose traction.

although i guess if you are plowing thru mud, a wider tire will be that much more rubber that needs to push thru the muck. less aerodynamic.. more mud ressitance...



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