Anyone ever run nitrous on a 4.0??
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Seasoned Member
Joined: Jan 2011
Posts: 387
Likes: 1
From: CT
Year: 96
Model: Cherokee
Engine: 4.0
lol, most of your stock motors in your trucks were slower than dog turds back then. But we'll leave that dead horse lay. How many miles did you say you have on that motor? You happen to regear when you went to those 35's? That's the biggest problem I see as far as your motor, trans, transfer case and driveshafts.
@Hooper - Yes. 4x4 engines... this is going in a 4x4, not an indycar. two completely different animals. FYI, dual overhead cams and coil packs can kick rocks, along with their aluminum blocks. Don't get me wrong, I got all that on my bike, but that wouldn't hold up very well climbing over rocks and logs or bashing through mud. Just an opinion.
@Hooper - Yes. 4x4 engines... this is going in a 4x4, not an indycar. two completely different animals. FYI, dual overhead cams and coil packs can kick rocks, along with their aluminum blocks. Don't get me wrong, I got all that on my bike, but that wouldn't hold up very well climbing over rocks and logs or bashing through mud. Just an opinion.
blah blah blah LOL
The 4.0L is a great start with the 8.8-1 compression ratio, which is great for adding boost/n20, I would keep it at a 50-100 shot wet. you will want a wet shot to compensate for the added air/compression. the factory fuel system will not handle the added shot fast enough and will cause it to lean out while spraying.
You will also need to get a wide band setup to moniter the rich/lean condition to watch for any signs of fituige/failure before it costs you a motor. Your also going to want to get colder spark plugs 2-3 heat ranges depending on the size of the shot, to help with predetonation.
A lot of people will recomend letting off the spray between shifts to limit the flare up between gears. I would also recomend window switches, one that will only spray at rull throttle, and one that will cut spray 500-1000 before redline. (don't want to spray into reline
)
Do it right and have a lot of reliable fun at the push of a button, cheap out and the fun time is limited with a costly aftermath. do a lot of reading on n20 and what people have had work and fail on the 4.0L.
Good luck, N20 is amazing!
The 4.0L is a great start with the 8.8-1 compression ratio, which is great for adding boost/n20, I would keep it at a 50-100 shot wet. you will want a wet shot to compensate for the added air/compression. the factory fuel system will not handle the added shot fast enough and will cause it to lean out while spraying.
You will also need to get a wide band setup to moniter the rich/lean condition to watch for any signs of fituige/failure before it costs you a motor. Your also going to want to get colder spark plugs 2-3 heat ranges depending on the size of the shot, to help with predetonation.
A lot of people will recomend letting off the spray between shifts to limit the flare up between gears. I would also recomend window switches, one that will only spray at rull throttle, and one that will cut spray 500-1000 before redline. (don't want to spray into reline
) Do it right and have a lot of reliable fun at the push of a button, cheap out and the fun time is limited with a costly aftermath. do a lot of reading on n20 and what people have had work and fail on the 4.0L.
Good luck, N20 is amazing!
CF Veteran
Joined: Sep 2010
Posts: 4,968
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From: Salt Lake City, UT
Year: 2000
Model: Cherokee
Engine: 4.0L
your suposed to lift ONLY for auto's... when the clutches engauge it will flair and cause them to slip and burn the clutches. over time it will ruin the trans.
Yes N20 and boost love compression. your rods on the other hand DO NOT... If you had forged rods/pistons head studs 11-1, or 10-1 would be ideal... but you don't
Yes N20 and boost love compression. your rods on the other hand DO NOT... If you had forged rods/pistons head studs 11-1, or 10-1 would be ideal... but you don't
CF Veteran
Joined: Jun 2010
Posts: 1,378
Likes: 0
From: Hayward, CA
Year: 1996
Model: Cherokee
ive seen a 200 shot on a 3.5L V6 with 10.3:1 compression, all stock engine handle no problem. And the same design V6 takes 75-125 shots from a lot of guys no problem. You dont really run into trouble with compression unless youre just making too much HP for the rods (depends on the rods obviously what that limit is) or trying to spray without a good tune. In either of those cases the low compression will be more forgiving but youre still living on the edge
CF Veteran
Joined: May 2009
Posts: 9,047
Likes: 1
From: Indiana
Model: Grand Cherokee
I noticed hes from California... That explains it Donnie.
Last edited by dlundblad; Sep 27, 2011 at 04:37 PM.
Thread Starter
Seasoned Member
Joined: Jan 2011
Posts: 387
Likes: 1
From: CT
Year: 96
Model: Cherokee
Engine: 4.0
your suposed to lift ONLY for auto's... when the clutches engauge it will flair and cause them to slip and burn the clutches. over time it will ruin the trans.
Yes N20 and boost love compression. your rods on the other hand DO NOT... If you had forged rods/pistons head studs 11-1, or 10-1 would be ideal... but you don't
Yes N20 and boost love compression. your rods on the other hand DO NOT... If you had forged rods/pistons head studs 11-1, or 10-1 would be ideal... but you don't
Nitrous is a lot more compression friendly than boost. Much over 9:1 with boost without running race gas and you're begging for serious detonation and head gasket problems. A mild amount of nitrous can be run pretty safely up to 10.5:1 or so on pump gas as long as it's tuned safe. The biggest problem you will run into is cast pistons and stock head gaskets aren't detonation friendly. That's where a good tune comes in. None of that really matters though since the stock 4.0 is low compression. If it blows a head gasket maybe I'll do head studs, a decent gasket and deck the head to up the compression a little. I'm getting kind of excited to play with nitrous on this thing now...
CF ADMIN
Joined: Sep 2010
Posts: 34,088
Likes: 257
From: Lantana, Fl
Year: 1996
Model: Cherokee (XJ)
Engine: 4.Slow
Hey, don't crack on the Max Wedge or "true" Hemis cause those were the **** for their day. My 413 Max Wedge in my 71 Dart ate plenty of Mustangs, Camaros and just a Rev of the motor at a light made Ricers **** their pants. Hail to the king baby! Lol
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Joined: Mar 2009
Posts: 4,057
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From: Western NY
Year: 2001
Model: Cherokee
Engine: 4.0 I6
Just a note: I collected stock class mud bog trophies in the two times I ran without nos.. Really simple to place in top 3. Jeep + knowing how to mud bog + learning/understanding the mud bog density = top 3 finish
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