question says it all. How much N20 can i safely run with a 406 with JE forged pistons, JE rings miniram and AFR heads?

 

unless you use high octane gas (114) you won't be able to use any.

At that compression ratio, on 93/94 octane street gas it's bound to detonate.

The only other alternative would be alcohol.

 

Assuming 114 octane...

I am running 93 octane now with no detonation.....I know that the compression is a bit high for nitrous but what is the absolute limit?

 

There is no limit with the right gas. You can run 17:1 or 7:1. If you are running 93 right now, then you are fine. 11.5:1 is not a lot of compression for a street car. Just be conservative on the timing retard, and run the fuel jets on the rich side. Nitrous likes compression. Your headgasket will be your safety valve if you push it too high. Anything over a 150 shot you can run a mix of 110 leaded and 93 unleaded.

 

Coulda fooled me...

 

I would stay with about no higher than a 250 shot. JE will probably tell you 200, some go as high as 300 with SBC's and competition guys might go 500 on 13 or 14:1 with JE's even. your ring gap is important here. how much did you give? alot is good.

 

Do you have aftermarker rods? if not I would not be going more than 150.

 

Um...good point

 

Bowtie 4-bolt block, Lunati pro-mod rods, lunati forged crank, JE forged pistons......

 

Unless you run straight Racing gas you're going to destroy all that nice $$$$ bottom end stuff. even with moderate ampounts of NOS

Detonation WILL!!! destroy any Brand or quality of stuff.

A true 11.5:1 is too high for a carbed motor on street gas with full timing. Add NOS You're looking for a disaster. A EFI Motor will only tolerate a slight bit more if any.
Many claim to be able to run that kind of cr but I'll bet that over rich mixtures, retarded timing, knock retard, Constant AFR and Timing tweeking and BS are factors.
Try a test for your self. Fill up with high octane gas.
Dyno or track test the car with full ignition timing,12.5:1 AFR and no knock retard, if it goes faster or makes more horsepower,,, ya needed the octane. Very hard to reinvent the wheel.
But easy to fool yourself.
If you can afford all the good bottom end stuff then you can afford good gas. No excuses.

You're "bulletproof bottom end" may last slightly longer under detonation then cheap stuff but will die the same firey death
sooner than you'd like of you abuse it.


You can run high compression and nitrous but not on S***T
gas.

end of story....

 

11.5:1 383, cast crank, stock rods, and hitting it with 250 and run Mobil gas with a little 110 mixed in. I have been doing it for 4 years also. If your fuel system can keep up, 11.5 can work. My motor is street driven and highway driven, so 11.5 is NOT to much for the street. Your choice of cams has a lot to due with the type of fuel you will need. A cam with a bunch of overlap will bleed of pressure and help it live on lessor gas.

Mark

 

high octane fuel with high compression nitrous motors is a must.

 

My friend has an S10 running a 355 with about 11.7:1 compression with aluminum heads and a comp cams nitrous hp cam (forget which one off the top of my head). He runs 93 octane and hits it with a 200 shot all day.

Oh yeah forgot to mention he has an independent fuel system just for the nitrous that he runs race fuel in Maybe that could be your solution rather than having to waste expensive race fuel while just cruising around town.

 

that is an awsome idea Ive done it before.

 

hehe cool man.

ok im gonna do some nitrous in the spring, after i get all the other damn problems with the motor fixed. It needs new rings again, its getting total seal gapless rings this time....golens ****ed up my bores or something and the damn rings never seated the thing burns oil like a **** and its blowing have the power into the crankcase.

anyways, with a timing retard controller and some good fuel im gonna hit it with about a 200 shot i think. the bottom end could handle more but i dont wanna pull too much timing out or strain the thing more than i have to.

it has a callies 4130 crank, manley sportsmaster h-beam rods, JE flat top pistons with AFR 210cc heads and about 11.5:1 compression.

any suggestions? im not a nitrous pro by any means