Jetting & Timing

[JiM P 2001]

I'm going to yank some timing out of my car before I spray a massive shot on it. Anyone have the general rule of thumb for timing to shot ratio?

I was planning on pulling 2* for every 50. I'm starting at a 100 shot and working my way up until I reach my desired E/T and trap, or the thing pukes it's rods all over the track. Sound about right?

[Rhunter]

Quote: Originally Posted by JiM P 2001

I'm going to yank some timing out of my car before I spray a massive shot on it. Anyone have the general rule of thumb for timing to shot ratio?

I was planning on pulling 2* for every 50. I'm starting at a 100 shot and working my way up until I reach my desired E/T and trap, or the thing pukes it's rods all over the track. Sound about right?

Is there knock? I've never sprayed 100, just wondering how much KR you are seeing.

[neonmarine]

What do you have to monitor Knock? and what are you using adjust timing?

[JiM P 2001]

I haven't sprayed it yet. I'm using a scan gauge to keep an eye on knock and will be using SCT to re-flash. I'll be using NGK 2 step colder plugs and VP C16 fuel when I'm spraying.

Stock turbo, stock engine, 22psi spike, using n2mb n2o control off wot box

[rrmike1]

You really don't need the C16. I've been spraying a 50 shot on my mods with no knock whatsoever. Don't take out any timing unless you're getting knock...

[neonmarine]

Quote: Originally Posted by JiM P 2001

I haven't sprayed it yet. I'm using a scan gauge to keep an eye on knock and will be using SCT to re-flash. I'll be using NGK 2 step colder plugs and VP C16 fuel when I'm spraying.

Stock turbo, stock engine, 22psi spike, using n2mb n2o control off wot box

I've seen, in person, couple of guys spray a single fogger 75 shot with no problems. Many claim the same over the net and on the forums. Drop your spike down to 19ish and have fun. C16 is pointless.

[neonmarine]

BTW, that gutted cat is more of a restriction now then when it was stock. I'd do something about that. Just my 2 cents.

[never2muchboost]

ive sprayed 100+ on a fogger lol

[JiM P 2001]

Next mod is a maxxfab 3" SEE and O2 housing... I've been cheaping out on exhaust for 2 years now...

I'm gonna run C16 in the car because I'm starting out on a 100 shot. I'm going to increase the shot in the staging lanes at the track until I reach my goal for my setup. It will probably end up being a ~150-180 shot when it's all said and done.



Enjoy staring at my broken dipstick (handle snapped off when I went to pull it out yesterday, WTF!) and yes, I know the hose from the valve cover to intake is ripped.

[neonmarine]

Looks good....Is there anyway you can do some AFR testing on a smaller shot before the track date? Once you confirm you're good, uping the jetting will be a snap. But if your AFR's are off on the small stuff, we all know what will happen on larger shots.

I found that the air/fuels stayed true, once the baseline was tuned. All you have to do after that is reach for the nexted size up!

Also, using a dyno isn't just for number hunting. The first time I sprayed on the rollers, my #3 cylinder went lean due to a leak on the fogger to fuel line connection. Lucky for me, I was standing right there, watching and immediatly shut the dyno operater down to fix the leak.

[Rhunter]

Jim,

That is a friggin sweet set up! !

The time to beat is 11.3.

The fastest time this year on stock turbo & nitrous is 11.5

Have fun boys

[JiM P 2001]

Quote: Originally Posted by neonmarine

Looks good....Is there anyway you can do some AFR testing on a smaller shot before the track date? Once you confirm you're good, uping the jetting will be a snap. But if your AFR's are off on the small stuff, we all know what will happen on larger shots.

I found that the air/fuels stayed true, once the baseline was tuned. All you have to do after that is reach for the nexted size up!

Also, using a dyno isn't just for number hunting. The first time I sprayed on the rollers, my #3 cylinder went lean due to a leak on the fogger to fuel line connection. Lucky for me, I was standing right there, watching and immediatly shut the dyno operater down to fix the leak.

I'm gonna end up smoothing out the AFR on the S2 computer and spraying on top of it. Right now I'm running a 255 with a 10awg rewire, bottle neck fix, aeromotive FPR, -6 Feed, -4 return, 58psi static, no boost reference. If I do the boost reference, that's gonna bring the fuel pressure up to 80psi at peak boost, isn't that a bit much? I just want to get this right the first time. Any tips on fueling, etc would help a lot.

Quote: Originally Posted by Rhunter

Jim,

That is a friggin sweet set up! !

The time to beat is 11.3.

The fastest time this year on stock turbo & nitrous is 11.5

Have fun boys

Thanks man! I'm trying to shatter the record and get a 10 second pass on a stock engine/turbo. Nothing touched from the throttle body to the turbo, no port work, etc.

[neonmarine]

I ran mine with a boost reference to a Aeromotive FPR 1:1. 22psi spike also. My advantage was a DTEC map just for spray. I had the "hit" leaned up, (too rich) and smoothed out the rest of the way. But that was my method. It worked. Hope this helps.

[neonmarine]

BTW, I had a 255lph BN fix, -8 feed, -6 return with a Boomba rail. You have a better system than me.

[JiM P 2001]

I guess this is my concern, and correct me if I am wrong, because this is my first car with boost, as well as with nitrous.

If my static stock fuel pressure is 58psi, and I run 22psi of boost, the 22psi of boost will be pushing back the fuel with 22psi of force.

Therefore, 58 - 22 = 36psi

So, without running a boost ref off my aeromotive FPR, I should jet the nitrous as if the car was only making 36psi of fuel?

I assume that the aeromotive FPR is a 1:1 ratio increase? +1psi of boost = +1psi of fuel? Isn't an 80psi spike a lot of pressure to send into the injectors? I was told by the guy tuning my car that it's dangerous to run that much FP because the injectors can lock up...

I pretty much have no clue of what I'm doing. I need to go back to RWD carbbed small blocks..