View Full Version : NOS kit owners in here!!!!


Pete91
04-30-2012, 07:35 PM
I'm just curious what you jet sizes and afr's are for your size shots. I have the basics from my kit 05169 wet plate kit.
Configuration N F Configuration N F
75 41 26 175 67 47
100 51 31 200 73 51
125 55 35 225 78 55
150 63 44 250 83 59
These are the recommended jet sizes and all the ones I have ONLY UP TO A 150 SHOT. I am going to a track rental the 14th at Atco and I'm just curious to all the Nos user if they are working and what jets you guys are using for the bigger shots 175,200,225,250 ect. My car is a stock bottom end H/C/I car and I have the racetronix pump and hotwire kit. I am pulling off the rail no standalone. From reading in this section I understand the kits come jetted a bit rich. I would like to go up to a 200 shot I think the fuel pump can handle it, what do you guys have think? I have a fuel pressure gauge I will be watching like a hawk. So I was thinking of picking up 42,40,38, 67/46 for a 175 shot and a 73/50 for a 200 shot then a 48 if I have to lean out the fuel. What do guys think about these jet choices? I read in another post that 78/44 for a 200 shot was being used and that was rich do it turned out to a 35 fuel jet. I don't know what kit this was and I think it was out of a standalone because the fuel pressure was higher. Well what you guys say post up!!!!

JL ws-6
05-01-2012, 07:31 AM
Every fuel jet for the nos out, is way too big. You need to just about run the 125 fuel jet with a 150 shot, for reference. I would start playing at 100 until you have the plugs looking right before putting more then that to it, at a 100 hp level you probably won't hurt anything, so jumping uP into the 200 range right away you will probably hurt something unless this is old hat to you, but judging by your question, probably not the case? Fwiw I ran the same kit, started with the nos 150 jetting, ended up down 3 jets and up to a 65 before the tuneup looked decent, and it was still fuel heavy fwiw

JL ws-6
05-01-2012, 07:33 AM
I was using the same fuel setup you are as well fwiw, get a bunch of jets, cover everything between 30 to 40, until you have a good tuneup at a 125 to 150 level, this way you aren't tempted to just throw more nitrous jet at it to go faster

lsxTAlemy
05-01-2012, 07:51 AM
in sorry for coming in like this but ur kit
100 51 31
125 55 35
150 63 44

my kit 100 and 125 is the same but my 150 says 63n 38f ??

Fbodyjunkie06
05-01-2012, 10:47 AM
in sorry for coming in like this but ur kit
100 51 31
125 55 35
150 63 44

my kit 100 and 125 is the same but my 150 says 63n 38f ??

Every kit is different and as was said above the NOS kits are jetted RICH as hell from the start.

I will most likely be ending up with a 74N and 38F for my 200 shot tune-up once I get the small bugs out and hit it on the 62N 38F just to confirm the tune-up is showing no heat on the strap and rich still.

I started with a 62N 38F at 58psi and it got me 11.8-11.9 afr with no heat showing on the plugs and more of a fuel ring than I would like to see. Hoping the 74N 38F combo leans it out a half a point and get's me into the 12.4-12.6 afr range. Also will be pulling 4 more degrees on top of the 8 total that is already pulled out for the 62N 38F and using 50/50 race gas pump gas mix for added safety.

Lean is mean. Don't be afraid to lean it out, BUT make sure the timing is pulled back more than you would think it needed to be. When your leaning your tune-up out you always want to take away as much timing as possible without making it go dead and then add it back in slowly a degree or half degree at a time until it's where it should be, but don't chase the timing mark looking for a better number.

lsxTAlemy
05-01-2012, 11:14 AM
thanks so start with the 38 work my way leaner? my fuel pressure is at 55

Pete91
05-01-2012, 02:33 PM
Okay so I will mess around with the hundo considering I only have 4* of timing pulled, I would like to at least run the 125 shot. Should I tell my tuner to pull 9* so I can work my way up there?

Pete91
05-02-2012, 06:42 PM
I just wan this varafied pretty please..... I have 4* of timming pulled. That is okay for the 100 hit right? My nos recommended jets are 51N/31F I just pick up jets but only have a smaller size of 28. Do think this will be okay? I have the 31 in I'll see how it dose first before swapping out. I am not going to plug read right now but hopefully I can make a pass tomorrow if the weathers nice and check out the afr's. After reading all these threads if I put the 28 in and its in the mid to high 12's I'm still okay right? Don't worry I'm going to try and read the plugs this weekend being I deff won't get to make a nirous pass at the track as my car already runs 11.40's on motor with a shitty 1.68 60' no cage in the car.

JL ws-6
05-02-2012, 06:59 PM
AFR is not going to tell you what reading the plugs will. If you're not going to read the plugs I wouldn't even put a bottle in the car period. The spark plug is the ONLY thing that can tell you what's going on in the engine. Everything else is only going to give you an "idea", at best.


Changing jets, and making adjustments, without putting fresh plugs in so you can get accurate reads, again is a really good way to blow the motor up. 4 degrees pulled out would normally be a good start, but from what n/a timing are we talking about? Depending on where the n/a tune is you may, or may not need to pull more then that.

Pete91
05-02-2012, 07:26 PM
AFR is not going to tell you what reading the plugs will. If you're not going to read the plugs I wouldn't even put a bottle in the car period. The spark plug is the ONLY thing that can tell you what's going on in the engine. Everything else is only going to give you an "idea", at best.


Changing jets, and making adjustments, without putting fresh plugs in so you can get accurate reads, again is a really good way to blow the motor up. 4 degrees pulled out would normally be a good start, but from what n/a timing are we talking about? Depending on where the n/a tune is you may, or may not need to pull more then that.

I didn't say wasn't going to read the plugs at all I said I wasn't going to read the plugs if I make one test pass. I live in queens Ny. The highways over here don't exactly have big shoulders to pull off on by me. I have to take a hour drive out to the island for a safe place to do that. I'll prob end up doing it this weekend anyway so I can pull the plugs.

Pete91
05-02-2012, 08:49 PM
Btw I'm at 24* of timing

JL ws-6
05-03-2012, 01:49 PM
I'd pull 6 to start just to be safe. Talk to Intenss, he probably knows somewhere you can "test" the car out that way he's not too far from you.

Pete91
05-03-2012, 04:50 PM
Ok I'll hit him up I know who your talking about. Thanks

Fbodyjunkie06
05-03-2012, 07:09 PM
When leaning any tune-up out more than the recommended jetting on the jetting card, always pull more timing when going to a smaller fuel jet.

Reason being is when there is more fuel in the chamber to help cool the strap heat doesn't show as much on the strap and thus can hide the true timing mark.

When you begin to lean it out, more heat is shown on the strap and the timing mark can and most likely will make a move towards the bend of the strap when this happens if the timing is left the same as it was on the richer fuel jet.

This is why it is very important to be conservative with the timing and pulling more timing even when your not going up in nitrous jet size as the heat from leaning it out will move that timing mark closer to the bend or past it.

Reading the plug is the only way you can see this for yourself.

I learned this with my turbo car. I kept trying to figure out why as I leaned it out more and more and keeping the timing the same that the timing mark kept moving further and further towards the bend. I had heard that this timing "number" I was running was acceptable, but again you have to read the plugs to truly see what your changes are doing and not going on blind faith.

Good luck.