Timing Retard with N02

[CNE]

My tuner said 2 degrees for every 50 hp shot. I was at the track the other day and talked to a guy who owns a speed shop. He was there with one of his customers with a Sierra 5.3 RCSB running a 100 hp Zex kit and 13.50's on street tires with CAI, shorty headers, and tune. He said he doesn't pull any timing. Another person said only about a degree for 125 shot. So, what is everybody else doing? I don't want to hurt anything.

[zippy]

If you're playing it safe, I agree with 2 degrees for every 50hp shot of nitrous. Keep in mind though that if your not tuned perfectly on your N/A tune that you will have room to run juice without touching the timing. My recomendation is to keep your tune normal and just run race fuel when you want to spray. Unless you're running a big shot, race fuel alone should do it. I've seen a 150 shot with 28 degrees of timing on an LQ9 with a cam, but that was with 3 gallons of race fuel added. If you're running a 125 shot, I'd say go for an 11.2:1-11.5:1 afr on 24-26 degrees of timing. You can achieve this pretty easily without spending alot of money on a timing tuner box if you have your tuner set you up with the amount of retard that you want in a specific spot of the afr table. Buy a resister from Radio Shack like you find on Ebay for the IAT sensor and take a reading of the number the pcm see's. You can just have a jumper at the IAT sensor and run the resistor when you want to run the spray at the track. If the resistor shows the pcm say 30 degrees, you set the timing to -X degrees right there. You could even have different resistor for different amount of retard.

[thomp62301]

i have mine retarted 4 degrees with a 150 shot

[CNE]

i have mine retarted 4 degrees with a 150 shot

 

 

I see your best ET is well into the 12's. What do you run off the bottle? I'm just trying to get an idea of what to expect when I spray.

 

 

 

Zippy, I see you do a lot of tuning and I would guess most of it is mail order. How do you achieve accurate tunes without ever touching the vehicle? My tuner found issues after tuning mine. I had taken it back for him to tweak after installing the Yank 3200 and he logged some data and found the timing not what he thought we had and some KR down low, so he reset the timing to 28 degrees and added some more fuel down low. We have talked about meeting at the track to log some runs but haven't gotten together yet. So with him actually having the vehicle and still having issues, how do you do it? By the way, how much do you charge? If we can't work out the bugs, I may just get with you instead.

[Sum 1]

I'm now at 24' with a 100 dry shot and A/F at 12 w/no KR.

[thomp62301]

I see your best ET is well into the 12's. What do you run off the bottle? I'm just trying to get an idea of what to expect when I spray.

Zippy, I see you do a lot of tuning and I would guess most of it is mail order. How do you achieve accurate tunes without ever touching the vehicle? My tuner found issues after tuning mine. I had taken it back for him to tweak after installing the Yank 3200 and he logged some data and found the timing not what he thought we had and some KR down low, so he reset the timing to 28 degrees and added some more fuel down low. We have talked about meeting at the track to log some runs but haven't gotten together yet. So with him actually having the vehicle and still having issues, how do you do it? By the way, how much do you charge? If we can't work out the bugs, I may just get with you instead.

 

 

i never ran it off the bottle, so i'm not sure of the times with my current mods. bone stock i ran 15.2 and then ran 13.2 after the nitrous install. i've done a couple more mods since i ran 12.63. i'm actually thinking of going to the track friday night and i'm hoping to break into the 11's

[Krambo]

You guys running nitrous on a non supercharged engine can run a reverse IAT adder table as well. You can make it so that when you spray, the IAT' table will pull a couple of * even though it is getting colder (typically you add * as the IATs get colder). I haven't sprayed before so this is assuming that the IATs go way colder than ambient on a shot. This would allow you to run full timing when not spraying and the PCM can do its job with out a reflash or a resistor and operate safely. Should be pretty easy to figure out, a couple of logs when running spray and a couple of logs running N/A. You can scale the IAT adder table linear off that.

 

Just shooting out some info...

[PladdPezzPunk]

You guys running nitrous on a non supercharged engine can run a reverse IAT adder table as well. You can make it so that when you spray, the IAT' table will pull a couple of * even though it is getting colder (typically you add * as the IATs get colder). I haven't sprayed before so this is assuming that the IATs go way colder than ambient on a shot. This would allow you to run full timing when not spraying and the PCM can do its job with out a reflash or a resistor and operate safely. Should be pretty easy to figure out, a couple of logs when running spray and a couple of logs running N/A. You can scale the IAT adder table linear off that.

 

Just shooting out some info...

 

almost, but not that simple, you should be injectecting after the IAT so it should never really see the difference. The only way to have full power off the bottle is to run 2 tunes. via timing box or run a switch run in with the nitrous switch to switch tunes in the PCM. EFI Live allows for this don't know about HP tuners though. Anyone on HP tuners done this?

[Krambo]

almost, but not that simple, you should be injectecting after the IAT so it should never really see the difference. The only way to have full power off the bottle is to run 2 tunes. via timing box or run a switch run in with the nitrous switch to switch tunes in the PCM. EFI Live allows for this don't know about HP tuners though. Anyone on HP tuners done this?

 

 

I see your point. Now, I have a Radix with the IAT sensor in the manifold. If I was to run nitrous through the rotors of the Radix, I should in theory be able to do this IAT adder reduction in spark. Yes, under load the radix will be increasing IATs and the nitrous may only keep the temps even or decrease a little so it may be harder to do this. Anyone know how much nitrous cools off an intake charge N/A and then Supercharged (shot size dependent)?

 

Ambient temps would also have a big impact as well I assume.

[PladdPezzPunk]

I see your point. Now, I have a Radix with the IAT sensor in the manifold. If I was to run nitrous through the rotors of the Radix, I should in theory be able to do this IAT adder reduction in spark. Yes, under load the radix will be increasing IATs and the nitrous may only keep the temps even or decrease a little so it may be harder to do this. Anyone know how much nitrous cools off an intake charge N/A and then Supercharged (shot size dependent)?

 

Ambient temps would also have a big impact as well I assume.

 

it's a little more technical than that. your right though. It would take me pages and pages to explain the theory but basically nitrous in a boosed motor will act like adding more boost. escentially everything will run cooler allowing the supercharger to run more efficiently. but you wouldn't want to only adjust the timing with a boosted motor.

[Sum 1]

You guys running nitrous on a non supercharged engine can run a reverse IAT adder table as well. You can make it so that when you spray, the IAT' table will pull a couple of * even though it is getting colder (typically you add * as the IATs get colder). I haven't sprayed before so this is assuming that the IATs go way colder than ambient on a shot. This would allow you to run full timing when not spraying and the PCM can do its job with out a reflash or a resistor and operate safely. Should be pretty easy to figure out, a couple of logs when running spray and a couple of logs running N/A. You can scale the IAT adder table linear off that.

 

Just shooting out some info...

 

I only dropped 5' IAT on a 100 dry shot at 900psi. You can also play around with nozzle direction/distance relative to the MAF to influence A/F. It's better to let the MAF go a little rich anyway to avoid KR and sacrifice power while spraying.

I'm just running 4' less timing all the time now while NA + the colder TR6's. Overall, my mpg has increased 10%, there's no knock and no concerns of detonation, just playing it safe.

 

And yeah, superchargers with nitrous are a lethal combination. Make sure the heads are torqued down!

[CNE]

i never ran it off the bottle, so i'm not sure of the times with my current mods. bone stock i ran 15.2 and then ran 13.2 after the nitrous install. i've done a couple more mods since i ran 12.63. i'm actually thinking of going to the track friday night and i'm hoping to break into the 11's

 

 

So realistically if I'm running 14.25 or lower off the bottle, I should easily see some 12's on the bottle with 100-125 shot right?

[thomp62301]

So realistically if I'm running 14.25 or lower off the bottle, I should easily see some 12's on the bottle with 100-125 shot right?

 

 

i would think you should see 12's

[gsxr-red-1000]

i went 14.20 all motor with cai ,stock exhaust with flowmaster muffler, throttle body spacer which is tapped with wet shot,. went 12.85 at 106mph with 125 shot. not bad