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View Full Version : Ignition control methods for nitrous


guitaraholic
11-16-2007, 03:38 AM
After doing a bit of research, I've learned that most people use MSD to retard the timing for nitrous injection. I think they cost near $300 (please correct me if I'm wrong). For $100 more I can get fuel and spark control from AEM (if its yet available for the SR).

Is there any other method to control ignition timing without dumping $300-$400? I know its not that expensive, but it kind of is for something I might only use 5 or 6 times a year. I plan on running between 75-100 wet shot. I got a dry shot system for cheap ($125), and will convert it to wet before installing. I don't plan on using it very much at all, maybe against a few of the V8's I come against. Yes, I know about the supporting mods for that kind of power (ie clutch, lsd, fuel pump ect)

Here's my current engine setup

- S14 Sr20det (stock T28)
- FMIC (HDi)
- Full 3" Exhaust
- Z32 Maf
- 550 Injectors
- Chipped ECU
- Stock Fuel Pump (upgrading in a few days)
- Stock FPR (do I need to upgrade?)

I am getting my car tuned after the fuel pump so I am estimating around 260hp, with a 75-100 shot, it would bring it close to 330-360.

Thanks for all your inputs.

RedtopTech
11-17-2007, 09:41 AM
With my t25 redtop i have gone through 6 bottles with a 75 shot wet. You simply need to take out 1 degree of base timing with the CAS per 50 shot. Tobe safe i back it down to 12.5-13 degr. BTDC. This has gotten me 11.8's in the quarter. The only issue you will run into with a larger shot is wastegate flow. The stock wastegate wont be able to divert enough exhaust gas from the turbine which will cause over boost. Good luck!

johngriff
11-17-2007, 09:51 AM
With my t25 redtop i have gone through 6 bottles with a 75 shot wet. You simply need to take out 1 degree of base timing with the CAS per 50 shot. Tobe safe i back it down to 12.5-13 degr. BTDC. This has gotten me 11.8's in the quarter. The only issue you will run into with a larger shot is wastegate flow. The stock wastegate wont be able to divert enough exhaust gas from the turbine which will cause over boost. Good luck!

Seriously. Go F yourself with this advice. NEVER EVER EVER CHANGE THE CAS TIMING.

Seriously what F :mrmeph: ?

Cas timing always = 15. Change elements of the ems from there, never by altering the cas or tps to suit whatever screwed up mod's you are attempting.

Now to the OP:

AEM FIC or Emanage Ultimate will NOT be a waste of money by any means. Even "off nitrous" the amount of HP and TQ you are going to pick up by an HOUR of dyno time and load tuning your ignition map are going to be very impressive.

Spend another hour on the dyno on the bottle tuning a "map B" for ignition and fuel and you will be sitting pretty. But, constantly altering the mechanical state of the cas and tps will only get you into more trouble, as you will be changing the whole fuel and timing map at UNQUANTIFIABLE Variants.


RAWR, and good morning (time for breakfast)

smelly240
11-17-2007, 05:16 PM
i love your fire :) I agree leave the cas alone - tune ur car.