Nitrous Tuning

[Yamahaulin]

I have a question on timing with a 50 wet shot. The generally rule of thumb with nitrous is that for every 50hp take away 2 degrees of timing. Now on a turbo car i'm thinking that since i run very low timing anyway and the nitrous will cool the air charge into the engine that i won't have to take any away for just a 50 shot. Also i'm thinking that the 11.5 afr i run will probably been plenty rich since it's just a 50 shot. I have used alot of nitrous on v8 naturally aspirated cars but never on a turbo, so i'm looking for someone with experience to back up my thinking here.

 

[JayRolla]

From what I know the nitrous is mostly air so it will lean the air fuel ratio out and will want you to add some fuel. I would take timing out along the whole timing curve just to be safe. If you feel afterwards you can add some then do it, but be safe with it. I would also run a colder stage plug than normal.

 

[NOSLO2PT0]

That 50shot will net you almost 100hp at the wheels. Pull some timing out at first. If it doesn't knock, add a little back in slowly.

 

[Yamahaulin]

Will 11.5 be rich enough or should i go to 11.0? You think the br7es plug will not be cold enough? I would have thought it would be fine for a 50 shot but looking for someone that has used them.

 

[JayRolla]

Well how much boost will you be running? Remember you are running a colder stage plug for the extra boost. Now that your adding a 50 shot you may want too go colder if you have plug issues, but I would wait on that.

What fuel will you be using? Pump gas, e85, race fuel? If pump gas I would run rich around 11.0. If race fuel or e85 I would go a little leaner. But when that nitrous hits make sure its still rich as it should lean you out.

Another thing to watch for is boost spike. I would turn boost down a lot since nitrous likes to cause turbos to spike real bad when it first hits, you dont want to blow up a turbo or motor from too much boost when the nitrous hits.

Turbo cars and nitrous act a lot different than N/A cars. Turbo cars act very violent when using nitrous. Like stated a wet 50 shot can net over 100HP on a turbo car.

 

[sbiggi]

Do any of you actually run nitrous?

I have run a 100 shot with a 50trim and with my now 6152e.

My boost does not fluctuate. I have a external Tail 38mm.
With the 100shot I make almost exactly 100 more wheel horsepower. If I remember the 50 shot did net me around 60whp. This will all depend on how efficent your motor is and how much you are already pushing it with just a turbo.

As for timing, your safest bet is to tune it on a dyno. With race gas the whole add till it knocks doesnt net you the best gains. You can add to much timing and reduce power or no gains in power before it knocks.

What worked for me was not pulling just 2 degrees through the whole map. I tuned it on a dyno and the amount of timing varies through the rpm. In some spots I only pulled one degree and others 3 degrees from my race gas map.

As far as A/F. Tune with what you like and adjust timing accordingly. All really depends on what your motor likes, gas you are running and what you feel comfortable with.
I personally tune for around 11.5:1 on nitrous and racegas. For just race gas I dont mind it a little leaner if I'm running some nice gas like Q16.
I've never used it with pump gas though. I dont want to risk my motor just to make big numbers on 91 octane.

For plugs I run the same plugs I run for just race gas. I run BPR8's which has worked for me on a stock ignition with a .022 gap.

 

[Yamahaulin]

Well i run 93 daily on a T04e 60 trim running 20psi. I will try the 50 shot at 11.0 and see how knock goes with that. I really believe that 11.5 will be safe but will have to just see how knock goes, i have the timing very low around 10 so that should be ok. I can get some 116 octane for the track but $11.80 a gallon I don't want to use it all that often.

 

[sbiggi]

If you are only running 20psi on that turbo, why bother with nitrous? Turn the boost up a couple psi for another 50whp.

 

[Yamahaulin]

I've had all the nitrous parts in my garage for years with nothing to do with it, so i decided to put it on this car. Figured the nitrous would cool the air charge for some safer hp on pump gas.