PREDATOR-Z

I know this will seem awkward but here goes:

I ordered a programmed PCM and I think that it came with 16* timing for WOT (done for boost by mistake), still to be confirmed.

The question is: what would be the effects of shooting 175 dry if AFR is OK?
Does pulling so much timing on N2O have any other effects beside loss of power?

thanks,
Mark

dug

iTrader: (10)

I heard it can burnup exhaust valves.

Nitro Dave's Nitrous Outlet

iTrader: (25)

Pulling to much timing can be just as bad as not pulling enough. Every car is different so its hard to guess exactly what the timing needs to be at.A mail order tune can get you close but its not as good as monitoring the car and adjusting it this way.On a car with a power adder it is more credical than a NA tune.We use Moe Baily for all of our tunning.He is very Knowledgeable.His number is 254-644-2656.You may want to give him a call.
Dave

Ben R

Too little timing will hurt you. Do you know how to read a nitrous spark plug?

PREDATOR-Z

Ok drove the car around today,
Normal driving is normal 14.7/.8 AFR stoich.
At WOT it is 11.7

So, I'm almost convinced it is tuned for a STS system.

Now 16* timing, 11.7 AFR (prolly higher under N20), 98 octane gas with a 175 shot dry, should I do it or not.
Could it handle 1 run at least?

Last race of the season, 2 round race (I'm ranking 3rd in my division) 1/4 mile.

Ben R

Spray it, cut it, pull the plugs, and see for yourself. Spark plugs don't lie.

PREDATOR-Z

King,
Could you please be a little more specific!

Cam is a 224/220, .581/.581 116+0
heat is horendeous, like 110+ degrees, humidity is 80% at least at sea level.

Ben R

Take your car out and spray it through 2 gears. As soon as you let off the gas, throw the car in neutral and turn the engine off. Then you'll need to pull over and pull your spark plugs. This is how you check to see how on edge your system is. You'll be able to see how rich/lean you are and how much heat is being generated in the combustion chamber. Like I said, spark plugs don't lie.

Robert56

iTrader: (2)

See the current spark plug reading thread for more insight.

PREDATOR-Z

Well I did it, although it didn't net me into the 10's (too much retard, lost at least ~30rwhp estimate)

11.234 @ 121.13 mph/ 1.566 60'/ 7.2 1/8th- 150 shot dry (best)

I wasn't displeased. The removal of front sway bar and bolt on relocation brackets worked superbly.
That FLP tranny never ceases to ammaze me how quick it shifts.

Pulled the plugs on # 1 and #2, definite signs of richness but no damage. I was a fun night.

Got 5th overall and a whopping $100 consolation prize. LOL, beers were on me tonight.

Ben R

Can you post high-resolution photo's of the plugs? How does the timing ring look?

Robert56

iTrader: (2)

Congrats, nice time, and will be better once it's fine tuned.

PREDATOR-Z

yeah, it was confirmed that this pcm was tuned for STS boost at 5 psi.

No races till september, so I will put heads on and a more nitrous friendly cam (I'm thinking FM9), heads is a toss between TEA & PRC, 5.3 L

Car is race only now so we shall see. Goal is mid to low 10's on Nitrous, stock LS1 shortblock.

koolrayz

iTrader: (26)

nice times concidering the tune
glad to see your back on the road

PREDATOR-Z

Thanks Koolrays,
I found a low mile shortblock out of a wrecked Lumina SS (same as GTO), so for $1500 I couldn't pass it up. This thing was mint, hardly any carbon on the slugs. ~7K miles.

I ordered some PRC 5.3 stage 2.5, so I got some work to do for the Summer.

How is your 408 runnin'?