I will add more fuel with my boost a pump and reduce timing. Time to add that second wet stage.. 
Cold weather tuning questions???
Thread Starter
Joined: Nov 2001
Posts: 8,259
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From: Valrico, Florida
Cold weather tuning questions??? Last night I messed around with my nitrous on the dyno. Two months ago a 125 shot put out some good #'s in 80 degree weather and 78 percent humidity with 3 degree's of timing retard. I sprayed the same shot with the same timing retard and last night I received detonation. I was told that because of the colder temps the air is denser thereby increasing cylinder pressure and that I would need to decrease my base timing as well. Well I ended up reducing timing to 5 degree's and no KR, but I made almost the same gains as in the summer months. Now all of this was just on pump gas. I am sure if I had a race gas mix or straight 100 octane I would be able to run with very little if any retarded. My static compression is between 11.7:1 and 11.9:1. I think closer to 11.9:1. Maybe my 250/257 lsa 112 is not big enough
Any thoughts????
Any thoughts???? Leaner In colder weather yes the air is denser causing the A/F to run leaner, This is why cars make more power in the winter time becuse of the leaner mixture. When the heat comes back the A/F will get richer so tune accordingly by adding more fuel or reduce the timing or a little of both, whichever gives you the most safest power....
Thread Starter
Joined: Nov 2001
Posts: 8,259
Likes: 4
From: Valrico, Florida
Also, I just thought of something. The last time I sprayed it I had the cutouts closed. This time I had the cutouts open which caused a much leaner condition.
Your MAF and IAT will compensate for colder temps. I have seen this on many cars. The MAF will read higher lbs/min in cooler weather.
Do you have a seperate program for that dry shot? If not your A/F is gonna be lean re-guardless...
Do you have a seperate program for that dry shot? If not your A/F is gonna be lean re-guardless...
Thread Starter
Joined: Nov 2001
Posts: 8,259
Likes: 4
From: Valrico, Florida
Originally Posted by Billiumss
Your MAF and IAT will compensate for colder temps. I have seen this on many cars. The MAF will read higher lbs/min in cooler weather.
Do you have a seperate program for that dry shot? If not your A/F is gonna be lean re-guardless...
Do you have a seperate program for that dry shot? If not your A/F is gonna be lean re-guardless...
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Ahhh, Boost A Pump, the Band Aid fix.....
I have a NOS 5177 Dry Kit on my car and the only way to get your A/F right is to use a seperate tune for N20 and tune it on the dyno. With your 408ci, your gonna need some very large injectors with that size of dry shot....
I have a NOS 5177 Dry Kit on my car and the only way to get your A/F right is to use a seperate tune for N20 and tune it on the dyno. With your 408ci, your gonna need some very large injectors with that size of dry shot....
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Verdad Gallardo Thread Starter
Joined: Nov 2001
Posts: 8,259
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From: Valrico, Florida
Originally Posted by Billiumss
Ahhh, Boost A Pump, the Band Aid fix.....
I have a NOS 5177 Dry Kit on my car and the only way to get your A/F right is to use a seperate tune for N20 and tune it on the dyno. With your 408ci, your gonna need some very large injectors with that size of dry shot....
I have a NOS 5177 Dry Kit on my car and the only way to get your A/F right is to use a seperate tune for N20 and tune it on the dyno. With your 408ci, your gonna need some very large injectors with that size of dry shot....
You dont need seperate tunes. With the dry shot you can add timing retard and fuel into the program while on dry nitrous only. Then under normal WOT you will staill have your more agressive NA tune. Jeremy Formato of Formato's Fasterproms has been doing it this way far some time and it works well. My car would be at 12.8 to 1 on motor and when I would spray the 300 shot dry it would retard timing 10 degrees and AF would go to 11.8 to 1 or so. Works damn good.
Originally Posted by VINCE
I have 42lb injectors. That should be more than enough. The only time my car leaned out is when I opened the cutout. The next stage is a wet kit. So I will be able to control my a/f easily. The boost a pump does wonders
Your have 42lb injectors for your setup??? Are they SVO 42lb? If not you are on the edge of hitting 100% duty cycle when you are running N/A. Then you are using a 100 dry shot on top of it???
If you have SVO 42lb injectors you'll be fine, if not your f'd....
Just trying to help...
Originally Posted by 383LQ4SS
You dont need seperate tunes. With the dry shot you can add timing retard and fuel into the program while on dry nitrous only. Then under normal WOT you will staill have your more agressive NA tune. Jeremy Formato of Formato's Fasterproms has been doing it this way far some time and it works well. My car would be at 12.8 to 1 on motor and when I would spray the 300 shot dry it would retard timing 10 degrees and AF would go to 11.8 to 1 or so. Works damn good.
Please teach me then, seriously.
A 300 Dry shot, come on, you know how big the injectors would have to be???
I've been running a 75 dry shot for 2 years now and I can see how you can have "2 different tables" for a dry N20 shot, but 2 different tables for WOT PE for a dry shot??? Thats
Last time I checked, there is only 1 WOT PE table to adjust your A/F ratio with....
TECH Addict
Joined: Sep 2003
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From: Atlanta, GA
you can just mod the table pointer of the ecm code to switch tables on the fly. oh yeah you might need a code warrior to do it but its only 68332 (sorta) not exactly the most complex ecu on the planet.
12 Second Club
Joined: Aug 2002
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From: Tampa, Fl
Originally Posted by Billiumss
Please teach me then, seriously.
A 300 Dry shot, come on, you know how big the injectors would have to be???
A 300 Dry shot, come on, you know how big the injectors would have to be???
Originally Posted by Billiumss
I've been running a 75 dry shot for 2 years now and I can see how you can have "2 different tables" for a dry N20 shot, but 2 different tables for WOT PE for a dry shot??? Thats
Last time I checked, there is only 1 WOT PE table to adjust your A/F ratio with....
Last time I checked, there is only 1 WOT PE table to adjust your A/F ratio with....
383LQ4... can you hit me with a PM sometime. We are close to maxing out the maf with a heads/cam dry nitrous car. 400 rwhp thru T400/12 bolt/steel shaft and 537 on the spray. It was a little lean though. 12.8:1 on the motor, and still 12.8:1 on spray first pull. Thru fuel at it thru the PE table richened it to 12.0:1 still made same power on the nitrous, but Id like it to be richer. Problem is with the maf, its not gettign enough enrichment via MAF alone. Im wondering if I scaled the maf table by 90% and the injectors by 90% (so it would lean out via maf and richen up via injector) it would make it run richer when the maf reading skyrockets on nitrous. Or am I backwards?
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Originally Posted by moehorsepower
In colder weather yes the air is denser causing the A/F to run leaner, This is why cars make more power in the winter time becuse of the leaner mixture. When the heat comes back the A/F will get richer so tune accordingly by adding more fuel or reduce the timing or a little of both, whichever gives you the most safest power....
