Dry tunning help

[chevpower]

I am new at tunning and i am not the one tunning the car that i am asking help for but i have a few questions to help me understand.

My friends car was tuned today but a well known tunner when he was done with his NA tune We tried the dry out but it went lean right away and stayed to lean to run it. This dry kit has been on this car for over a year working fine but a spun rod bearing took out the 346 motor he replaced the motor with a 383 small bore ls1 5.3 heads big cam and 90mm intake and TB every thing else is the same all the way down to the nozzel placement,

Ok here is where i'm puzzled after leaving the dyno i down loaded his new tune and compared it to his old. The VE tables where exactly the same wouldnt they have changed from the two motors being so different? And the PE tables where way off the cammanded AFR at 4800 RPM was 13.7 and 14.06 at 6000 and above shouldnt the be closer to 12.8-13.0 and then the VE tables be adjusted to get the AFR we are looking for 12-8 to 13.1? Would this cause a problem with the fueling for the dry like this? the cammanded AFR at 4800 was 13.7 the actual AFR on the dry at 4800 was 13.9

[joecar]

Chev,

Have you seen this: http://forum.efilive.com/showthread.php?t=2599

The little I know about N2O is that rich is good and lean is fatal.
You need richer than what you said (as much as 11...);
someone with N2O experience can chime in here.

TTT

[Black02SS]

I am new at tunning and i am not the one tunning the car that i am asking help for but i have a few questions to help me understand.

My friends car was tuned today but a well known tunner when he was done with his NA tune We tried the dry out but it went lean right away and stayed to lean to run it. This dry kit has been on this car for over a year working fine but a spun rod bearing took out the 346 motor he replaced the motor with a 383 small bore ls1 5.3 heads big cam and 90mm intake and TB every thing else is the same all the way down to the nozzel placement,

Ok here is where i'm puzzled after leaving the dyno i down loaded his new tune and compared it to his old. The VE tables where exactly the same wouldnt they have changed from the two motors being so different? And the PE tables where way off the cammanded AFR at 4800 RPM was 13.7 and 14.06 at 6000 and above shouldnt the be closer to 12.8-13.0 and then the VE tables be adjusted to get the AFR we are looking for 12-8 to 13.1? Would this cause a problem with the fueling for the dry like this? the cammanded AFR at 4800 was 13.7 the actual AFR on the dry at 4800 was 13.9

I'd personally have it retuned somewhere else. If the PE table was setup like you mention, and he was around 12.8-13.1 on the dyno then other tables are off. This may play a small part on the fueling for the nitrous. Also, depending on the setup, you may be out of fuel when on the spray or may have to retune for the N20 and have 2 separate tunes.

[Highlander]

Check fuel pump

[chevpower]

Just an update on this problem

I retuned the car for him, I corrected the VE tables well the best that i could and also corrected the PE tables we ended up with 12.2afr to peek tq and 12.8 at peek hp well now we turned on the dry for a try and it worked it fuel between 11.3 to 12.0 across the board ened up making 604hp at 697tq on a 125 shot dry.

[Highlander]

Nice... Congrats.