Trying to tune a car with (guesstemate) 6 psi. A friend bought this car with everything allready done to it...

Have tuner cat and a Ed Wright tune....don't know many details on the car,

Forged 355
Eric Bradley heads and intake
Don't know exact on cam....22x/22x of the shelf blower cam
Don't know the injectors, pretty sure they are 24's
Paxton blower...pretty sure this is one of the kits


A/F goes off the charts at 10:1 at 2500 rpm.....have not taken it above 4k

 

In the % change to air/fuel ratio vs rpm at WOT table, what kind of numbers are you showing from 2400rpm on up? Sounds like you need to start taking away from that point on up depending on what your reading in the higher rpm's.

Ken R.

 

I am the guy that Mike (mdacton) was trying to help last night while I was at the dyno ( thanks again Mike). The car was poping and so-on the whole time so I have something wrong in the tune all the way though. When I get to the computer I will post what everything in the table says. Thanks for the help Buck

 

That's not enough injector for any amount of boost, but just look in the cal and see what they are set up as.

 

if it was a paxton kit, it should have a "paxtamap fueller" which is the same as a Carroll Superfueller. Look for a throttle body plate with 3 injectors on it. If so, then find the box and you can tweak the fuel added under boost by adjusting the rotary dials behind the front panel (2 torx screws).

http://www.blowerworks.net/superfueler/index.html

 

Thanks for the help guys. Here is some more info. I have 42lbs inj. I took out the paxtamap because it was also making it run rich and I am trying to do it by tune.
400 1.2
800 1.2
1200 1.2
1600 1.2
2000 1.2
2400 1.2
2800 1.2
3200 1.2
3600 3.1
4000 6.3
4400 12.5
4800 16.4
5200 22.7
5600 25.0
6000 25.0
6400 25.0
6800 25.0
This is my chart for %change to A/F at WOT

If you see something wrong let me know.
I am also having trouble at idle with it poping and surging. Not able to find a solid idle. If anyone can help w/ that it would be awsome. It did well at part and 3/4 but idle and WOT were crap. Thanks for the help! Buck

 

Just looking at it, its definitly set up to keep adding more fuel as rpm's rise. Heres an example of some of my old tunes. 1st is H/C N/A 350 30# SVO injectors & stock fuel pump. 2nd is 383 on 8psi with 60# Seimens injectors and 255 in tank along with a NOS booster inline pump. 3rd is 383 on 14psi with 60# Seimens & upgraded twin in tank 255's. The N/A tune ran at 13.0:1 A/F. The 2nd on 8psi ran at about 11.9:1 but started leaning out fast as rpm's and boost built up. And the 3rd ran at 11.5:1 right up to 6200rpm.

1st
400 4.7
800 4.7
1200 -0.8
1600 -0.8
2000 0.8
2400 0.8
2800 0.0
3200 -2.3
3600 -1.2
4000 -0.4
4400 0.0
4800 -1.2
5200 -2.3
5600 -6.3
6000 -6.3
6400 -6.3
6800 -6.3

2nd
400 12.9
800 12.9
1200 12.5
1600 11.3
2000 11.7
2400 12.1
2800 14.8
3200 16
3600 18
4000 21.5
4400 23.4
4800 23.4
5200 21.9
5600 18
6000 17.2
6400 16.4
6800 14.5

3rd
400 4.7
800 4.7
1200 3.9
1600 3.9
2000 3.5
2400 3.1
2800 2.7
3200 2.3
3600 2.0
4000 -3.5
4400 -3.9
4800 -3.5
5200 2.3
5600 5.5
6000 8.2
6400 8.2
6800 8.2

Oops, i just had to edit... Saw you had 42's in there. What might have happened is there was already fuel added for previously smaller injectors but not changed when 42's went in. Should also verify the injector constant is right for the 42's also. I'd try taking away from those numbers from 2500 on to start leaning it out and see what happens...

Ken R.

 

I have 42's w/ a 255pump. Thanks for the help!

 

Yeah, just saw that, so did a quick edit.. Oops! Guess i'm not paying attention today...

Ken R.

 

Buck did you change the constant to a 42 injector? and what press you running?

 

yep I changed all that stuff for the inj. Ed Wright did the tune and unlocked it and when he did that it might have changed all that stuff around. Who knows but I will try it next time I go down to the dyno. Thanks guys! Buck

 

Here is the A/F you are commanding with those values.
400 12.58561644
800 12.58561644
1200 12.58561644
1600 12.58561644
2000 12.58561644
2400 12.58561644
2800 12.58561644
3200 12.58561644
3600 12.38416175
4000 12.05906481
4400 11.47540984
4800 11.13636364
5200 10.62906725
5600 10.45519203
6000 10.45519203
6400 10.45519203
6800 10.45519203

 

Could you tell me what the equation is to calculate that and is that based off 42 lbs/h at 40psi or off the stock 43psi of a camaro? Thanks Buck

 

(1 - ([# in Temp Table] + [# in RPM Table])/100)*14.7
or
14.7/(1+Number in the Cool temp table/100+ number in the RPM table /100)

Either formula should work. I have a nice Excel spread sheet that does it for you. All you do is copy and paste the numbers from your table into it. If this forum allowed attachments, I'd post it here. I could email it to you if you post your email address, or I could email it to someone that could host it.

 

The fuel pressure the injectors are rated at would be scaled in the IFR constant value you enter. You didn't specify what brand 42 lb you are using. There seems to be a constant debate whether the SVO green top 42s are rated at 40 or 43.5. I always use 43.5 with them and it seems to work OK.