well after 5 years my 383 is alive and dyno'd

[87vette81big]

The Injector offset & battery cimpensation tables may be skewed.
Miss programmed.
Nosing over in 3rd gear.

 

[stroker87]

The Injector offset & battery cimpensation tables may be skewed.
Miss programmed.
Nosing over in 3rd gear.

Air fuel when you nail it, it hits 13.1 just for a hair then it 12.5 to 12.8 for the rest of the pull (that where it made the best power)

 

[87vette81big]

Your Combo is not dialed in.
Reprogram. If you can't do it find someone that can...
Or remove Stealth Ram & install a Dual plane or single plane & a Good Holley HP series Race Carb.
Or a professional Race BLP Bo Laws Carb.
Your Headers & exhaust system is far from Race.
More like a toy exhaust system.

 

[87vette81big]

You might want to go through the Mathmatics of Injector fuel flow.
80% Now Duty cycle.

 

[87vette81big]

Its just me but I haven't been impressed with all off the shelf EFI systems & typical upgrades.
Guys have taken stock GM TPI into the 11's.
A single 4-bbl Holley Race carb on single plane into 9's normally aspirated I have known.
Kicker nitrous into the 8's. Still just a 4-Bbl.

 

[stroker87]

You might want to go through the Mathmatics of Injector fuel flow.
80% Now Duty cycle.

the dyno operator told me the injectors was fine I asked if they was maxed out he said no? he had not problems making the truck run a lower WOT A/F ratio but when he did it made less power

I dont know, two engine combo's both having the same problem tell me there is a problem just where is it at in the trans? tune? timing?

 

[87vette81big]

You might want to go through the Mathmatics of Injector fuel flow.
80% Now Duty cycle.

the dyno operator told me the injectors was fine I asked if they was maxed out he said no? he had not problems making the truck run a lower WOT A/F ratio but when he did it made less power

I dont know, two engine combo's both having the same problem tell me there is a problem just where is it at in the trans? tune? timing?

This is why Grumpy preferd a BBC In C4 Corvrttes.
He is shoving over 600 Ft/lbs torque in a Medium range power window.
Just the Dana 36 & Dana 44's keep blowing up along with 700R4 transmissions.

He told you where to check already.
Exhaust back pressure testing.
An accurate Vacuum - Fuel pressure guage will suffice.
What size are the header primary tube diameters? Tube lengths ? Collector length?
Seen no Dyno sheets. No Brake Fuel Consumption numbers.
No intake manifold vacuum readings.
No RPM, Horsepower & Torque charts & graphs.

 

[stroker87]

He told you where to check already.
Exhaust back pressure testing. I'm going to try to test this very soon
What size are the header primary tube diameters? 1 5/8" 3" collectors
Tube lengths ? not sure sorry
Collector length? about 5" to 8"
Seen no Dyno sheets. its not much help theres no torque numbers or A/F but from 3k there right at 300rwhp and it a nice smooth clime to 342rwhp about 5500rpm and holds it till about 6200rmp (where rev limiter it)
No Brake Fuel Consumption numbers. how can i find these out?
No intake manifold vacuum readings. gauge will soon be installed

 

[87vette81big]

What I suspected.
Itsy Bitsy Dinky Headers in place.
Step up to 1-3/4" primary tubes.
1-7/8 & 2 " cost big $$$$.

 

[stroker87]

that would make sense since this is the 2nd combo with the same problem......

 

[87vette81big]

that would make sense since this is the 2nd combo with the same problem......

Its an oversight by nearly all wanting to drag race or road race.
Most off the shelf headers lackluster.
Dont know why they were made right for Race Pontiac V8 engines.
I like Chevy too.