88 chevy 1500 tuning issues

[CDeeZ]

I think you could crank out 500 HP using a stock TBI system. Would have to step up to a larger throttle body but I think everything else could definitely do it. Unless you just want to switch to an aftermarket setup.

[Fast355]

I think you could crank out 500 HP using a stock TBI system. Would have to step up to a larger throttle body but I think everything else could definitely do it. Unless you just want to switch to an aftermarket setup.

With a single 2.00" bore 420 hp 496 TBI unit using the high pressure 61s at 32 psi for 105 lb/hr I ran out of engine before I came close to running out of air or fuel. 370 rwhp through a 4L60E, GM 12 bolt and 2 piece driveline with carrier bearing. Was making atleast 450 hp.

[CDeeZ]

With a single 2.00" bore 420 hp 496 TBI unit using the high pressure 61s at 32 psi for 105 lb/hr I ran out of engine before I came close to running out of air or fuel. 370 rwhp through a 4L60E, GM 12 bolt and 2 piece driveline with carrier bearing. Was making atleast 450 hp.

Makes me wonder exactly how the general consensus (wrong as it is!) started among the crowd that "TBI is junk" "It can't make power" ..... Well you know how all that goes....... All the sidline shit talkers that said it couldn't be done.......

[Aceman]

Did you raise the rev limiter ? mine was set a 4800 stock. I would hit it hard with a thm 350 in kickdown at shiftpoints instead of the4l60e. raised it to 6000. no problem

[woody80z28]

Extremely similar build to my truck. I like it.

[Fast355]

Extremely similar build to my truck. I like it.

Very similar to what I am currently building for a 5.7 Vortec application as well.

The engine I am building has stock 906 heads with Comp 787 retainers, .050" offset locks and GMPP Blue LS6 springs. Pushrod holes drilled out to 1/2".

I had Comp Cams custom grind a roller cam. Using the older and milder Magnum lobes.

270/284 @ .006
215/223 @ .050
.533/.533 w 1.6 rocker
110 LSA +4* advance

Will be running it under a stock vortec intake setup that has a ported lower intake and MFI conversion spider at 70 psi. 1 5/8" primary long tube headers with 2.5" collectors, dual 2.5" exhaust to the magnaflow di/so muffler with high flow cats and a single 3.5" tail pipe.

The cam should sound alot like a GM Hotcam but start making power about 3-400 rpm sooner. Peak torque should happen in the 3,500 rpm range and peak HP in the 5,500 rpm range. Just a guess but the rpm effective range should be 1,500-5,500 rpm which should work very well with the factory 4.3 torque converter and 3.73 gears.

For reference the GM Hotcam
278/287 @ .006
218/228 @ .050
.525/.525 w 1.6 rocker
112 LSA +3* advanced
Advertised as 1,800-5,800 rpm.

[CDeeZ]

Extremely similar build to my truck. I like it.

You mentioned that your fuel pressure is 20 PSI.... What did you have to do in the tune to do in the tune to make it happy down low at idle? I'm thinking transient paramters are what need adjusted but haven't been able to look around yet.

[woody80z28]

I just changed the injector flow rate at 0x4D88 to 80lbhr and then tuned the idle fuel via VE