billy mild

My car is stock except for Borla mufflers and center resonator delete.

The car put down 330 who and 315 ft/lbs of torque. I was going for 350 whp. I have a 91 which is the 375 HP model.

Do these numbers sound about right for a 1991 LT5?

People at the dyno were impressed because they were expecting LT1 numbers.

pushrod-v8

Looks good. My '92 put down 342 rwhp. I forget the torque and this was all stock.

I want to get back on the dyno to see what the car does after modifying the car.

Hopefully that will happen this week.

mike100

my 91 put down 350 rwhp and 330 TQ with a 3" catback, chip, and my own plenum porting job. Once i did the long tube headers- it completely woke the hell up as the previous mods where being held back by the terrible 90-92 manifolds. I would guess it has 380-390 whp now. I also reported the intake a little wider too, but saving the headers for last really added as a package deal and it feels like 30 hp more.

WydGlydJim

I seem to remember 335/335 for my stock '90..it had Flowmaster exhaust

Dominic Sorresso

375 crank would give you ~ 325 wheel horse. So nothing wrong w your numbers. When you modify motors, you begin to understand what it takes to gain 10-20 hp. It's just not that easy. And it isn't simply a matter of hanging a new exhaust on. Changes to the breathing of a motor requires tuning in order to maximize results. You can go to the dyno and pick up 10-15whp w a change to timing and/or fuel.

ghlkal

As others have said, yes those are good numbers for a nearly stock LT5.

BTW, did your dyno operator rev it up to where the LT5 belongs? The first time I took it to the dyno, the operator kept letting off at 5800 ...

billy mild

He let off at 7000 rpm.

FASTAZU

My 91 completely stock 12k miles on it did 324/326 back in 02 when I got it. In 07 with flowmaster catback and Marc's chip 339/346.

billy mild

The car did run rich up top in the rev range. It was in the 11:1 range. I thought that was leaving some power on the table.

I don't want to get a chip just yet as I would like to put longtubes on the car eventually.

Is it hard to tune the LT5?

RICHARD TILL

To tune is just a phone call away. Marc Halibeck 630-458-8427. I recently tied my secondaries open and got a chip from Marc. The performance is great. I just wish it would return to idle speed before the wheels stopped rolling.

Paul Workman

This was my "stock" 1990 Dynojet run, taken one year after I bought it. It was a "base case" run prior to the top end porting planned for that winter.

Note: It was stock except for a Borla cat-back, FYI. Dyno operator cut it off at 6000 rpm, for reasons unknown.

cv67

Sounds about right, know that dynos can read differently so take it with a grain of salt, enjoy the car