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I took my car to see just what kind of hp I was getting at the wheels. The only mods are a stage 3 hypertech chip, test pipe (no catalytic converter), and monza mufflers (c'mon...this was done in the 80's). The numbers are not what I expected. I was hoping for around 200hp at the wheels seeing as stock this engine was supposed to make about 230hp at the crank. Having never done this before the only takeaway is that my car makes 175hp and 264 torque. Does the air/fuel tell me anything? The car is running real well and I just tuned it up replacing all filters, fluids, plugs, wires, rotor, cap, etc. What are your thoughts?
Last edited by bartenderfloyd; Nov 25, 2020 at 01:31 PM.
230 Horsepower 35 years ago doesn't mean it still makes 230 today.
Its running about a point rich, but the power is about what I'd expect from an 85 L98.
You could probably pick up 10-12 HP with changes to the fueling.
BT Floyd, Northern NJ guy here (I grew up in Blauvelt). Where did you get the dyno done? Do they do dyno tuning? You're one of the 1st guys in my area that has done a dyno (rarer to find a LT1 tuner). Thanks.
230 Horsepower 35 years ago doesn't mean it still makes 230 today.
Its running about a point rich, but the power is about what I'd expect from an 85 L98.
You could probably pick up 10-12 HP with changes to the fueling.
The cars aren't exactly powerful.
my buddy dynoed his stock 84 and those are the numbers it made.... unless its been flogged to death its entire life I'd say something is amiss. Guys report losses in et and MPH with chips. I'd start there imo.
my buddy dynoed his stock 84 and those are the numbers it made.... unless its been flogged to death its entire life I'd say something is amiss. Guys report losses in et and MPH with chips. I'd start there imo.
The chip is absolutely to blame for the fueling. I wonder what its doing to timing as well.
The slightly modded engine peaked earlier than it does in stock form, not later as it should.
That's likely where the missing power has gone.
BT Floyd, Northern NJ guy here (I grew up in Blauvelt). Where did you get the dyno done? Do they do dyno tuning? You're one of the 1st guys in my area that has done a dyno (rarer to find a LT1 tuner). Thanks.
Syngarage 301 Route 17 South Hillburn, NY 10931, right across from the Mt Fuji entrance. Talk to Mike, cost me $125 for 3 pulls.
Last edited by bartenderfloyd; Nov 25, 2020 at 07:19 PM.
my buddy dynoed his stock 84 and those are the numbers it made.... unless its been flogged to death its entire life I'd say something is amiss. Guys report losses in et and MPH with chips. I'd start there imo.
This is what I suspect as well. When I checked the timing it was a bit advanced, 8 degrees before TDC I think. I assumed the chip was doing that. I was thinking about putting on headers and changing out the computer (EFI EBL) but since it runs so well and I have so much fun with it I might just leave it alone.
Agreed with everyone above--Hypertech is trash. There's nothing wrong with chipping the older ECMs, but you have to do it the right way. With an emulator and a dyno, making sane adjustments relevant to the specific setup you have on your car. Then finalize the changes, burn to a chip, and you're off to the races. Unfortunately finding guys who can do things "old school" is getting harder and harder by the year. Lots of places won't touch your car unless they can just plug HPTuners into it.
A bit more info, the car has less than 13,000 miles and was climate controlled garage kept. It has been in my family since new. The 175 hp was at the wheels, not the crank. I know you generally lose 15 to 20 percent power from the crank to the wheels which is why I think something is amiss. I don't have the original chip so like I said above I think the EBL is the way to go.
A bit more info, the car has less than 13,000 miles and was climate controlled garage kept. It has been in my family since new. The 175 hp was at the wheels, not the crank. I know you generally lose 15 to 20 percent power from the crank to the wheels which is why I think something is amiss. I don't have the original chip so like I said above I think the EBL is the way to go.
80% of 230 HP is 184 HP. You're not that far off.
The exhaust should've picked you up some power though, at least raising your peak RPM.
If you think the power it has is fine while driving, I don't see any reason to start making changes.
This is what I suspect as well. When I checked the timing it was a bit advanced, 8 degrees before TDC I think. I assumed the chip was doing that. I was thinking about putting on headers and changing out the computer (EFI EBL) but since it runs so well and I have so much fun with it I might just leave it alone.
8 degrees with the EST wire unplugged or 8 degrees just sticking a timing light on it? I have to ask as people don't always know to unplug that wire.
This is what I suspect as well. When I checked the timing it was a bit advanced, 8 degrees before TDC I think. I assumed the chip was doing that. I was thinking about putting on headers and changing out the computer (EFI EBL) but since it runs so well and I have so much fun with it I might just leave it alone.
6 BTD is stock, 8 is where you should have set it, base timing. Chip sets the advance, not the base.
A bit more info, the car has less than 13,000 miles and was climate controlled garage kept. It has been in my family since new. The 175 hp was at the wheels, not the crank. I know you generally lose 15 to 20 percent power from the crank to the wheels which is why I think something is amiss. I don't have the original chip so like I said above I think the EBL is the way to go.
13,000 miles in 30+ years?
Not enough time or miles for the cam lobes to wear down or anything major with the internals.
The earlier cars (85 and 86) target 12.0 AFR at WOT with no rpm influence, so the fueling is on the money relative to the target and design. The later 87-88 and 89 cars do have leaner targets which approach 12.8:1 as rpm increases, but this was not the case for 85 and 86. The Hypertech chip is not to blame.
The 8 degree initial advance setting will add 2 degrees globally and the Hypertech chip will likely add a bit more advance relative to stock. There is a good possibility that you have too much timing since the effect is additive. I'd go back to 6 degrees initial advance.
Last edited by tequilaboy; Nov 26, 2020 at 04:08 AM.
I drank the Hypertech Coolaid back in the early 90's, there wasn't many choices back then.
I have the Hypertech Bin, and they really did very little.
Very small changes to the spark tables, they lowered the fan temp, and leaned out the fuel.
Some torque converter lockup changes also.
Not much else I could see....
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Looks like a fuel issue to me. About 11.5 at tip in and goes to 12.5ish and bobbles around all the way out UNTIL you get to 5K and it is leaning out and is overall gradually leaning out anyway. Check you fuel pressure and VE table if you can. I shoot for 12.6 - 13.1 and feed the motor what it wants for fuel for best power. If 12.8 works, than go with it. Never have been a fan of a "CANNED" tune chip, every motor is different.
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