Robbed

**N20LT4** · 08-02-2007, 12:48 PM

I just had to ask -- to see if it was just my car, or what, but it seems like the heat robs LT1's more than any other motor. I mean, I owned an '98 LS1, and that car even in the middle of the summer, did not let the heat get to it. I mean of course it was it's fastest in cool weather, but it just seems like with the LT motors 95-degree heat can rob of you of 30 to 40 horsepower easily, atleast that's what it feels like. Is it the opti-spark that's very prone to heat, and maybe that's what takes the power away momentarily? I'm serious guys, my car will melt the tires viciously at night (off the bottle) with no problem, and then when it's 90 -deg or above it's like it doesn't even want to spin. I just want to know if someone can tell me exactly what makes this problem stand out so much on LT1's??

**ice97ta** · 08-02-2007, 01:50 PM

dang 30-40hp, not that much maybe like 3-5 but nothing to noticable.

**5.0THIS** · 08-02-2007, 02:16 PM

After tuning my PCM, I was seeing less than 10hp loss between 170-200 degrees. Mine rarely gets above 185~ anyway

**Red4Mula** · 08-02-2007, 06:10 PM

Originally Posted by N20LT4

I just had to ask -- to see if it was just my car, or what, but it seems like the heat robs LT1's more than any other motor. I mean, I owned an '98 LS1, and that car even in the middle of the summer, did not let the heat get to it. I mean of course it was it's fastest in cool weather, but it just seems like with the LT motors 95-degree heat can rob of you of 30 to 40 horsepower easily, atleast that's what it feels like. Is it the opti-spark that's very prone to heat, and maybe that's what takes the power away momentarily? I'm serious guys, my car will melt the tires viciously at night (off the bottle) with no problem, and then when it's 90 -deg or above it's like it doesn't even want to spin. I just want to know if someone can tell me exactly what makes this problem stand out so much on LT1's??

Same here

**xinthenight** · 08-05-2007, 08:06 AM

I don't notice THAT much of a difference with my LT1 in even 100-105 degree weather. Maybe you're just so frustrated that it makex you feel like it's even more.

I am, however, working on a custom fiberglass hood for my Lt1 and planning that will be an exact replca of the current hood but I'm going to actually cut out the 2 vents hoping it will help some. Just gotta read more in my autobody book on how to get it bolted in good enough so that it doesn't rattle at high speeds.

Is there any paint that I could use that would block some heat? I'll have to search for that later today when I get back home.

**N20LT4** · 08-05-2007, 08:54 AM

Originally Posted by xinthenight

I don't notice THAT much of a difference with my LT1 in even 100-105 degree weather. Maybe you're just so frustrated that it makex you feel like it's even more.

I am, however, working on a custom fiberglass hood for my Lt1 and planning that will be an exact replca of the current hood but I'm going to actually cut out the 2 vents hoping it will help some. Just gotta read more in my autobody book on how to get it bolted in good enough so that it doesn't rattle at high speeds.

Is there any paint that I could use that would block some heat? I'll have to search for that later today when I get back home.

Trust me, it's not frustration

. None of my other cars suffered from heat as bad as this one. It could be a number of things, who knows???

**Chad97z** · 08-09-2007, 04:25 AM

Fortunately, my car does not do that. It's strong 24x7. But I would check any electronic device that checks for air temperature or humidity or even a map sensor. Sometimes the computer may not see a faulty sensor but the sensor will still give false information. I'd check resistance values or replace sensors related to climate conditions. It would be interesting to monitor your timing when you think the engine is not running at optimum. It strongly doubt it's an optispark, that would cause a misfire. You have an over all tuning problem and it's not going to be a bad wire or something like that or "mechainical". I would check anything that effects the timing of your car. And a computer takes various real time measurements to adjust the timing on the fly. You'd have to do some research on that. Its too early for me. =)

**kevinboy** · 08-09-2007, 09:26 AM

man i live in stockbridge GA and it is like in the 100's i got a 94 z mine is doing the same shit i dont have a solution yet but i am just lettin you noe ure not the only one

**JodyJ** · 08-10-2007, 11:13 AM

Do you have a data logger? Maybe the car is retarding the timing because of the heat and other stuff. Log your car during the heat and see what happens.

Jody J.

**N20LT4** · 08-10-2007, 05:30 PM

Originally Posted by Chad97z

Fortunately, my car does not do that. It's strong 24x7. But I would check any electronic device that checks for air temperature or humidity or even a map sensor. Sometimes the computer may not see a faulty sensor but the sensor will still give false information. I'd check resistance values or replace sensors related to climate conditions. It would be interesting to monitor your timing when you think the engine is not running at optimum. It strongly doubt it's an optispark, that would cause a misfire. You have an over all tuning problem and it's not going to be a bad wire or something like that or "mechainical". I would check anything that effects the timing of your car. And a computer takes various real time measurements to adjust the timing on the fly. You'd have to do some research on that. Its too early for me. =)

Well that's the thing, it does have a mis. The old opti was stressing under heat. MAP sensor checked O.K. I received my Accel Opti 2 from Summit Racing Tuesday and will be installing it tommorrow. That should solve the problem!