Results from 180 thermostat :) :)
#11
This brings up a question. INTENSE claims they raise the rpm shift points roughtly 200rpm for the standard PCM upgrade (which is made for stock cams). My question is, is there more of a powerband beyond the stock 6000rpm with the stock cam? If so, how much of a benefit is a couple hundred extra rpm with a stcok cam?
#12
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From: Bloomington-Normal, IL 1997 SE
if you had rockers it would make a difference.
I was the one who asked about KR and power, i was just curious, and I am sure it helped somebody out.
If the tstat thing confuses you try to think about it like this. The stock 195 one will start to open at a higher temp, and will be fully open at around 210-220 if I remember correctly. The 180 will open up sooner and will be fully open at about 200, if you run your car hard and watch the temp gauge with a stock you will see that it will climb up to a certain point and then start to come back down. This is when the tstat is fully open and the maximum amount of coolant is going to your engine. With the 180 this will happen sooner. When you are on the highway and you have the CC on, the engine is making a constant amount of heat because its pretty much running at a constant RPM. Since the 180 opens at a lower temperature it will be open farther when you are cruising at that RPM.
Did I get the jist of it?
I was the one who asked about KR and power, i was just curious, and I am sure it helped somebody out.
If the tstat thing confuses you try to think about it like this. The stock 195 one will start to open at a higher temp, and will be fully open at around 210-220 if I remember correctly. The 180 will open up sooner and will be fully open at about 200, if you run your car hard and watch the temp gauge with a stock you will see that it will climb up to a certain point and then start to come back down. This is when the tstat is fully open and the maximum amount of coolant is going to your engine. With the 180 this will happen sooner. When you are on the highway and you have the CC on, the engine is making a constant amount of heat because its pretty much running at a constant RPM. Since the 180 opens at a lower temperature it will be open farther when you are cruising at that RPM.
Did I get the jist of it?
#13
This brings up a question. INTENSE claims they raise the rpm shift points roughtly 200rpm for the standard PCM upgrade (which is made for stock cams). My question is, is there more of a powerband beyond the stock 6000rpm with the stock cam? If so, how much of a benefit is a couple hundred extra rpm with a stcok cam?
I'd like to be in the 13'* on the stock pcm if I could. Yes too much timing starts diminishing returns and eventually you lose power. past 20 is going to start putting some serious stress on the motor.
#14
Originally Posted by Allmachtige
This brings up a question. INTENSE claims they raise the rpm shift points roughtly 200rpm for the standard PCM upgrade (which is made for stock cams). My question is, is there more of a powerband beyond the stock 6000rpm with the stock cam? If so, how much of a benefit is a couple hundred extra rpm with a stcok cam?
Anyways, if their PCMs shift at 6200 I believe with stock cam and stock rockers that you won't be doing much. Now it might actually help a little (espeically in the 2000+ where the 1-2 shift is at 5400 rpm and the 2-3 is 5500), but not much. I am not sure about the stock power curve, but IIRC it starts falling off at like 5500 or so. I know with rockers the powerband will go until right around 6000 then fall off, however you don't want to shift right at your power peak, thats a waste, you want to go a few hundred rpm after your power peak so the engine is at high enough rpms in the next gear. For instance, the power curve in my dads GTP is pretty flat until about 6000 then it drops off a little. His car shifts at 6200rpm with his current setup...this helps because the car is in the powerband when it shifts into the next gear, and doesn't rev too much where it isn't making power and it doesn't damage things.
I think that personally with the stock cam & rockers that I would shift at 5900-6000 somewhere...with rockers I would pull that out to 6200.
With my car I found that the powerband peaks at 5200rpm and drops off pretty quickly after that. If I leave the car in gear it will shift fron 2-3 at ~5800rpm (this is with a stock tranny setup)...and mind you the redline on the engine is 5500rpm, but stock they shift at 5800, thats GM for you. So anyways, I found that even though the powerband drops off well before when it shifts, that if I hold the car in 2nd gear until about 6100 I gain about 2 tenths and 1mph in the 1/4 mile...and if you look at the power curve you would NEVER think that would be the case, but I guess it just puts the car in the right spot in the next gear, you can definately FEEL that the car isn't making any power revving out that much, but it helps the times so I do it. Also one funny thing about my car that doesn't have anything to do with this but i thought i would add it is, the stock redline is 5500, the stock rev limiter is 6212rpm (doesn't make sense for the limiter to be 712rpm over the redline, but once again, thats GM) and the car shifts from 1-2 usually at around 6000 or so, but every once in a while it will creep up to over 6k and occasionally it will hit the rev limiter before the 1-2 shift, and then it shifts from 2-3 at about 5800 or so...yet the redline is 5500rpms. It won't shift into 4th under WOT (or at least I don't think it will) but I have wound it out to 5900rpm in 3rd without it trying to stop me...honestly I wish it would stop me, I don't need to rev it that high, although I have been told that with proper valvetrain components it will run 7500rpm all day long. I just don't understand why GM does what they do. A stock SSEi with a 6k rpm redline shifts at 5400rpm...but a stock GP with a 5500rpm redline shifts at 6000+rpm, I'll never understand GM.
#15
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From: Bloomington-Normal, IL 1997 SE
there is a delay between the engine and the pavement, thats why you are supposed to shift after the engine goes past its peak power. There was a link to an article that explained it all, but if we cant find it you will have to take my word for it.
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