it was.

Well if it had those mods it very well should have made peak power at a much higher RPM. People with the small TR224/224 .580/.588 112LSA cam are making people power at 6200RPM with stock heads. The Magic stick cam is around 6800 with aftermarket heads.

If the forced induction type was the right CFM output it should have raised the peak power number. Just because I say the peak HP should have been at a higher RPM doesn't mean it sacrfices low end very much if at all. It doesn't matter at all how you look at it, if you start the dyno pull at 2K regardless of what cam you have there's gonna be monstrous torque numbers because of course a 2.6 puts out enough CFM for 2K rpm.

I've raced grand nationals that trap from 113 to 115 from a roll and put a car on them instantly even giving them a hit and they couldn't pull back. If I didn't have a positive displacement type blower then that wouldn't have happened. It's still an M90 over a T67 though. What happens whenever they build boost and race from a stop is a different story though.:eek:
 
CMac89 said:
Well if it had those mods it very well should have made peak power at a much higher RPM. People with the small TR224/224 .580/.588 112LSA cam are making people power at 6200RPM with stock heads. The Magic stick cam is around 6800 with aftermarket heads.

If the forced induction type was the right CFM output it should have raised the peak power number. Just because I say the peak HP should have been at a higher RPM doesn't mean it sacrfices low end very much if at all. It doesn't matter at all how you look at it, if you start the dyno pull at 2K regardless of what cam you have there's gonna be monstrous torque numbers because of course a 2.6 puts out enough CFM for 2K rpm.

I've raced grand nationals that trap from 113 to 115 from a roll and put a car on them instantly even giving them a hit and they couldn't pull back. If I didn't have a positive displacement type blower then that wouldn't have happened. It's still an M90 over a T67 though. What happens whenever they build boost and race from a stop is a different story though.:eek:
So then if the problem is a lack of CFM capability, then I would expect that one would be observing a drop-off of boost at high rpm also, no?
 
No, I believe that cam timing is of minor consequence in this case. I'd like to see any dyno chart of a positive displacement street motor making peak power at or above the rpm at which it would have made peak hp were it NA. And I would like to see it run with an IC and at least 12psi boost.

Anyone?
 
http://videos.streetfire.net/video/cc7646e8-6e20-4eac-aef2-9821017f9133.htm



http://video.ls1tech.com/video/95055418-f79b-47a8-9f85-982100b666f2.htm

my friends fox mustang pulling tire on the street. and some procharged ls1 action!

--------------------------------------------------------------------------------

this is a video of some of our local grudge matches.

the first race is the fox mustang vs a procharged ls1 ta with headers exhaust built trans 4.10s and a tune. both running slicks.


second race is a built 355 lt1 ta with spray vs a 421 CI small block truck that i cant even begin to describe the mods to.


third race is a mild 302 fox with spray against my buddies fox. this is the race the black fox pulls tire. its my friend nicks.

lets hear some feedback. and enjoy!
 
XR7 Dave said:
No, I believe that cam timing is of minor consequence in this case. I'd like to see any dyno chart of a positive displacement street motor making peak power at or above the rpm at which it would have made peak hp were it NA. And I would like to see it run with an IC and at least 12psi boost.

Anyone?

I've got one with the HP peak right at redline, and that's higher than it was N/A. But it's far below the 12 PSI requirement.
 
Andy 94SC said:
I've got one with the HP peak right at redline, and that's higher than it was N/A. But it's far below the 12 PSI requirement.

My point exactly.

I don't think you'll find a street motor with high boost and an IC that will make a power curve like yours. The reason (as far as I can see) is that the IC is extremely efficient at low rpm creating an artificially high torque peak. This advantage falls away as ACT's climb with rpm and the flow restriction of the IC starts to come into play. The end result is that the torque falls off at higher rpm. If the same motor were run without the IC (and sufficient fuel to make that possible) you would see a power curve that looks more like yours.

There is no question in my mind that going without an IC is way more efficient at making power. Controlling the heat that results is a different story altogether.
 
oldschoolmuscle said:
third race is a mild 302 fox with spray against my buddies fox. this is the race the black fox pulls tire. its my friend nicks.

lets hear some feedback. and enjoy!

would be a good race against my buddys stang..

heres his car pickin the tire up in the street also

http://www.yousendit.com/transfer.php?action=download&ufid=855CA3FA12C577B2

same car, same street... from the back, was quite interesting. I was standing where you see him drift off into the grass a bit. Still pulled off the win and put some $$$ in my pocket as well :D

http://www.yousendit.com/transfer.php?action=download&ufid=64C1FE4A7D3CB22E
 
Last edited:
how did i miss this thread..

what is wrong with MR LS1 ? (old school)

i might be buying a 98 Z28 this week..

but i still love my SC.


too bad i missed all of the 1fastsc stuff..

I just wish people would actually use their evos for WRC, instead of talking about how AWD is king of c o c k s, i mean 60' foot ;)

i guess he never considered SC guys dont care about being the fastest.. and really enjoy just driving our cars

speed is fun.. but if you have to do it in a yellow toolbox looking thing.. no thanks

not my cup of tea..

am i allowed to say that here ? wait i think i can because this is the SCCOA.. im not an SC owner trolling on an EVO board.. thats right.
 
God I love it when you post, you've made my day.


Have fun with the Camaro =)

Thunder427 said:
how did i miss this thread..

what is wrong with MR LS1 ? (old school)

i might be buying a 98 Z28 this week..

but i still love my SC.


too bad i missed all of the 1fastsc stuff..

I just wish people would actually use their evos for WRC, instead of talking about how AWD is king of c o c k s, i mean 60' foot ;)

i guess he never considered SC guys dont care about being the fastest.. and really enjoy just driving our cars

speed is fun.. but if you have to do it in a yellow toolbox looking thing.. no thanks

not my cup of tea..

am i allowed to say that here ? wait i think i can because this is the SCCOA.. im not an SC owner trolling on an EVO board.. thats right.
 
XR7 Dave said:
My point exactly.

I don't think you'll find a street motor with high boost and an IC that will make a power curve like yours. The reason (as far as I can see) is that the IC is extremely efficient at low rpm creating an artificially high torque peak. This advantage falls away as ACT's climb with rpm and the flow restriction of the IC starts to come into play. The end result is that the torque falls off at higher rpm. If the same motor were run without the IC (and sufficient fuel to make that possible) you would see a power curve that looks more like yours.

There is no question in my mind that going without an IC is way more efficient at making power. Controlling the heat that results is a different story altogether.

Myself, I am a big fan of charge air coolers. I was doing some more digging. The closest I could come up with is a guy at "11 - 11.5 PSI" on a setup very similar to mine. However I can't find a dyno sheet of his current setup. The one I have is from when he was running 10 PSI.
locked.jpg


The HP peak is still up there in RPM. But I am suprised at the low numbers...:confused:

Anyway, I am not so sure the HP dropoff would be due to the flow restriction of the I/C so much as it might be the fact that the I/C isn't able to cool the air as well as at lower boost levels / RPM.
 
XR7 Dave said:
My point exactly.

I don't think you'll find a street motor with high boost and an IC that will make a power curve like yours. The reason (as far as I can see) is that the IC is extremely efficient at low rpm creating an artificially high torque peak. This advantage falls away as ACT's climb with rpm and the flow restriction of the IC starts to come into play. The end result is that the torque falls off at higher rpm. If the same motor were run without the IC (and sufficient fuel to make that possible) you would see a power curve that looks more like yours.

There is no question in my mind that going without an IC is way more efficient at making power. Controlling the heat that results is a different story altogether.


I disgree. But I want to ask the question....are we talking about a turbo or a super charged car?

I want to know that answer before I disagree anymore, if it's an SC car then I don't disagree because I know squat about how SC cars and intercoolers work.
 
Andy 94SC said:
Anyway, I am not so sure the HP dropoff would be due to the flow restriction of the I/C so much as it might be the fact that the I/C isn't able to cool the air as well as at lower boost levels / RPM.

I believe you are correct sir. Flow restriction from the IC isn't always the problem but it often is. Also, looking at the intake on that Vette I don't believe that it was big enough to support that kind of HP. I could be wrong though.
 
1FASTSC said:
I disgree. But I want to ask the question....are we talking about a turbo or a super charged car?

I want to know that answer before I disagree anymore, if it's an SC car then I don't disagree because I know squat about how SC cars and intercoolers work.

He did say Positive Displacement. That rules out Turbo's, and Centrifugal Superchargers.
 
The post Charles put up for a lightning (I'm not going through pages and pages of BS to find it) showed a lightning with his blower running low boost and his blower running high boost. The low boost graph was low on torque and the high boost one had monstrous torque but the HP didn't show that kind of an increase. All the graphs I've seen for positive displacement blowers follow this pattern. Even with an M90 on an SC motor if you run low enough boost you can get very impressive top end numbers compared to your lower numbers. On an SC you could say anything you want about flow and restriction and I'd believe it but I see this trend on all the high boost positive displacement motors I've seen. Even the Cobra power band starts to move down significantly when boost is high and that really should be a high revving motor.

I would also like to see how much HP it takes to spin a good twin screw at high rpm and boost. I've logged SC's so I can give you a pretty good idea how much our motors eat up but I can't comment on the "other" guys. Ours are not eating up as much HP as you might think. I do have a MAP of a whipple 2300 that shows power consumption at about 65hp at a 2:1 pressure ratio at moderate rpms. None of the charts go up to the 17K+ that people are taking these things to though so unfortunately I can't comment on that.
 
XR7 Dave said:
So then if the problem is a lack of CFM capability, then I would expect that one would be observing a drop-off of boost at high rpm also, no?
I forgot all about this discussion.

No I don't think it's that bad. RPM is what keeps the boost constant so it won't drop off.

One problem that is worked on by many drag racers that run positive displacement blowers is to find different pulley combinations to keep the boost climbing as the RPM's increase. This gets rid of the low peak HP numbers and fall off of torque.

Don't get me wrong as there is always a base boost number that the motor sees as soon as it goes WOT.
 
I'm not too sure I agree on the whole air charge temperatures being more of a steep factor than CFM is. I would say that they go hand in hand if anything. If you could make an M90's intake temps 60* it would only make so much power because it isn't providing enough CFM to make any more power.

Charles' test isn't so much of the blower's fault as it is the internals of the motor's. Of course the higher boost is going to create a higher torque number because the motor isn't a restriction to the blower at a lower RPM. Once you get to the higher RPM's then it's all about head flow/volumes. You can boost it all you want, but if there isn't enough intake volume then it wont take the boost fast enough in one big pulse.

Air charge temps would be a compensation due to being able to regulate the timing better the cooler it gets.
 
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