Advantages/Disadvantages over 2.6???
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Joined: 10-06-05
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From: Seneca, South Carolina
2.7 pulley will put you at the m62's max 16000 rpms at roughly 6875 engine rpms. after that, you are overspinning the blower and making tons and tons of heat.
2.6 pulley will put you at the m62's max 16000 rpms at roughly 6600 engine rpms. after that, same scenario, overspinning and tons of heat.
So the downfalls, is that you have to shift sooner because of the heat and power loss at high rpms, but you don't want to shift sooner because of the rediculously long gearing in our cars. You'd much rather shift higher and use your gearing better, if you shift sooner, you will fall out of the power band when you hit the next gear.
2.6 pulley will put you at the m62's max 16000 rpms at roughly 6600 engine rpms. after that, same scenario, overspinning and tons of heat.
So the downfalls, is that you have to shift sooner because of the heat and power loss at high rpms, but you don't want to shift sooner because of the rediculously long gearing in our cars. You'd much rather shift higher and use your gearing better, if you shift sooner, you will fall out of the power band when you hit the next gear.
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Joined: 10-11-06
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From: Easton, PA
2.7 pulley will put you at the m62's max 16000 rpms at roughly 6875 engine rpms. after that, you are overspinning the blower and making tons and tons of heat.
2.6 pulley will put you at the m62's max 16000 rpms at roughly 6600 engine rpms. after that, same scenario, overspinning and tons of heat.
So the downfalls, is that you have to shift sooner because of the heat and power loss at high rpms, but you don't want to shift sooner because of the rediculously long gearing in our cars. You'd much rather shift higher and use your gearing better, if you shift sooner, you will fall out of the power band when you hit the next gear.
2.6 pulley will put you at the m62's max 16000 rpms at roughly 6600 engine rpms. after that, same scenario, overspinning and tons of heat.
So the downfalls, is that you have to shift sooner because of the heat and power loss at high rpms, but you don't want to shift sooner because of the rediculously long gearing in our cars. You'd much rather shift higher and use your gearing better, if you shift sooner, you will fall out of the power band when you hit the next gear.
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From: Easton, PA
Meth 40/60 mix and not sure yet getting it dynoed soon but I raced a bmw m3 the one with 330hp and he had a intake and catback and we raced he beat me but I was at his door the whole time so I got to be dam close to 300 or at or over
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From: Boynton Beach, Fl
All worng m62 is max mean overspin is @27psi at 16,000rpms. Ask eaton that's the max not a2.6pully that 20psi and yes u still make a lot of heat but not overspining I'm running a 2.6 with 32 of timmong with meth and my iat2 say at 82 and I don't have a dual bybass plate just meth
Dude. Stop talking.
Id stay with the 2.7
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Joined: 10-06-05
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From: Seneca, South Carolina
I shift at 7500rpms and I'm running a 2.9" pulley. blacksssc06, you are wrong. lol. You shouldn't be making 27psi and eaton doesn't rate this supercharger at a max of 27psi. They rate it at a max continuous rpm of 14,000rpms and a max instant rpm of 16,000rpms. I just know the formula for figuring out what each pulley will "roughly" put the supercharger at per the engines rpm speed.
blacksssc06, what are your track times on your setup?
blacksssc06, what are your track times on your setup?
Last edited by ralliartist; Jan 5, 2009 at 12:25 PM. Reason: Automerged Doublepost
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Joined: 10-01-08
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From: Philthydelphia, PA
wow i feel like a bitch with a 3.1 lol right now i'm trying to get a 2.9 or 3.0 but nobody is willing to trade arggg. i'd stay witha 2.7 or 2.8. is this car Track Only? if so, go get the 2.6 and have at it
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Joined: 10-11-06
Posts: 531
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From: Easton, PA
I shift at 7500rpms and I'm running a 2.9" pulley. blacksssc06, you are wrong. lol. You shouldn't be making 27psi and eaton doesn't rate this supercharger at a max of 27psi. They rate it at a max continuous rpm of 14,000rpms and a max instant rpm of 16,000rpms. I just know the formula for figuring out what each pulley will "roughly" put the supercharger at per the engines rpm speed.
blacksssc06, what are your track times on your setup?
blacksssc06, what are your track times on your setup?
I shift at 7500rpms and I'm running a 2.9" pulley. blacksssc06, you are wrong. lol. You shouldn't be making 27psi and eaton doesn't rate this supercharger at a max of 27psi. They rate it at a max continuous rpm of 14,000rpms and a max instant rpm of 16,000rpms. I just know the formula for figuring out what each pulley will "roughly" put the supercharger at per the engines rpm speed.
blacksssc06, what are your track times on your setup?
blacksssc06, what are your track times on your setup?
Last edited by blacksssc06; Jan 5, 2009 at 01:07 PM. Reason: Automerged Doublepost
Senior Member
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From: Boynton Beach, Fl
For people who either dont care, or people who are unaware of actual mathematical facts that prove danger.
And were not saying it wouldnt work, but it WIL cause problems in the future.
And were not saying it wouldnt work, but it WIL cause problems in the future.
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From: Easton, PA
The M62 cannot be destroyed or damaged by over spinning it. That part of the debate can end because it's not an issue.
The real issue is in the application of this blower on this car. Pulleys smaller than a 3.0 are not going to produce additional gains on the 2.0 unless you have more displacement, cams, or a ported head. The boost levels just get too high to benefit. As boost levels climb the power required to spin the blower rises and therefore gains diminish.
As boost levels climb, so does heat and cylinder pressure from additional air. This reduces the timing you can run which lowers HP. This is why you can hit 260WHP with a 3.1" pulley. If you look at any hpt file, you'll notice timing drops as airflow increases. This is true for a stock file, stage 2 file, etc. As timing drops from KR or from the table, HP will as well. Running a 2.8" over a 3.0 pulley can change the timing table by 2 deg (and more if you have KR). This will drop you approx 10HP by 7k rpm.
Additionally, a larger pulley allows you to run leaner which makes power on these engines. Larger pulleys are safer.
Nearly this entire community has a great misconception on small pulleys making more HP and I'm not sure why people aren't looking at the data. Add race gas or pure alcohol and the optimum pulley size may be smaller but for now forget about the 2.x pulleys and enjoy the 250+ WHP that's so easy to be had safely with 3.x" pulleys.
The real issue is in the application of this blower on this car. Pulleys smaller than a 3.0 are not going to produce additional gains on the 2.0 unless you have more displacement, cams, or a ported head. The boost levels just get too high to benefit. As boost levels climb the power required to spin the blower rises and therefore gains diminish.
As boost levels climb, so does heat and cylinder pressure from additional air. This reduces the timing you can run which lowers HP. This is why you can hit 260WHP with a 3.1" pulley. If you look at any hpt file, you'll notice timing drops as airflow increases. This is true for a stock file, stage 2 file, etc. As timing drops from KR or from the table, HP will as well. Running a 2.8" over a 3.0 pulley can change the timing table by 2 deg (and more if you have KR). This will drop you approx 10HP by 7k rpm.
Additionally, a larger pulley allows you to run leaner which makes power on these engines. Larger pulleys are safer.
Nearly this entire community has a great misconception on small pulleys making more HP and I'm not sure why people aren't looking at the data. Add race gas or pure alcohol and the optimum pulley size may be smaller but for now forget about the 2.x pulleys and enjoy the 250+ WHP that's so easy to be had safely with 3.x" pulleys.
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Joined: 07-16-08
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From: Boynton Beach, Fl
Although it is very unlikely, im pretty sure it is possible to destroy anything 
... but at a certain point, over spinning could cause seizure by over heating its internals.
How is your tuning going to be done? Either way, zoomer is right about making safer power on the 2.7 than the 2.6. Although if you were hardcore tuning and didnt care, the 2.6 would yield more power, but i dont think your going that route.
... but at a certain point, over spinning could cause seizure by over heating its internals.How is your tuning going to be done? Either way, zoomer is right about making safer power on the 2.7 than the 2.6. Although if you were hardcore tuning and didnt care, the 2.6 would yield more power, but i dont think your going that route.
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From: Pittsburgh, PA
To think, I ran 10:1 pistons, 2.5" ring on the blower w/ meth. Stock everything else. Car ran like a raped ape.
Why is it that the only people to crack 300whp without another power adder, are the ones with 2.5/2.6 rings... and no one else has done it yet?
If I got another one of these cars, I would put a 2.5" ring on it again without a second thought. It dropped the TQ curve so low, car was a blast to drive.
Why is it that the only people to crack 300whp without another power adder, are the ones with 2.5/2.6 rings... and no one else has done it yet?
If I got another one of these cars, I would put a 2.5" ring on it again without a second thought. It dropped the TQ curve so low, car was a blast to drive.
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From: Still fixing others mistakes.
To think, I ran 10:1 pistons, 2.5" ring on the blower w/ meth. Stock everything else. Car ran like a raped ape.
Why is it that the only people to crack 300whp without another power adder, are the ones with 2.5/2.6 rings... and no one else has done it yet?
If I got another one of these cars, I would put a 2.5" ring on it again without a second thought. It dropped the TQ curve so low, car was a blast to drive.
Why is it that the only people to crack 300whp without another power adder, are the ones with 2.5/2.6 rings... and no one else has done it yet?
If I got another one of these cars, I would put a 2.5" ring on it again without a second thought. It dropped the TQ curve so low, car was a blast to drive.
Although it is very unlikely, im pretty sure it is possible to destroy anything ... but at a certain point, over spinning could cause seizure by over heating its internals.
How is your tuning going to be done? Either way, zoomer is right about making safer power on the 2.7 than the 2.6. Although if you were hardcore tuning and didnt care, the 2.6 would yield more power, but i dont think your going that route.
... but at a certain point, over spinning could cause seizure by over heating its internals.How is your tuning going to be done? Either way, zoomer is right about making safer power on the 2.7 than the 2.6. Although if you were hardcore tuning and didnt care, the 2.6 would yield more power, but i dont think your going that route.
and no, he won't make more power with the 2.6. He'll make less. If he wants to go faster he should run a LARGER pulley than the current 2.7
We've shown people this many times on our dyno when they came in for tuning. Always the same thing..."how small of a pulley can I run" and then we show them on the dyno and they leave with a 3.0 or 3.1
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From: Pittsburgh, PA
