From a Heartbeat 93mm to a 90mm pulley - Worth maybe 20 RWHP ?
06-16-2019, 10:15 AM
#1
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2021 C6 of the Year Finalist - Modified
From a Heartbeat 93mm to a 90mm pulley - Worth maybe 20 RWHP ?
I am currently using a 93mm drive pulley on my Heartbeat SC that is installed on my 2011 GS with A6 transmission.
Other than the Heartbeat SC, a set of 1 3/4" headers, a BAP and a dyno tune, this car is bone stock (stock heads and cam)
Just wondering if going from a 93mm to a 90mm pulley might be worth an additional 20 RWHP on the dyno.
The car makes 535 RWHP @ 6,300 now.
What do ya think? .... 555 RWHP with the 90mm pulley ?
Thanks ... Ron
.
Other than the Heartbeat SC, a set of 1 3/4" headers, a BAP and a dyno tune, this car is bone stock (stock heads and cam)
Just wondering if going from a 93mm to a 90mm pulley might be worth an additional 20 RWHP on the dyno.
The car makes 535 RWHP @ 6,300 now.
What do ya think? .... 555 RWHP with the 90mm pulley ?
Thanks ... Ron
.
Last edited by Turbo6TA; 06-16-2019 at 10:21 AM.
06-16-2019, 11:57 AM
#2
That would be a pretty good estimate, I think. My car was plenty of fun with that combination. Made 8.5psi (at sea level) and never showed a trace of KR on 93 octane pump gas. I recall that the IDC was around 93% or so, with the standard issue ZR-1 injectors, so the 90mm pulley is probably going to be just about at the limit for your injectors.
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Turbo6TA (06-16-2019)
06-16-2019, 12:17 PM
#3
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Thank you sir !
06-16-2019, 01:01 PM
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I am thinking that going from a 93mm pulley to a 90mm pulley will require a shorter belt.
I used the same belt that came with the Heartbeat and it's 96mm standard pulley when I switched to the smaller 93mm pulley ... Gates K060980 (98.07" Length)
With the 90mm pulley, the next smaller belt is the ... Gates K060975 (97.54" Length)
I guess that's the belt I would need for the 90mm pulley (since I am using a stock diameter 'PowerBond' Race Performance harmonic balancer).
I used the same belt that came with the Heartbeat and it's 96mm standard pulley when I switched to the smaller 93mm pulley ... Gates K060980 (98.07" Length)
With the 90mm pulley, the next smaller belt is the ... Gates K060975 (97.54" Length)
I guess that's the belt I would need for the 90mm pulley (since I am using a stock diameter 'PowerBond' Race Performance harmonic balancer).
06-17-2019, 02:10 PM
#5
Le Mans Master
Sammy is spot on with the HP estimate. With the belt you have now, if you can easily get it on and off....it's too long. The more load you put on the belt, the more it's going to stretch. And the faster you turn the blower, the more load you have. When you let the tensioner go after installing the belt, it shouldn't move much. If it does, again, you need a shorter belt. The way you're configured, you shouldn't need much other that a stock type belt. Grab a few in the size range you think you'll need. Take back the ones that don't fit.
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Turbo6TA (06-17-2019)
06-17-2019, 05:45 PM
#6
Sammy is spot on with the HP estimate. With the belt you have now, if you can easily get it on and off....it's too long. The more load you put on the belt, the more it's going to stretch. And the faster you turn the blower, the more load you have. When you let the tensioner go after installing the belt, it shouldn't move much. If it does, again, you need a shorter belt. The way you're configured, you shouldn't need much other that a stock type belt. Grab a few in the size range you think you'll need. Take back the ones that don't fit.
06-17-2019, 07:32 PM
#7
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Just ordered the Gates K060975 (97.54" Length) belt and the 90mm pulley.
https://www.gates.com/us/en/power-tr...1/v/8552-02367
https://www.gates.com/us/en/power-tr...1/v/8552-02367