Found Boost vs. Static CR chart
Thread Starter
Melting Slicks
Joined: Jun 2002
Posts: 3,060
Likes: 3
From: Dublin CA
Found Boost vs. Static CR chart
Finally found a PDF from the procharger site: http://www.procharger.com/pdf/Chevy.Prod.du.pdf
In that there's a Boost vs. Static CR chart. Seems I'm on the 'right' path with low static CR, but I need a lot more boost than I had expected. Translating the chart, a 10:1cr can have 8-12psi, a 9.5cr/10-15psi, a 9cr/12-18psi, and 8.5cr/14-24psi. One may want to add a safety buffer and drop the high numbers to the average of the range. This tells me that my 8.65:1 motor should have 14-18psi boost. Now, how to do that without cogs...
[Modified by blu00rdstr, 3:04 AM 7/7/2004]
In that there's a Boost vs. Static CR chart. Seems I'm on the 'right' path with low static CR, but I need a lot more boost than I had expected. Translating the chart, a 10:1cr can have 8-12psi, a 9.5cr/10-15psi, a 9cr/12-18psi, and 8.5cr/14-24psi. One may want to add a safety buffer and drop the high numbers to the average of the range. This tells me that my 8.65:1 motor should have 14-18psi boost. Now, how to do that without cogs...
[Modified by blu00rdstr, 3:04 AM 7/7/2004]
Le Mans Master
Joined: Sep 2000
Posts: 6,976
Likes: 527
From: Clouds Over California
Re: Found Boost vs. Static CR chart (blu00rdstr)
Now, how to do that without cogs...
[Modified by blu00rdstr, 3:04 AM 7/7/2004]
[Modified by blu00rdstr, 3:04 AM 7/7/2004]
If you don't have an F1R Procharger, than get one.
Andy's F1 made 18lbs of boost on his 409cid...he just switched out the pully to a 4.125" to make it around 14lbs of boost...imagine running a 4" pully with 8 ribs and making 18lbs of boost....I don't think you will have to worry about belt slippage with that setup...I don't think you will see 14lbs of boost with a 6 rib 3.85" pully on a D1....maybe on the dyno..but not on the street (I know because that was my old setup)...and especially if you are using the MMS brackets (I know because that was somebody else's setup and it didn't work either).
Melting Slicks
Joined: Sep 2002
Posts: 3,064
Likes: 95
From: MI
Re: Found Boost vs. Static CR chart (blu00rdstr)
Thats an interesting chart. The ATI chart says that I could run about 14psi (median of lower and upper ranges of 9.3 compression ratio) on pump gas (94octane). On propane or race gas, I would say ok...I'd get a little worried on pump gas.
I would love for any tuners to chime in with their opinions/experience. I would also love to hear what others are able to get away with on pump gas (boost, compression ratio, horsepower/torque, octane used, sc or turbo).
I'll start first...
Boost: 12 psi
CR: 9.25:1.
HP: 600 @ 5800
Torque: 598 @ 3800
Octane: 94
FI: Single Turbo (T76 GTS)
[Modified by Earl H, 8:37 PM 7/7/2004]
I would love for any tuners to chime in with their opinions/experience. I would also love to hear what others are able to get away with on pump gas (boost, compression ratio, horsepower/torque, octane used, sc or turbo).
I'll start first...
Boost: 12 psi
CR: 9.25:1.
HP: 600 @ 5800
Torque: 598 @ 3800
Octane: 94
FI: Single Turbo (T76 GTS)
[Modified by Earl H, 8:37 PM 7/7/2004]
Melting Slicks
Joined: Jul 2004
Posts: 2,844
Likes: 144
From: Northern Ireland
Im kinda new here, but have been browsing some of the FI LS1 forums for a while.
How is it these engines can take so much boost with such high CR's ??
Most turbo engines or FI in general would use under 9.0:1 CR with numbers around 8.0-8.5 being more common.
I'll be getting my LS1 engine very soon, and intend to twin turbo it, but I would have been aiming for around 8.0:1 myself.
Im in the UK, but I expect our pump fuel to be similar to whats available in the US, or close to it anyway.
Is 8.0:1 far too low ?? Id like around 800bhp, possibly a bit more. its early days I know, but it will happen.
I already have a couple of reasonable sized intercoolers from my old twin turbo rover v8, although these can be changed if needed.
I will only be using pump fuel, no additives, no alcohol. Possibly water injection should I need it, but Id rather not.
How is it these engines can take so much boost with such high CR's ??
Most turbo engines or FI in general would use under 9.0:1 CR with numbers around 8.0-8.5 being more common.
I'll be getting my LS1 engine very soon, and intend to twin turbo it, but I would have been aiming for around 8.0:1 myself.
Im in the UK, but I expect our pump fuel to be similar to whats available in the US, or close to it anyway.
Is 8.0:1 far too low ?? Id like around 800bhp, possibly a bit more. its early days I know, but it will happen.
I already have a couple of reasonable sized intercoolers from my old twin turbo rover v8, although these can be changed if needed.
I will only be using pump fuel, no additives, no alcohol. Possibly water injection should I need it, but Id rather not.
