How many running od cog with zl1 pump - Page 2 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

pdiddy · 03-12-2014, 07:34 AM

I am hoping that I make a little less than 10 psi with the OD cog and 3.8 It seems to vary about 1 psi from set up to set up. I believe the 3.4 up front with standard rear 1-1 will make just a little more boost then the od rear with the 3.8 front. I am told expect 3.5 psi of boost increase when going from the 1-1 to the OD rear with the 3.8 up front.

StreetSS · 03-12-2014, 07:43 AM

Quote:

Originally Posted by pdiddy

I am hoping that I make a little less than 10 psi with the OD cog and 3.8 It seems to vary about 1 psi from set up to set up. I believe the 3.4 up front with standard rear 1-1 will make just a little more boost then the od rear with the 3.8 front. I am told expect 3.5 psi of boost increase when going from the 1-1 to the OD rear with the 3.8 up front.

A friend of mine made 11+psi with that setup (3.8 w/headers) at sea level. He thought it was too much and converted to 1:1 cog until he cams it. He is now using the 3.4" with 1:1 and making about 10 psi. This is on an A6 so I am not sure if there is a difference.

Jason P · 03-12-2014, 09:51 AM

I have the overdrive, live at sea level. My car is cammed, ported heads and headers. Car makes 12 psi.

UNRIVALED SS · 03-12-2014, 10:14 AM

In order to get some additional clarity on the psi per combo. Please include front pulley size and engine displacement . Those are both critical variables for comparison purposes. Thanks

pdiddy · 03-12-2014, 11:29 AM

So after talking to magnasun and Mike at Superchargers Online the results on a 3.8 fron with the OD rear could vary from 9.5-12 it really depends on how the motor flows I am told the average gains when switching to the OD cog with longtubes is about 3.5-4.5 psi.

2010SSRSM6 · 03-12-2014, 12:16 PM

Quote:

Originally Posted by pdiddy

So after talking to magnasun and Mike at Superchargers Online the results on a 3.8 fron with the OD rear could vary from 9.5-12 it really depends on how the motor flows I am told the average gains when switching to the OD cog with longtubes is about 3.5-4.5 psi.

The OD cogs will give you about 3.5 pounds of boost over the 1:1 and a 3.8" pulley. The amount of boost you are going to see is going to vary based on your cam. If you are running an NA spec'd cam, you boost level will be higher than if you are running a cam that is spec'd for the blower.

On my setup, with the 3.8" front and OD rear cogs, 1.75" LTs and the Vmax TB, I was right at 10.5 #'s of boost at the top of the dyno pulls. With the 3.6" and a 95mm TB and ported snout on my maggie, I'm close to 12#'s of boost (depending on how accurate my boost guage is). Without the cam and headers, I'd likely be somewhere around 14-15#'s of boost for the 30-45 seconds the motor stayed together.

Ron_Robinson1 · 03-12-2014, 12:52 PM

Quote:

Originally Posted by Jason P

I have the overdrive, live at sea level. My car is cammed, ported heads and headers. Car makes 12 psi.

How long you been at 12psi, how much power is your car. Just curious.

Jason P · 03-12-2014, 01:31 PM

Quote:

Originally Posted by Ron_Robinson1

How long you been at 12psi, how much power is your car. Just curious.

About a year. Last dyno on a dyno jet was 637rwhp. I've done a few changes lately, putting it back on the dyno in a couple weeks to see where I'm at. The car runs really good where it is now, and I hope it continues to live with the stock bottom end. If it doesn't it will get a forged motor. I also have the LPE fuel pumps. I thought I should mention that.

old motorhead · 03-12-2014, 02:58 PM

Just to add a little clarity. The o/d ratio of the non cogged rear pulleys is 1.16. The ratio for the cogged o/d pulleys is 1.2. So....using the 3.8" front for both is the equivalent of going with a 3.27 front with the non cogged and a 3.17 front with the cogged pulleys. That would be the equivalents comparing to your current 1:1 rear drive. That may make figuring potential boost a little easier.

Ron_Robinson1 · 03-12-2014, 04:06 PM

Quote:

Originally Posted by Jason P

About a year. Last dyno on a dyno jet was 637rwhp. I've done a few changes lately, putting it back on the dyno in a couple weeks to see where I'm at. The car runs really good where it is now, and I hope it continues to live with the stock bottom end. If it doesn't it will get a forged motor. I also have the LPE fuel pumps. I thought I should mention that.

Nice setup bud, my car made great numbers on the dyno 11 lbs of boost but tickled 12 on the top of the dyno pull. I should of gone with a bigger fuel pump but settled for ZL1 pump, ADM FPCM, 80lb injectors, 93 octane and Meth for safety (also have a cam,LTs,ported TB, no cats). I put down 640/639 AFR was a lil rich 10.5-10.7 but methanol plays a part in that, my tuner was comfortable with this and so was I.

Everything looked good on the dyno through the pull and fuel didn't seem to be a issue yet. I'm just worried about this much boost, but others with PD blowers have been getting away with around the same numbers and amount of boost. I mean if it blows it blows and forged bottom end here I come.

StreetSS · 03-12-2014, 07:07 PM

Quote:

Originally Posted by old motorhead

Just to add a little clarity. The o/d ratio of the non cogged rear pulleys is 1.16. The ratio for the cogged o/d pulleys is 1.2. So....using the 3.8" front for both is the equivalent of going with a 3.27 front with the non cogged and a 3.17 front with the cogged pulleys. That would be the equivalents comparing to your current 1:1 rear drive. That may make figuring potential boost a little easier.

I am a little confused. Are there 3 available rear ratios 1:1, 1:1.16, and 1:2? What is the stock ratio? 1:1?

old motorhead · 03-12-2014, 07:16 PM

Quote:

Originally Posted by StreetSS

I am a little confused. Are there 3 available rear ratios 1:1, 1:1.16, and 1:2? What is the stock ratio? 1:1?

Stock on Camaros is 1:1 (both 3.25") on the rear. The non cogged o/d pulleys are 3.49 driving a 3.0 (3.49 divided by 3 = 1.163). The diameter of the cogged o/d pulleys doesn't matter as much as the teeth on each pulley. Similar to a chain drive. I don't remember the number of cogs on each pulley, but do remember the ratio is 1.2:1. So, yes there are three options for the rear drive. Five if you consider that you can change the o/d's to underdriven.

pdiddy · 03-12-2014, 07:29 PM

I think you meant 1.163 for your ratio

StreetSS · 03-12-2014, 07:31 PM

Quote:

Originally Posted by old motorhead

Stock on Camaros is 1:1 (both 3.25") on the rear. The non cogged o/d pulleys are 3.49 driving a 3.0 (3.49 divided by 3 = 3.163). The diameter of the cogged o/d pulleys doesn't matter as much as the teeth on each pulley. Similar to a chain drive. I don't remember the number of cogs on each pulley, but do remember the ratio is 1.2:1. So, yes there are three options for the rear drive. Five if you consider that you can change the o/d's to underdriven.

Thanks. I wasn't aware that there was a non cogged od. Sounds like going from a 3.4 1:1 to a 3.8 1:2 od to end up at 3.17 will do the trick for me. Maybe around 2 psi. A 3.6 would be 3.0 with the cogged od which is likely way too much boost for me. Let me know if I am off the mark.

03-12-2014, 07:34 AM	#15
pdiddy Drives: 2011 2SS Join Date: Jun 2013 Location: Kansas City Posts: 997	I am hoping that I make a little less than 10 psi with the OD cog and 3.8 It seems to vary about 1 psi from set up to set up. I believe the 3.4 up front with standard rear 1-1 will make just a little more boost then the od rear with the 3.8 front. I am told expect 3.5 psi of boost increase when going from the 1-1 to the OD rear with the 3.8 up front. __________________ 2011 2SS,fti th400, ECS 1500, Flex Fuel, Boost built 376, squash fuel system

03-12-2014, 09:51 AM	#17
Jason P Drives: 2011 2ss Join Date: Oct 2012 Location: United States Posts: 272	I have the overdrive, live at sea level. My car is cammed, ported heads and headers. Car makes 12 psi. __________________ 2011 2ss Ram twin plate ceramic clutch, Texas speed 418 LS3 235 /243 .621 / .624 cam, ported and polished heads with dual springs,magnum push rods, Hotchkis race pack, Stainless Power long tube headers with no cats, Magna Flo competition exhaust, lpe fuel pump, magnuson supercharger with overdrive and port matched blower plate, IW 8 rib pullies, AEM meth kit, id 850 injectors, 3 bar map, halltech cai, zl1 rear diff

03-12-2014, 11:29 AM	#19
pdiddy Drives: 2011 2SS Join Date: Jun 2013 Location: Kansas City Posts: 997	So after talking to magnasun and Mike at Superchargers Online the results on a 3.8 fron with the OD rear could vary from 9.5-12 it really depends on how the motor flows I am told the average gains when switching to the OD cog with longtubes is about 3.5-4.5 psi. __________________ 2011 2SS,fti th400, ECS 1500, Flex Fuel, Boost built 376, squash fuel system

03-12-2014, 07:29 PM	#27
pdiddy Drives: 2011 2SS Join Date: Jun 2013 Location: Kansas City Posts: 997	I think you meant 1.163 for your ratio __________________ 2011 2SS,fti th400, ECS 1500, Flex Fuel, Boost built 376, squash fuel system

03-12-2014, 10:14 AM	#18
UNRIVALED SS Drives: 2010 Camaro SS Join Date: Aug 2010 Location: El Paso Posts: 704 View My Garage	In order to get some additional clarity on the psi per combo. Please include front pulley size and engine displacement . Those are both critical variables for comparison purposes. Thanks

03-12-2014, 02:58 PM	#23
old motorhead Drives: Maggie blown LS3 vette Join Date: Aug 2009 Location: SE TX Posts: 1,490	Just to add a little clarity. The o/d ratio of the non cogged rear pulleys is 1.16. The ratio for the cogged o/d pulleys is 1.2. So....using the 3.8" front for both is the equivalent of going with a 3.27 front with the non cogged and a 3.17 front with the cogged pulleys. That would be the equivalents comparing to your current 1:1 rear drive. That may make figuring potential boost a little easier.