RSS PLENUM INSTALLED...0-60 TIMES
Drifting
Joined: Feb 2006
Posts: 2,647
Likes: 4
From: Elk Grove, California
This is on the 99 996 and maybe other models as well.....Just watch out when you take the old plenum out and start messing around with the rubber boots on each side...they each have a small black tube that runs from the bottom of the boot back into the engine compartment. I'm not sure what they go to, but you can break them if you try to pull out the boots. After you get the old plenum out, look into the boots and you'll see the rubber tube sticking up in there. It's not that bad of a deal really....couple hours for a novice is all you need...and be patient wiggling the plenum in and out.
Also....did you folks see the RSS notice about the length of the four OEM 10mm bolts that hold the plenum to the throttle body? The OEM bolts are too long for the depth of the tap on the new plenum, and you need to use a couple of washers to keep the bolts from bottoming out. RSS is going to be sending out shorter bolts with the new kits. I just used a stainless 10mm washer stacked on a lock washer to take up the slack. If this info is a repost or has been previously mentioned here, I apologize.
BTW...for you folks who know Mfletch...or Mark...he went into some pretty serious back surgery today and was under the knife for about 7 hours....I'll be going to see him when he gets out of his morphine high.
Also....did you folks see the RSS notice about the length of the four OEM 10mm bolts that hold the plenum to the throttle body? The OEM bolts are too long for the depth of the tap on the new plenum, and you need to use a couple of washers to keep the bolts from bottoming out. RSS is going to be sending out shorter bolts with the new kits. I just used a stainless 10mm washer stacked on a lock washer to take up the slack. If this info is a repost or has been previously mentioned here, I apologize.
BTW...for you folks who know Mfletch...or Mark...he went into some pretty serious back surgery today and was under the knife for about 7 hours....I'll be going to see him when he gets out of his morphine high.
Instructor
Joined: Feb 2006
Posts: 114
Likes: 0
I have a '01 C4 and it took me about 45 minutes to do this install. For me the trick was loosening the hose clamps almost all the way and taking the two that were closest to the plenum off and sliding them onto the plenum before sliding the plenum in there. This allowed the two boots to flex more on both ends so I could push them all the way to the outside and allowed me to gently pry them further apart in the front (making enough room for the plenum to just slide in from the front at no angle. I didn't see the warning about the bolts but mine fit perfectly as is.
Haven't really had time to drive the car but within the first 30 miles after install I also notice the smoothness that others have noted.
hth
Jeff
Haven't really had time to drive the car but within the first 30 miles after install I also notice the smoothness that others have noted.
hth
Jeff
Last edited by jeff_c; Jun 11, 2007 at 08:30 AM. Reason: oops. typo.
Three Wheelin'
Joined: Mar 2002
Posts: 1,454
Likes: 2
From: Long Island , NY
Found the manufacturer's site.... http://www.innovativeprodesign.com/
Lots of good info inlcuding air flow test results for the intakes.
Bad news it that I don't see one for the GT3.
Lots of good info inlcuding air flow test results for the intakes.
Bad news it that I don't see one for the GT3.
Pro
Joined: May 2005
Posts: 540
Likes: 1
Originally Posted by Ed Newman
Found the manufacturer's site.... http://www.innovativeprodesign.com/
Lots of good info inlcuding air flow test results for the intakes.
Bad news it that I don't see one for the GT3.
Lots of good info inlcuding air flow test results for the intakes.
Bad news it that I don't see one for the GT3.
This is really interesting.
The stock unit flows 829 CFM
So how much air does the engine need ?
Assume a 3.6 lt. Its a four stroke engine (duh!) so the cylinders take in air every second crank rotation.
At redline (7500RPM) there are 3750 intake gulps per minute
Or and air flow of 3.6lt x 3750 = 13500 lt/min
This translates to 476.75 CFM
So the stock unit seems to allow almost 2x the max required airflow at redline.
Race Car
Joined: Aug 2006
Posts: 4,978
Likes: 10
From: San Antonio, TX
Originally Posted by Dr_KarlB
This is really interesting.
The stock unit flows 829 CFM
So how much air does the engine need ?
Assume a 3.6 lt. Its a four stroke engine (duh!) so the cylinders take in air every second crank rotation.
At redline (7500RPM) there are 3750 intake gulps per minute
Or and air flow of 3.6lt x 3750 = 13500 lt/min
This translates to 476.75 CFM
So the stock unit seems to allow almost 2x the max required airflow at redline.
The stock unit flows 829 CFM
So how much air does the engine need ?
Assume a 3.6 lt. Its a four stroke engine (duh!) so the cylinders take in air every second crank rotation.
At redline (7500RPM) there are 3750 intake gulps per minute
Or and air flow of 3.6lt x 3750 = 13500 lt/min
This translates to 476.75 CFM
So the stock unit seems to allow almost 2x the max required airflow at redline.
It is interesting that in the carb world, this always was the case also. Putting a carb with an airflow higher than what the "numbers" required gave you a little more peak hp over the "ideal CFM" the engine theoretically (sp?) needed.
Pro
Joined: May 2005
Posts: 540
Likes: 1
Its probably not just airflow but pressure drop.
If you had infinite compression ratio, then in the cylinder you would have zero PSI and atmoshpere is approx 15psi, so you need to fill the cylinders to a max of atmospheric pressure with a 15 psi pressure. any drops along the way would give you a less than full filling of the cylinders with air.
But if you calculate the pressure drop thru a 3" tube (like the inlet system) at the flow rates we have, its quite small (like .5PSI).
Obviously i have no idea where the major restrictions in the system are, but i would guess the valves (95mm bore ?? and 4 circular valves so they can be so big, and have a limited lift).
Anyway, this is really about tuning the pulses at this point isnt it... the inlet isnt smooth as the cylinders "suck" air for only 1/4 of the time and with 3 per side, the air flow is zero for at least 1/4 of the time on each bank... the air also alternates side to side doesnt it ??
Clever engineering can make use of the pressure resonances to make a very efficient system and certain revs
If you had infinite compression ratio, then in the cylinder you would have zero PSI and atmoshpere is approx 15psi, so you need to fill the cylinders to a max of atmospheric pressure with a 15 psi pressure. any drops along the way would give you a less than full filling of the cylinders with air.
But if you calculate the pressure drop thru a 3" tube (like the inlet system) at the flow rates we have, its quite small (like .5PSI).
Obviously i have no idea where the major restrictions in the system are, but i would guess the valves (95mm bore ?? and 4 circular valves so they can be so big, and have a limited lift).
Anyway, this is really about tuning the pulses at this point isnt it... the inlet isnt smooth as the cylinders "suck" air for only 1/4 of the time and with 3 per side, the air flow is zero for at least 1/4 of the time on each bank... the air also alternates side to side doesnt it ??
Clever engineering can make use of the pressure resonances to make a very efficient system and certain revs
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Michael S. Palmer
Race Car
Joined: Aug 2006
Posts: 4,978
Likes: 10
From: San Antonio, TX
Originally Posted by Dr_KarlB
Clever engineering can make use of the pressure resonances to make a very efficient system and certain revs
Three Wheelin'
Joined: Oct 2005
Posts: 1,806
Likes: 19
From: New York, NY
Originally Posted by Dr_KarlB
Assume a 3.6 lt. Its a four stroke engine (duh!) so the cylinders take in air every second crank rotation.
At redline (7500RPM) there are 3750 intake gulps per minute
Or and air flow of 3.6lt x 3750 = 13500 lt/min
This translates to 476.75 CFM
So the stock unit seems to allow almost 2x the max required airflow at redline.
At redline (7500RPM) there are 3750 intake gulps per minute
Or and air flow of 3.6lt x 3750 = 13500 lt/min
This translates to 476.75 CFM
So the stock unit seems to allow almost 2x the max required airflow at redline.
