997 GT2 Expansion tank on 996 engine.
#16
08-28-2010, 03:12 PM
Basic Sponsor
Palette used a 997TT plenum and it split where its glued together... hes running 1.7 bar of boost on our kit... it this 997 GT2 unit one piece ?
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2001 996TT 3.6L and stock ECU
9.66 seconds @ 147.76 mph 1/4 mile click to view
160 mph @ 9.77 seconds in 1/4 mile click to view
50% OFF ON PORSCHE ECU TUNING BLACK FRIDAY SPECIAL
2001 996TT 3.6L and stock ECU
9.66 seconds @ 147.76 mph 1/4 mile click to view
160 mph @ 9.77 seconds in 1/4 mile click to view
50% OFF ON PORSCHE ECU TUNING BLACK FRIDAY SPECIAL
#17
08-28-2010, 03:20 PM
Join Date: May 2009
Location: Dallas TX
Posts: 203
Rep Power: 32 
The *biggest* difference is the plenum volume (if the expansion piece) Inlet is 2.5" vs 3.5" on the 997 and 996 TT units.
#18
08-28-2010, 05:11 PM
Yes, 1 piece cast aluminum. The casting inside is about the same roughness as the adapter bit that bolts to the heads on the 996. It's rough, but wouldn't take much to clean up.
The *biggest* difference is the plenum volume (if the expansion piece) Inlet is 2.5" vs 3.5" on the 997 and 996 TT units.
The *biggest* difference is the plenum volume (if the expansion piece) Inlet is 2.5" vs 3.5" on the 997 and 996 TT units.
#19
08-28-2010, 05:36 PM
Right, which is why I'll post up my findings regardless how they turn out.
My hunch is that the GT2 tanks will make for a better 'street' car and the 997TT would make for better high end/ultimate power car. Since I'm planning to stick with nothing larger than a GT28 turbo, I'd like to concentrate on getting power under the curve flatter.
The Irony is that this velocity/vs volume keeps being 'learned' by automotive manufacturers. My first lesson was about 20 years ago when building a 351c. To make a 4v head flow better, restriction plates are placed in the heads. Seeing this done, I went with the 2v heads instead of the 4v heads and picked up nearly a second in the 1/4 mile. With the latest generation of Porsche engines, it appears they are moving toward the higher velocity theory. (go figure?)
I do think I'll bring the adapter bit to market for the EGR/air injection system; although I doubt I'd sell enough to justify the initial batch. This appears to be the 'biggest' hurdle so far. *IF* anyone has a pair of 997TT expansion tanks, I'd like to set them side by side to the GT2 (or close up pictures?)
Tim: What is a wye pipe? I assume y-pipe? I'm planning on updating that anyhow. The plenum is smaller for the GT2, I have one, but will make my own also.
Good points on the EGR. If I tap in a freeze plug, I'm sure it will hold, but a 3/8" pipe plug or custom 14mm(?) threaded plug would be better. I'll do it this way.
Pete: I'll PM you an email. Thanks in advance for any help!
My hunch is that the GT2 tanks will make for a better 'street' car and the 997TT would make for better high end/ultimate power car. Since I'm planning to stick with nothing larger than a GT28 turbo, I'd like to concentrate on getting power under the curve flatter.
The Irony is that this velocity/vs volume keeps being 'learned' by automotive manufacturers. My first lesson was about 20 years ago when building a 351c. To make a 4v head flow better, restriction plates are placed in the heads. Seeing this done, I went with the 2v heads instead of the 4v heads and picked up nearly a second in the 1/4 mile. With the latest generation of Porsche engines, it appears they are moving toward the higher velocity theory. (go figure?)
I do think I'll bring the adapter bit to market for the EGR/air injection system; although I doubt I'd sell enough to justify the initial batch. This appears to be the 'biggest' hurdle so far. *IF* anyone has a pair of 997TT expansion tanks, I'd like to set them side by side to the GT2 (or close up pictures?)
Tim: What is a wye pipe? I assume y-pipe? I'm planning on updating that anyhow. The plenum is smaller for the GT2, I have one, but will make my own also.
Good points on the EGR. If I tap in a freeze plug, I'm sure it will hold, but a 3/8" pipe plug or custom 14mm(?) threaded plug would be better. I'll do it this way.
Pete: I'll PM you an email. Thanks in advance for any help!
How funny with the 351c heads been down that road too, I remember that plate. It extended into the head cutting off the bottom half of the port In a mechanical piping system its called a wye because its not a tee. But yes I am referring to your "Y" pipe.
cvj,
I have seen a intake port that flowed 265cfm on a inline 6 and when I did the math on his 1/4 time the car was making over 1200whp... I wish I had the time and means to just build a few different motors with the same turbos and see what happens..
This is how we make more power by guy's talking about how and what works.
#20
08-28-2010, 05:39 PM
Registered User
Join Date: Aug 2009
Location: Houston Tx
Age: 38
Posts: 2,498
Rep Power: 185 Right, which is why I'll post up my findings regardless how they turn out.
My hunch is that the GT2 tanks will make for a better 'street' car and the 997TT would make for better high end/ultimate power car. Since I'm planning to stick with nothing larger than a GT28 turbo, I'd like to concentrate on getting power under the curve flatter.
The Irony is that this velocity/vs volume keeps being 'learned' by automotive manufacturers. My first lesson was about 20 years ago when building a 351c. To make a 4v head flow better, restriction plates are placed in the heads. Seeing this done, I went with the 2v heads instead of the 4v heads and picked up nearly a second in the 1/4 mile. With the latest generation of Porsche engines, it appears they are moving toward the higher velocity theory. (go figure?)
I do think I'll bring the adapter bit to market for the EGR/air injection system; although I doubt I'd sell enough to justify the initial batch. This appears to be the 'biggest' hurdle so far. *IF* anyone has a pair of 997TT expansion tanks, I'd like to set them side by side to the GT2 (or close up pictures?)
Tim: What is a wye pipe? I assume y-pipe? I'm planning on updating that anyhow. The plenum is smaller for the GT2, I have one, but will make my own also.
Good points on the EGR. If I tap in a freeze plug, I'm sure it will hold, but a 3/8" pipe plug or custom 14mm(?) threaded plug would be better. I'll do it this way.
Pete: I'll PM you an email. Thanks in advance for any help!
My hunch is that the GT2 tanks will make for a better 'street' car and the 997TT would make for better high end/ultimate power car. Since I'm planning to stick with nothing larger than a GT28 turbo, I'd like to concentrate on getting power under the curve flatter.
The Irony is that this velocity/vs volume keeps being 'learned' by automotive manufacturers. My first lesson was about 20 years ago when building a 351c. To make a 4v head flow better, restriction plates are placed in the heads. Seeing this done, I went with the 2v heads instead of the 4v heads and picked up nearly a second in the 1/4 mile. With the latest generation of Porsche engines, it appears they are moving toward the higher velocity theory. (go figure?)
I do think I'll bring the adapter bit to market for the EGR/air injection system; although I doubt I'd sell enough to justify the initial batch. This appears to be the 'biggest' hurdle so far. *IF* anyone has a pair of 997TT expansion tanks, I'd like to set them side by side to the GT2 (or close up pictures?)
Tim: What is a wye pipe? I assume y-pipe? I'm planning on updating that anyhow. The plenum is smaller for the GT2, I have one, but will make my own also.
Good points on the EGR. If I tap in a freeze plug, I'm sure it will hold, but a 3/8" pipe plug or custom 14mm(?) threaded plug would be better. I'll do it this way.
Pete: I'll PM you an email. Thanks in advance for any help!
i agree with you on watching the velocity/vs volume wars over the years but in a N/A its more important then a turbo vehicle as we want less resistrictions without turbulence right? other wise youd not be doing this mod
#21
08-28-2010, 05:48 PM
It has been several months since I had Neil at Performance Developments flow the 997tt splitter and tanks and the 997 GT2 splitter and tanks. If I remember correctly, the tanks on the 997tt and 997 GT2 are the same. The splitter is different.
#22
08-28-2010, 05:48 PM
Join Date: May 2009
Location: Dallas TX
Posts: 203
Rep Power: 32
Post 2 and 3 updated. More peeksures.
CJV: Your post in another thread is why I purchased this manifold. *not to mention, your research also backs up what I learned a while back about proper plumbing size. (though, I'm far from as sophisticated as you are about actually figuring it out) Thanks for the research and time to post this up!
Tim: Yes, those are the plates.
I'd like to talk about the EGR/Air pump system. This looks like any other egr/air pump system I've ever seen. it's just electric, not belt driven.
The question is: If I leave the solenoid in place, can I simply pull the air pump motor out, plug all 4 holes and plug the solenoid lines? I need to look at a wiring diagram closely, but I assume the pump runs off of a relay and the ECU(DME) only runs a check on the relay and not the actual amperage or wave pattern on the motor, I don't see any sensors that would indicate it's ability to 'check' if there is actually air pumping into the exhaust or not.
The next question would be: how sensitive is this engine to having the EGR system removed? Will any adverse problems arise without proper tuning compensation?
CJV: Your post in another thread is why I purchased this manifold. *not to mention, your research also backs up what I learned a while back about proper plumbing size. (though, I'm far from as sophisticated as you are about actually figuring it out) Thanks for the research and time to post this up!
Tim: Yes, those are the plates.
I'd like to talk about the EGR/Air pump system. This looks like any other egr/air pump system I've ever seen. it's just electric, not belt driven.
The question is: If I leave the solenoid in place, can I simply pull the air pump motor out, plug all 4 holes and plug the solenoid lines? I need to look at a wiring diagram closely, but I assume the pump runs off of a relay and the ECU(DME) only runs a check on the relay and not the actual amperage or wave pattern on the motor, I don't see any sensors that would indicate it's ability to 'check' if there is actually air pumping into the exhaust or not.
The next question would be: how sensitive is this engine to having the EGR system removed? Will any adverse problems arise without proper tuning compensation?
#23
08-28-2010, 05:50 PM
Join Date: May 2009
Location: Dallas TX
Posts: 203
Rep Power: 32 The 997tt and 997gt2 splitter is different. I have both here. One is roughly 2.5" and the other 3.5". I'll take photos and note part numbers on both late tonight or tomorrow.
#24
08-28-2010, 05:55 PM
Post 2 and 3 updated. More peeksures.
CJV: Your post in another thread is why I purchased this manifold. *not to mention, your research also backs up what I learned a while back about proper plumbing size. (though, I'm far from as sophisticated as you are about actually figuring it out) Thanks for the research and time to post this up!
Tim: Yes, those are the plates.
I'd like to talk about the EGR/Air pump system. This looks like any other egr/air pump system I've ever seen. it's just electric, not belt driven.
The question is: If I leave the solenoid in place, can I simply pull the air pump motor out, plug all 4 holes and plug the solenoid lines? I need to look at a wiring diagram closely, but I assume the pump runs off of a relay and the ECU(DME) only runs a check on the relay and not the actual amperage or wave pattern on the motor, I don't see any sensors that would indicate it's ability to 'check' if there is actually air pumping into the exhaust or not.
The next question would be: how sensitive is this engine to having the EGR system removed? Will any adverse problems arise without proper tuning compensation?
CJV: Your post in another thread is why I purchased this manifold. *not to mention, your research also backs up what I learned a while back about proper plumbing size. (though, I'm far from as sophisticated as you are about actually figuring it out) Thanks for the research and time to post this up!
Tim: Yes, those are the plates.
I'd like to talk about the EGR/Air pump system. This looks like any other egr/air pump system I've ever seen. it's just electric, not belt driven.
The question is: If I leave the solenoid in place, can I simply pull the air pump motor out, plug all 4 holes and plug the solenoid lines? I need to look at a wiring diagram closely, but I assume the pump runs off of a relay and the ECU(DME) only runs a check on the relay and not the actual amperage or wave pattern on the motor, I don't see any sensors that would indicate it's ability to 'check' if there is actually air pumping into the exhaust or not.
The next question would be: how sensitive is this engine to having the EGR system removed? Will any adverse problems arise without proper tuning compensation?
........ 
#28
08-28-2010, 08:03 PM
First, we are working with theory now. More fuel with more air equals more power. It can also lead to a quicker response.
I must qualify that I have not tried to utilize these parts as Brad is trying to do. I had a flow test and p-ton study done on the 996tt, 996 GT2, 997tt, 997 GT2 and the WC plenums to see if we could find out if there was another weak link. The reason was to determine in our case if a better designed intake from the Y-pipe to the heads was justified in our build. We wanted to know what Porsche might already know ..... there was an obvious visible difference. To explore the "tanks" was really no different from Y Pipes enlargement, larger TB's and larger/better flowing splitters. The big unknown that no one appears to have explored is the so called "tanks." At first glance the 997tt parts could almost fit into the 996tt parts. We wanted to check not only flow, but also balance as in looking for any negative pressure areas. We found some very shocking differences. Because of what we learned we decided to design our own intake which looks like this.
What Brad appears to be doing is exploring if he takes the better 997 GT2 parts and adapt them to his 996tt ... will he have an improvement? I believe he will if he can properly handle the fitment. Our tests proved the 997tt and 997 GT2 tanks and splitters both far outperform the 996 counterparts with the 997 GT2 parts outperforming the 997tt parts. They not only outflow but they also are far more balanced with little to no negative pressure areas.
I guess in layman terms, I believe Brad hopes to remove another weak link flow wise (tanks) and then add more fuel to balance out the additional air. As an alternative or in addition, better velocity should help with a faster responding motor.
Who knows, Brad may be on his way into entering the Who's Who.
Best of luck Brad.
I must qualify that I have not tried to utilize these parts as Brad is trying to do. I had a flow test and p-ton study done on the 996tt, 996 GT2, 997tt, 997 GT2 and the WC plenums to see if we could find out if there was another weak link. The reason was to determine in our case if a better designed intake from the Y-pipe to the heads was justified in our build. We wanted to know what Porsche might already know ..... there was an obvious visible difference. To explore the "tanks" was really no different from Y Pipes enlargement, larger TB's and larger/better flowing splitters. The big unknown that no one appears to have explored is the so called "tanks." At first glance the 997tt parts could almost fit into the 996tt parts. We wanted to check not only flow, but also balance as in looking for any negative pressure areas. We found some very shocking differences. Because of what we learned we decided to design our own intake which looks like this.
What Brad appears to be doing is exploring if he takes the better 997 GT2 parts and adapt them to his 996tt ... will he have an improvement? I believe he will if he can properly handle the fitment. Our tests proved the 997tt and 997 GT2 tanks and splitters both far outperform the 996 counterparts with the 997 GT2 parts outperforming the 997tt parts. They not only outflow but they also are far more balanced with little to no negative pressure areas.
I guess in layman terms, I believe Brad hopes to remove another weak link flow wise (tanks) and then add more fuel to balance out the additional air. As an alternative or in addition, better velocity should help with a faster responding motor.
Who knows, Brad may be on his way into entering the Who's Who.
Best of luck Brad.
Last edited by cjv; 08-28-2010 at 09:39 PM.
#29
08-28-2010, 09:59 PM
Registered User
Join Date: Aug 2009
Location: Houston Tx
Age: 38
Posts: 2,498
Rep Power: 185
#30
08-28-2010, 10:06 PM
Join Date: May 2009
Location: Dallas TX
Posts: 203
Rep Power: 32 I use to have a Ford cap, but learned about Jap cars in the early 90s and went back only once (look at my home page bedellracing and check out the Mustang project)
CJV: Thanks for the vote of confidence. You are correct on what I'm hoping to accomplish. I doubt you'll see me on the who's who list anytime soon. I'm way out of my league at the moment and the house isn't paid off. I honestly feel pretty darn over-whelmed with all the new German vocabulary. But heck, the only way I'll ever learn is to go in guns blazing and see what happens. The good part is that I have a garage full of tools and years of experience building street legal cars cars that people say are too difficult to build.
Photos of the GT2 and 997 TT splitters are posted up.