997GT2 Vaccum pump installation
#1
Rennlist Member
Thread Starter
997GT2 Vaccum pump installation
I was at my race shop and had a 997GT2 oil scavenge pump / vacuum pump installed on the car. I am extremely happy with this conversion as there is a huge improvement in brake pedal feel compared to the stock 996TT/GT2/GT3 stock vacuum set up. I have been running the complete 997GT3 RS 380/350 brake system on my car for the last 3 years including the 997GT3 brake master cylinder. Even though my brake pedal has been very firm compared to the previous 350/350 set up, it still did not quite have the same feel as a 997GT3. One of my gripes has been the fact that sometimes when I would transition very quickly from full throttle to max braking, my brakes would not have quite the bite they normally have and braking would require a lot of pedal effort. Basically, what was happening was insufficient vacuum and would manifest itself on very hot days when the air is naturally thinner. I am also at a 5000'+ elevation where the air is even thinner with density altitudes in the summer approaching 10000'. I went over this with the owner of my race shop and it was decided to install the 997GT2 vacuum pump. On the 997GT2/GT3/TT, Porsche installed a separate vacuum pump which is piggybacked onto the drivers side exhaust cam oil pump. On the 996GT2/GT3/TT, brake vacuum is tapped of the throttle body. I am assuming that Porsche added the vacuum pump to improve brake feel and consistency and remedy the shortcoming of the 996 brake system.
The conversion is a direct swap. The exhaust cam oil scavenge pump is removed and replaced with the 997GT2 oil/vacuum pump. The stock 997GT2 vacuum line is routed from the pump and plugged into the stock 996 vacuum line which is just left of the F-hose. It is a direct plug in as the connectors are identical. All that is left is to remove the stock vacuum line that connects to the check valve at the throttle body. We installed a rubber vacuum cap on the stock nipple of the check valve at the throttle body. You also need to install a small rubber vacuum cap on the nipple that goes to the exhaust bypass flap in the 997 cars (you can see the capped off nipple in the third picture). The vacuum caps can be sourced from NAPA. Total time of the swap was about 3 hours start to finish with everything essentially plug and play.
The result of the conversion is profound and makes the brakes feel identical to those of the 997GT cars. Pedal firmness is drastically improved along with improved modulation. This is a huge improvement especially for those that track their cars but it even makes a noticeable improvement in normal street driving. I can see why Porsche decided to go this route on the 997GT/TT cars. For those looking to maximize their brakes, this is a worth while upgrade.
996TT/GT2/GT3 EXHAUST CAM OIL PUMP
997GT2 PUMP EXHAUST CAM OIL/VACUUM PUMP
997GT2 VACUUM LINE
The conversion is a direct swap. The exhaust cam oil scavenge pump is removed and replaced with the 997GT2 oil/vacuum pump. The stock 997GT2 vacuum line is routed from the pump and plugged into the stock 996 vacuum line which is just left of the F-hose. It is a direct plug in as the connectors are identical. All that is left is to remove the stock vacuum line that connects to the check valve at the throttle body. We installed a rubber vacuum cap on the stock nipple of the check valve at the throttle body. You also need to install a small rubber vacuum cap on the nipple that goes to the exhaust bypass flap in the 997 cars (you can see the capped off nipple in the third picture). The vacuum caps can be sourced from NAPA. Total time of the swap was about 3 hours start to finish with everything essentially plug and play.
The result of the conversion is profound and makes the brakes feel identical to those of the 997GT cars. Pedal firmness is drastically improved along with improved modulation. This is a huge improvement especially for those that track their cars but it even makes a noticeable improvement in normal street driving. I can see why Porsche decided to go this route on the 997GT/TT cars. For those looking to maximize their brakes, this is a worth while upgrade.
996TT/GT2/GT3 EXHAUST CAM OIL PUMP
997GT2 PUMP EXHAUST CAM OIL/VACUUM PUMP
997GT2 VACUUM LINE
Last edited by powdrhound; 07-17-2014 at 11:26 AM.
#2
Cool upgrade! If I tracked the turbo more I would have to do something with the brakes for sure, Seems like your getting your car really sorted out.
Btw do you run NASA with Chris that has the TT3 red m3 at High Plains?
He came out to Miller for our last event and his car was really fast for a TT3.
How do your lap times compare?
Btw do you run NASA with Chris that has the TT3 red m3 at High Plains?
He came out to Miller for our last event and his car was really fast for a TT3.
How do your lap times compare?
Last edited by z06801; 07-17-2014 at 11:32 AM.
#3
Rennlist Member
Thread Starter
Cool upgrade! If I tracked the turbo more I would have to do something with the brakes for sure, Seems like your getting your car really sorted out.
Btw do you run NASA with Chris that has the TT3 red m3 at High Plains?
He came out to Miller for our last event and his car was really fast for a TT3.
How do your lap times compare?
Btw do you run NASA with Chris that has the TT3 red m3 at High Plains?
He came out to Miller for our last event and his car was really fast for a TT3.
How do your lap times compare?
High Plains Raceway (HPR) - full course
#5
Rennlist
Basic Site Sponsor
Basic Site Sponsor
How much?
__________________
Pete
Power. Lots is good, more is better, too much is just right...
'87 951, RIP
'00 996 C2 L92U AQ / IXAA IXRB IX54 M96/7.xx G96/7.88 M030 M375 M376 M436 M476 M601 M983 ... + 991 GT3 brakes, 997 GT3 sway bars, fully monoball'd suspension, Bilstein Cup Car coilovers, do88 Big Pack ICs. 10 & 12 x 19" BBS CH-R wheels with 265/30 & 325 /30 -19 MPSC2s.
Pete
Power. Lots is good, more is better, too much is just right...
'87 951, RIP
'00 996 C2 L92U AQ / IXAA IXRB IX54 M96/7.xx G96/7.88 M030 M375 M376 M436 M476 M601 M983 ... + 991 GT3 brakes, 997 GT3 sway bars, fully monoball'd suspension, Bilstein Cup Car coilovers, do88 Big Pack ICs. 10 & 12 x 19" BBS CH-R wheels with 265/30 & 325 /30 -19 MPSC2s.
#7
Rennlist
Basic Site Sponsor
Basic Site Sponsor
Thanks!
In Europe:
99710702272 Z TANDEMPUMPE ZYL.1-3 1.167,15 €
99710503670 Z UNTERDRUCKLEITUNG 141,04 € (not the part# in PDF-PET)
Ever thought about electric vacuum pump?
In Europe:
99710702272 Z TANDEMPUMPE ZYL.1-3 1.167,15 €
99710503670 Z UNTERDRUCKLEITUNG 141,04 € (not the part# in PDF-PET)
Ever thought about electric vacuum pump?
Trending Topics
#8
Rennlist Member
Thread Starter
I have not entertained an electric pump. Porsche did their homework on this so I see no need to reinvent the wheel.
To update this, I put over 80 hard track miles in 90F+ heat on the car today. The brakes performed flawlessly. Very solid pedal and totally repeatable over a 25min session. I'm thrilled with this upgrade..
#10
Rennlist Member
Thread Starter
#11
Rennlist
Basic Site Sponsor
Basic Site Sponsor
#12
Rennlist
Basic Site Sponsor
Basic Site Sponsor
No, it was not... But on the contrary to this:
Originally Posted by powdrhound
Nice find. Make sure it's the whole tandem pump as I believe you can also buy just the vacuum pump separate of the scavenge oil pump.
It was the scavenge oil pump without the vacuum pump. New pump, never installed, but where is the vacuum pump? Pic was nicely taken from the underside and seller confirmed the part number. Why on earth it's always British sellers on ebay I have similar problems with?? It's now returned, let's see if I get my money back.
Originally Posted by powdrhound
Nice find. Make sure it's the whole tandem pump as I believe you can also buy just the vacuum pump separate of the scavenge oil pump.
It was the scavenge oil pump without the vacuum pump. New pump, never installed, but where is the vacuum pump? Pic was nicely taken from the underside and seller confirmed the part number. Why on earth it's always British sellers on ebay I have similar problems with?? It's now returned, let's see if I get my money back.
#13
Rennlist Member
Thread Starter
Sorry to hear that Pete. Looks like one of those cases where it was too good to be true. I suspected that when you said you found it for 500 Euro. The whole assembly new from Porsche should be 1300-1400 Euro including the vacuum line which is obviously listed as a separate part number.
#14
Great post, this was one thing I noticed in my recent purchase. I have a 996 GT3 (350MM) setup up front. The pedal is ok, that's the best I can describe it. It just doesn't have the bite that my M5 had. My first thought was, well maybe I need a GT3 master cylinder/brake booster setup for the added pistons in the calipers and pressure from brake fluid. I may give this a shot down the road as I would like to track the car eventually.
#15
Rennlist Member
Thread Starter
Great post, this was one thing I noticed in my recent purchase. I have a 996 GT3 (350MM) setup up front. The pedal is ok, that's the best I can describe it. It just doesn't have the bite that my M5 had. My first thought was, well maybe I need a GT3 master cylinder/brake booster setup for the added pistons in the calipers and pressure from brake fluid. I may give this a shot down the road as I would like to track the car eventually.