What did you do to/with your 944 today?

[Thom]

With the restrictive stock intake and à KKK style hotside I agree that anything else than the stock intercooler won't be much helpful, especially a poor set up like the SFR stage 2 which sort of fits but works more like a temporary heat sink rather than a proper set up considering how poorly the core is placed behind the bumper with zero ducting. In fact only a fraction of the core is exposed to air flow. When using a free-er breathing hotside however the engine does already benefit from a less restrictive intercooler like the SFR2, which is not ideal but at least removes the basic stock flow restriction. At least in my case my 8v engine had the most mid range punch with the stock intake, GTX3076R 0.82 and SFR2, though torque collapsed at higher rpm mostly due to the stock intake.
On the 16v though the stock intercooler is even more restrictive, the engine is just starving for more air flow at higher rpm.

[Tom]

With the restrictive stock intake and à KKK style hotside I agree that anything else than the stock intercooler won't be much helpful, especially a poor set up like the SFR stage 2 which sort of fits but works more like a temporary heat sink rather than a proper set up considering how poorly the core is placed behind the bumper with zero ducting. In fact only a fraction of the core is exposed to air flow. When using a free-er breathing hotside however the engine does already benefit from a less restrictive intercooler like the SFR2, which is not ideal but at least removes the basic stock flow restriction. At least in my case my 8v engine had the most mid range punch with the stock intake, GTX3076R 0.82 and SFR2, though torque collapsed at higher rpm mostly due to the stock intake.
On the 16v though the stock intercooler is even more restrictive, the engine is just starving for more air flow at higher rpm.

It's been too long to remember everything, but this wasn't the stock I/c with re-worked end-caps (SFR2?) but rather the big front mount one that sat in front of the radiator (along with big TB and SFR intake). Ducting and cooling aside, it had lots of flow. I have since increased the size of the hot side and reduced logged back pressure by a considerable amount, so that may be a factor as well, but my guess is the 8v head/cam were the biggest bottleneck at the time. Whether your I/C is holding you back by 150hp or not, a higher flowing I/c bound to help. Have you dyno'd the car to get a pre-i/c baseline?

[Thom]

Well yes, we were using the same SFR Stage 2 (SFR2) set up. It flows well at the cost of not cooling that well.
It is not necessary to dyno the car, I see things in the data logs already that clearly point to the stock I/C as the bottleneck.

[Tom]

Well yes, we were using the same SFR Stage 2 (SFR2) set up. It flows well at the cost of not cooling that well.
It is not necessary to dyno the car, I see things in the data logs already that clearly point to the stock I/C as the bottleneck.

On my car the SFR intercooler brought the temps down just fine, per my sensors, and was able to do more runs than the stock intercooler before seeing the temps climb. (And the temps came down sooner than with the stock i/c.) I also didn't have any engine temp issues with all that in front of the radiator like others reported. I ultimately took it out, however, because I thought the installation design wasn't Porsche-worthy and it didn't seem to make any additional power, other than being able to sustain the power for more runs without heat soak, which wasn't all that necessary for me on a street car. Your new engine may well exceed the flow limits of the stock i/c, but it seemed good enough for my 8v motor. What kind of power are you thinking you'll have? I've since installed a slightly bigger than stock i/c because it fit under the nose and was available....

[Thom]

I don't know, but I specced an IC that should support 600hp according to the fabricator. This is I think as much as the GTX3576R will support if I turn the boost up to above 23 psi, which is the sort of boost levels I have specced and built the engine for. However I expect the turbine housing to be the next weak link in the never ending game of balancing out restrictions, but considering how the engine runs already I am confident though that running it at 18 psi will be just good enough for real world usage, and long term durability obviously. I cannot imagine upgrading the turbine housing, as the 1.06 Tial housing is huge, would require work on the exhaust, and I like the mid range torque and response allowed by the combination of the 0.82 housing and the long stroke of the 88mm crankshaft. During my Summer tour I nearly took off while going 'a bit' fast on a very long straight... it's odd how this 16V engine seems to turn into 'russian mountains' roads that seemed more or less flat with the 8V engine.
In the end the goal has always been to build an engine that feels balanced and remains usable in all weather, regardless of how much it puts down. After all I only built this 16V engine to get rid of the obnoxious loss of breathe of the 8V engine above 5500rpm.

[Tom]

I don't know, but I specced an IC that should support 600hp according to the fabricator. This is I think as much as the GTX3576R will support if I turn the boost up to above 23 psi, which is the sort of boost levels I have specced and built the engine for. However I expect the turbine housing to be the next weak link in the never ending game of balancing out restrictions, but considering how the engine runs already I am confident though that running it at 18 psi will be just good enough for real world usage, and long term durability obviously. I cannot imagine upgrading the turbine housing, as the 1.06 Tial housing is huge, would require work on the exhaust, and I like the mid range torque and response allowed by the combination of the 0.82 housing and the long stroke of the 88mm crankshaft. During my Summer tour I nearly took off while going 'a bit' fast on a very long straight... it's odd how this 16V engine seems to turn into 'russian mountains' roads that seemed more or less flat with the 8V engine.
In the end the goal has always been to build an engine that feels balanced and remains usable in all weather, regardless of how much it puts down. After all I only built this 16V engine to get rid of the obnoxious loss of breathe of the 8V engine above 5500rpm.

I hear all that. I ran my car at 500rwhp for maybe 6 months, and ultimately turned down the boost to preserve the engine longer (and stop breaking stuff), and to balance out the car. Stretching for HP or quarter mile goals is fun and worthy, but at this stage in my life, I'd rather have a more balanced car running in it's sweet spot than push it to the Nth... Of course, I've seen installed the KW coilovers, so I'm hoping the new motor gets me back to previous highs without stress, and that the chassis is more up for the task now. With the original (worn out) shocks and springs, my car launched kind of like a 60's gasser.

[Thom]

Worn out original rear shocks can cause nasty reactions when driving over bumps in long curves. I always wondered how you were able to enjoy all that power with these!

[johnb]

Tom, what's your impression of the KWs? I have been considering those for a while. My shocks are not that old (installed Koni inserts around 8 years ago) but I've never been that impressed with them. The car is harsh on the roads we have around here, and still not particularly solid on the track.

[Tom]

I'm a big fan of the KWs. My factory shocks were completely shot, so maybe not a fair test, but going from that to KW's was dramatic. The KW V3's transformed the car honestly. I installed them per the instructions (retaining the torsion bar) and set them to a stock(ish) ride height and about the middle or the stiffness range. I also have the large 968 adjustable sway bars, and together it's just a different car now. It's compliant over bumpy roads without being super harsh (BTDT, no thanks), but the KW's took all of the wallowing out of the car in all directions and makes it feel so much more planted (the way you'd expect from a much harsher ride). It was so much better, that I immediately wanted to upgrade my brakes. The factory non-S brakes seemed plenty strong before when I needed plenty of time to set the chassis for corners, etc., but without even pushing hard I suddenly found myself wanting to carry speed into corners deeper than my brakes liked. I am not a big suspension guy, so don't have a lot to compare it to. It's more compliant than my 992TS over bumpy roads, and from a seat of the pants perspective it feels better to me than a stock 944 turbo S suspension (ride quality and performance). The only downside to the KWs is the cost -- they ain't cheap, but I plan to keep my car forever, so in the long run it was well worth the money to me....

[johnb]

I'm a big fan of the KWs. My factory shocks were completely shot, so maybe not a fair test, but going from that to KW's was dramatic. The KW V3's transformed the car honestly. I installed them per the instructions (retaining the torsion bar) and set them to a stock(ish) ride height and about the middle or the stiffness range. I also have the large 968 adjustable sway bars, and together it's just a different car now. It's compliant over bumpy roads without being super harsh (BTDT, no thanks), but the KW's took all of the wallowing out of the car in all directions and makes it feel so much more planted (the way you'd expect from a much harsher ride). It was so much better, that I immediately wanted to upgrade my brakes. The factory non-S brakes seemed plenty strong before when I needed plenty of time to set the chassis for corners, etc., but without even pushing hard I suddenly found myself wanting to carry speed into corners deeper than my brakes liked. I am not a big suspension guy, so don't have a lot to compare it to. It's more compliant than my 992TS over bumpy roads, and from a seat of the pants perspective it feels better to me than a stock 944 turbo S suspension (ride quality and performance). The only downside to the KWs is the cost -- they ain't cheap, but I plan to keep my car forever, so in the long run it was well worth the money to me....

Thanks! Interesting to hear that it compares well to a more modern car. They are expensive but as you say not really too bad long term.

One thing that concerns me a little is that I don't see an option for the Turbo S. Since you're supposed to keep the torsion bars, that would mean my car would be a bit stiffer in the rear than intended, since it's an 89 and has the Turbo S springs and torsion bars. But I have an adjustable sway bar too, maybe that would give me enough adjustability to offset it.