spjuvern

of course but that’s not for this thread

997 tt/rs

what is your goal ?
bigger compressor will create more lag

spjuvern

The best to choice turbo for 450whp
and less lag

cobalt

It has become a super slippery slope but yes I am cooling my turbos using a tip radiator mounted in front of my second oil cooler using a small pump mounted in the frunk next to the electric power steering pump. The plumbing is a nightmare and finally gave up on cooling the WG's. They say it isn't necessary and trying to do so just over complicated an over complicated system.

It keeps taking longer and longer but getting closer to having the engine in the car and the finished plumbing completed. I miscalculated the space needed to use direct ignition coil packs. I wanted the headers a short as possible and tucked up into the rear of the car it wasn't until was done that I found I limited my space on the exhaust side and still needed room for heat shields so I had no choice but to use individual coils which added complication and expense. Lesson learned. WE also didn't need to go with stainless lines but it just seemed like the right thing to do vs all Silicone tubing. There are two sets of lines. One for the water cooling the other for oiling.


Every pipe takes time to bend and secure. Just praying it all works as expected.

Metal Guru

You can get to 425 fwhp with mostly bolt-on components and some weight reduction and from my experience that will make for a seriously fast car. If you want more, dip into that retirement fund get ready to write some big checks. The machine shop bills alone will make your eyes water. In the end you will create a car that will possibly end up killing you. So unless you need a car that will compete at Buntingthorpe or the Texas Mile, you are just throwing away your money and possibly your life. I recommend that if you can, drive someone's modded car before you come up with your plan.

spjuvern

Of topic but
My 965 have 385whp = 420fwhp today.
The engine is all ready prepare for the more power as it is full ported heads, intake, flame rings, racing cams, ARP bolts and more.
and regarding the driving experience i have spend my last 25 years driving powerful cars like dragracing 1000hp supras and timeattack 1000hp Porsches and a lot of fast road cars as I work for Ferrari.
so as said as it sounds my 965 is still going to be kind of slow car at 450 whp.

So now I want to find out what the absolute best option turbo to choose for now days for that engine.
I like the original idea so car will always keep CIS
right now it looks like Evergreen K27 7200 raptor
still is best?

997 tt/rs

Where are you located?

spjuvern

Sweden

Metal Guru

Congratulations for surviving driving cars with crazy horsepower. Your turbo must seem tame like a car your grandma would drive to church on Sundays.
I have an K29 compressor/K27 turbine hybrid turbo and it transformed my car. I don't have any more lag than I did using the stock K27-7200 turbo and I did drive them back-to-back before I installed my SC cams.
I'm skeptical about the Evergreen turbo. I'm not sure how much better it can be if I'm understanding what's different about it.
As for the best turbo, call Chris at Turbokraft. He's dyno'd a lot of equipment and is a good resource.
Since you want to stick with CIS, talk to Brian Boddart at Rarlyl8. He has experience with high hp CIS turbo engines and is hooked up with Flowtech, who mods fuel distributors.
If my engine had those mods I would abandon CIS and go to EFI. That will do more to liberate more power than changing your turbo ever will.

997 tt/rs

Chris is working with Charlie for many many years and he is a fan of raptot modification.

have you got details of your k29 compressor wheel? always bigger compressor wheel will gain lag. Bigger compressor wheels are better when running more boost....
Thanks

997 tt/rs

This is not my fastest car i ever had 🎃

spjuvern

do you know any turbo company in Europe that might be of interest?

Metal Guru

Compressor impellers are made of aluminum so they have to get a lot bigger before they affect lag. Boost onset is the same as it was when stock.
I'm running .8 bar, so that is not a crazy amount of boost.
I'm going to modify your statement slightly: bigger compressors are capable of running more boost as they can pump more air before they hit their choke point.
I haven't looked at a compressor chart for a K29 in a while but I know for sure that the stock K27-7200 was maxed out running .9 bar. Doing the bar napkin calculations showed that any attempt to run more boost put the compressor over the choke line. Running at 1 bar verified this as the car was not any faster. The compressor was pumping really hot air so no thermodynamic advantage in that.

spjuvern

i agree I tested 1- 1.3 bar and only gain 7 hp on my k27 7200

so I need a turbo capable of make more hp

997 tt/rs

Sure but there is also design of compressor and here manufactures did huge progress.
i believe k29 compressor is old design.
The Raptor modification uses new design billet compressor which is producing 10-15% more air and its lighter too.
here it is :