I was running around 650whp on GTX3071r's.
Now have my engine apart for a winter upgrade, to be able to up the power to around 800whp. Sold my turbo setup and will probably put on something slightly bigger. Currently looks like EFR7163's will go on.

Now in the (expensive) process of sourcing all the parts I want in there.
Doing 12mm studs and Carrillo rods.
Other than that I will probably have the heads ported and also considering upgrading exhaust cams.
Many tuners here in Europe seem to upgrade exhaust cams above 650whp.
I would like to reach 800whp at around 26psi and I guess ported heads and good cams will help with that..
So now looking into either Schrick cams or having my std cams regrind.

But, those of you with experience on upgraded exhaust cams, what do you guys recommend?
Schrick offers 274 degrees/ 10,6mm lift.
Dbilas offers regrind 288 degrees/ 11,1mm lift
Other German company offers 296 degrees/ 11mm lift.

On a sidenote Schrick offers 292 degrees / 11mm lift exhaust cams for 997tt... From what I hear and see 996tt and 997tt cams are "same" so wondering of the 997tt cams from Schrick will actually work on 996tt also..

 

996tt and 997tt cams arent the same. may be able to use them but they are different. i have dbilas in mine a good bit cheaper than schrick cams. 800 on 7163 with rods and studs can be easily done without any head work or or cams. maybe save that money for a good brushless fuel system and some 1300 or 1700 cc injectors. and a clutch

 

The variocam setup is different on 997, I dont think they are interchangeable for the intakes, the exhaust might be. You wont need head work or cams to get to 1000. Be sure to post up some pics of the build. Did I inspire you to do this yourself with my build thread? I'm bolting up my accessories right now, shouldn't be long for me now.

 

So even though it is possible to make 1000hp on standard head and cams, I was under the impression that ported head and bigger cams would cause the turbos to have to push less.. So reach my 800whp goals at a lower boost. As long as other bottlenecks like Throttle body and y-pipe are also upgraded.
But if you guys say that head porting and upgrade cams doesnt make sence untill 1000hp, I wont throw money that way.

BTW I will use SRM 74mm plenum, TB and y-pipe.
Was originally going to use IPD plenum but I really liked that complete package from Sean.
Also heard of guys having problems with going from the factory T-design to the IPD Y-design. Apparently the IPD plenum lead to airflow being inconsistent across the cylinders. Cylinder 6 receiving to much air causing lean condition / knock..
SRM plenum, being T-design, I guess will not have this problem.
Anyone on here actually has first hand experience with this problem on the IPD setups?

 

Yes, will post pictures and updates as I start putting things together

 

well theres a big difference between 800 and 1000. if your goal is 800 with those turbos you can do this easily without head work or cams. if you want 1000 hp sure the added airflow helps a lot . but you can still make that power as long as fueling and tuning is addressed.

i run the srm plenum and 82 mm t/b but im on proefi so its much easier to tune for

 

Ported heads, cams, springs, retainers, and lifters. Thats almost 10 thousand worth of stuff if you want to go down that road.

 

I wasnt planning on going all the way down that road.
I was thinking light porting, and a set of exhaust cams that would still work with standard springs, retainers.
That would cost me around 2k in total..
Even cheaper if I go with dbilas regrinds..
What do you guys think of regrinds vs for example Schrick cams..?
Obviously regrinds are the cheaper route but they will introduce a smaller base circle therefore causing the hydraulic lifters to have to work in another range.. I guess since this is so widely used, there is no problems with that.

 

Not sure if you can use cams on the stock springs. Definitely do some light porting and a valve job. Just smoothing the casting flash and matching the transitions should get you some gains. Practice on a junkyard head if you need to. You should do the 997 lifters also. The 996 are a risk to fail so they redesigned them. They are pricey however, like $2600 for a full set. I got a set of used ones from prodigymb but it is a bit of a risk using used lifters on a different cam.

 

Also you need the trans rebuilt and fuel upgrades and bigger clutch.

 

Thanks,

I have a 9ff clutch setup ready to go in.
This is the clutch 9ff uses with his 800hp kits, so hoping that will hold.

I have COBB 1000CC and single 450lph pump.
Not sure if that will take me all the way to 800, I guess the pump is going to be on its limit?
So might have to also talk so Sean about dual pump setup..

 

Yup you need another pump and bigger fuel lines. Bigger injectors to keep the duty cycle down. Theres lots of upgrades you need. Pin your coolant lines also.

 

Welding coolant lines is on my list ;-)

 

Just few thoughts

Real difference between gtx3071 and EFR7163 should be marginal, go bigger or keep 71s
Dbilas worked good for some setups, dont know real gain tho, they work with stock valvetrain but dont push the rev limit too high

I did 816hp on superflow800 @1.6-1.65bar on pump+meth using gt3076, not gtx.. on stock engine with rods, studs and lightly ported heads, oem cams..

12mm studs not needed for 800hp, for 1000hp I would do 12mm as I had lifted heads running 2.2bar and almost 1000hp w 10mm raceware studs.

If you find a nice combo, let us know pls, I might do that later on the road, still prices for 911s are way higher that GTRs for example...

 

Don't focus on level of boost, it's a measure of restriction. Remove as many restrictions as you can, sounds like you have a good plan. I agree that doing a mild cleanup on the heads is a good idea if it's apart as apparently the TT cars had fairly rough ports compared to the NA castings. What are you doing for intercoolers? No alcohol right? Do the math on the injectors for the fuel of choice and don't go too big so you can idle the thing. Engine management? Transmission isn't going to be happy for long so plan for that. Very interested in how those turbos work out for you, I'm interested in them as well. Do consider upgrading the actuators as they're apparently not great out of the box - Sean knows what to do!