HTA is good- same result as a standard 35r at 1.6 bar to say the least... is it worth the extra cash? IDK....
All these garret based turbos like boost so any tuner that has the ***** to turn up a stock motor to 1.7bar or higher and run a car on the dyno will come out ahead- that is a known fact.... you wanna control the TQ or even for it to come on 350 rpms earlier? go with a .63 A/R vs .82... and vice versa...

The Tial Alpha series are that 7 blade HTA.... they do good but I am sure there are better combinations if someone puts the R&D into it...
Recent activity of billets on Pcars has resulted in great results... however I must warn that those results reached near 2bar and it's at much higher boost levels then the what we are used to running on standard garrets, be it HTA or not...
I am not against any new technology... just prove it on a P car with safe boost levels... I said the same thing about HTA when it came out.. ironically I did go for it... Todd at proto did back to back testing on my car and they were pretty close...
Thus the only honest way to tell is to swap turbos while leaving everything else constant and running it on the dyno.... but that does not happen often....
just my opinion,
markski

 

Id have to say thats all pretty accurate info..

 

I'd have to agree.

 

interesting info gents

 

Now what would you consider "Safe" boost levels?

I routinely run 1.3 bar on pump fuel(93 octane) making anywhere from 560rwhp to 650rwhp(depending on the stup) with no ill effects. On the same token, We took powell's car up to 1.9 bar on a bone stock engine, with no ill effects. He has hit 2.0 bar on the street as well. He's been at that level for months now, and believe me when I tell you that he is anything but "easy" on that car

I said it before and I will say it again. The major factor in how long a setup will last is the tuning. I seriously doubt anyone will disagree with me there; but the second, only slightly less well known factor is the DRIVER! No missed shifts, no mechanical overrevs, and no stupidity. That combination will keep a car alive.

That said... The billet wheel technology really shines at the upper pressure ranges for reasons which have been covered ad nauseum. Psi for psi at the lower pressure ranges, it is equal to the cast turbine technology. We saw no real gains in spool or power/tq/cyl prs to justify the switch if you have no reason to make big power(or run high boost). If the setup on the car is well thought out and tuned, then in theory you could use a smaller turbo, at higher pressures, spooling much faster and making more power. Key here is tuning. The higher pressure you run in the lower revs will have a propensity for knock(especially on the 996). This engine is well suited and efficient at lower boost levels, but it is also quite suited to the higher pressures as well.

What has been taught as "gospel" in the Porsche community is not entirely accurate. Sometimes, it's even quite funny and I am surprised that no techies have dispelled the previous theories.

Justin

 

Tuning is EVERYTHING on these cars. The slightest bit of knock on a stock engine running very high boost can lead to disaster. Tuning in this market is soo far behind many other markets.

We now have no less then 3 cars running stock engine and 900+ crank hps. 2 cars are running nearly 2 bar of boost to get there. Proper (conservative) tuning is what is keeping these engines together.

As Justin said, Powell hasnt had a single issues and he's not very nice to his cars .

 

Hell... I don't even change the oil in my car. The way I see it is that until the low oil comes on, there is no need to worry!

 

We ran 1.8 bar a handful of times as well. C16 fresh plugs with afr meter etc.
But that was to see the limit.
If it works for you guys kudos to all involved.
Markski

 

diggin up old threads?

 

?Yea that was old news (1.9 bar).... his car makes a little more power than before at the same boost levels. I did limit the torque down by about 40ft lbs though. We made 889 uncorrected through a bone stock untouched engine. He's itching to get some new 60-130 times for everyone though.

Billet turbos are still the way to go.

Justin

 

At those boost levels sure... but like I said before, and this is only pertaining to my Hta gt35rs vs regular garrett 35rs experience.... they both did the same Hp on the same dyno at the same boost.... maybe the hta was 100 rpms faster... all that at 1.63 bar max.... I have no agenda for or against HTA ... I actually know the guys at FP... good people....

mark

 

I am learning much,thanks guys.

 

Exactamente... as was mentioned before, the billet turbos perform identically to their cast counterparts until you get to the higher pressure levels(on a Porsche with 58mm inducers, let's call that 2.0 bar plus). Unfortunately, Powell's engine is still stock, and we don't exactly want to test the limits before he builds it.

Justin

 

Justin so are you condoning 1.9 bar on a stock motor?

ya the powell has big nutts to crank her up that high , and hes building the motor if it does go ... but you know its only a matter of time till she lets go at those levels ..

 

The billet wheels performance start showing above 2.0bar. I tested mine up to 35psi so far and it was a scary ride I know I promised everyone to test the 40psi range but since I'm selling the car now there was no chance of doing it. It can be done if the heads are torqued correctly. Powell has tested the water with the stock internals with his much HP for sure. Great work Chris and Boost Logic. Art