racerxrick

I've seen 18psi and it DOES NOT drop at redline! The car goes like stink.

I do have a quality wastegate..

onspeed

And you're using a k26/6? I thought the reason Porsche switched to k26/8 in the S and 89's was because the k26/6 couldn't hold boost?

racerxrick

my friend did the mods when he owned it. When he bought the car it came with a pile of maintenance receipts. As far as we know it's the stock turbo. I was going to do a MAF conversion when I first bought the car. After driving it and reading up I'm not sure that I would benefit from that conversion due to the stock turbo.

I drove the car before and after the mods...in fact I was the first to drive it after the mods! I've had a number of drag cars and quick street/strip cars and my buddy wanted to see what i thought. DAMN is what i thought and now i own it!

From what I've read and from your post (from my limited experience!) it sound like exhaust should help you a bunch!

I can't remember which wastegate he swapped (was one of the last mods) but I know he went with a nice billet one and said that it held and controlled the boost much better.

NOTE: I don't make a ton of boost down low..but third gear on it holds rock steady when the car is under load.

Black51

^^^ I've got a similar setup so I'll chime in on that. My car hits 17 psi in 4th/5th gear pulls up to ~5400rpm on the original k26/6. I'm positive it's a 26/6. So ya, the k26/6's will hit over 16 psi. I think the reason why Porsche ever so diligently switched to the 26/8 was because if you look at a dyno chart comparing the 2, the 26/6 drops off like a cliff because it can't HOLD the boost as long as the 26/8. So it won't hold the torque and thus won't let HP climb much more. That's exactly what happens with my car past 5400rpm; time to shift up or she runs outta *****.

By the way, I'm running a LR DP wastegate, not currently running a MAF.

minho78

Russel Berry makes a nice chipboard. I was running APE setup and was running very lean in my case. I bought Russel's Multiboard and it's running very close to target eventhough it's a APE maf. My AFR attached (Manny Fernandes/Blue).

toddk911

Yes, I have. Obvioulsy there are other products and some that are top notch, but for me like you mention the 90% factor, it is not worth the great deal of extra funds for that 5-10%. Just my opinion. lol

slap929

minho78, what all has been done to your car?

minho78

Not much. APE MAF, Russel Berry chipboard, 3" catbypass.

Darwantae951

Then your turbo is not stock. The #6 hotside can't hold stock boost pressure (~11psi) to redline, let alone 18. I never saw boost bleed off with my old #8 at 15psi, but I never pushed it higher.

slap929

Modded, when is your project car going to be done? Need to post pics or better yet video of it.

Darwantae951

Engine is about ready to go in, I have a thread if you search under me. And there will be video once it's broken in and dynoed.

Euro951

My car with a fresh engine rebuild and a stock K26-6 can hold 11/12lbs of boost to redline easily with a Tial.

Darwantae951

I personally have never seen one hold till redline. Even with dualport wastegates. Lots claim it can, and lots say no. Video it and I'll change my mind.

slap929

Numbers just seem lower than I expected.

TurboTommy

It might be possible that with certain wastegates the stock turbo can hold more than 12 psi boost to redline.
But, the bottom line is that the stock compressor can only flow for a little over 300 crank hp (maybe even less if the ambient pressure it sees is less than ideal). So, it doesn't matter how much boost you're seeing at redline, that's all the power you're gonna get.
I know a lot of guys get real horny when they see their high boost reading at redline, but chances are their making very little more actual power than the guy witnessing the boost bleed-off thing. That high boost reading looks good on the boost gauge but it's all turned into heat and crazy back pressure.

The orginal poster said he'd like between 300 and 350 rwhp; so you have to upgrade the turbo.