myskyon

well i have 2 87 turbos and one will drop boost at about 5500 rpms to about 12-13 from 17psi and the other will hold 16 till 6500in 4th gear though in 3rd it drops to 13 psi at about 5500. so i dont know whats up. i have read a lot of people say the 26/6 cant hold the boost to redline and what not and also that the reason for the turbo "s" getting the 26/8 was to hold boost to red a lot better than the 26/6. i know the "s" got other goodies too like larger sodium filled exhaust valves and a more agressive tunes among other things. i will have to do more testing on my cars to see what could possably be the cause. also FYI my car that drops boost has 208K and the one that doesnt has 154K both turbos never rebuilt. and both leak oil.

tyro

Glad I'd ordered a throttle body reseal kit, I'm going to need it.

With boost testing apparatus at 5 psi, the TPS side is blowing a nice gush of air.

Once that's fixed I'll hunt for more.

Auto_Werks 3.6

If you can hold 15psi to redline with the stock K26-6, then why the hell would Porsche change to a K26-8, and exchange more lag for nothing? Doesn't make any sense to me. I have personally never seen a stock turbo do that well near the redline... in several cars

JE_951

if the TB is leaking then you may have found your culprit...

I would also get a boost guage and WB02 set-up.

There are lots on the market but I love my LC-1 and it got top ranks on a WB test that I saw. $199 for the unit and you cna get a guage for an extra $50-$200 depending on what kind you get. OR you cna just use your lap-top for "testing" and then once you know its safe, un-hook the laptop.

Boost guages can be had for $35 too and can be mounted in your glove box if you dont want to buy a pillar pod or do a custom set-up.

That will help you ALOT, and give you a sense of safety so that you know when your motor is acting up.

tyro

No need to worry, I have an AEM wideband and an Autometer vac/boost gauge.

Went through a full rebuild last winter (minus the fricking throttle body seals).

Here's my engine before:



After:

JE_951

very nice! what steps did you take to clean/paint the motor? mine is dropping tonight and I plan on cleaning/painting also!

Is that the exhaust kit that was offered here for the group buy? I bought one too and cant wait to install all the new hardware.

JE_951

Not much, but this is what I have done so far:

tyro

Pressure washer, wire wheel, brake cleaner, hot tank, media blasted..you name it.

Had a friend plate a lot of parts - coolant tube has a nice gold color along with the lift ring and gasket shield in that photo.

The pan and cam housing were powder coated, the balance covers painted with high-temp paint. Cam gear cover was polished a little.

Yes, exhaust was a kit put together here. WELL worth it.

It was a good project, now if it would only run as good as it looks

pk951

They have some kind of magic turbo.

special tool

The 26 is too small for the 951 in all but street car applications - even then its weak.
It makes boost early to satisfy all the magazine readers who are worried about "lag"
Even most of the Porsche tuners make turbo kits to be early spool so they don't "lag"
And if you try to cheat physics - you will get other nasty surprises.
If you want power, you get lag - look at a trans am car, or even a nascar - top end. I guess that's lag.

You guys don't want to know how hard I blow by cars with little turbos - like GT30's - its a joke.
Nothing like a big turbo.
The 951 can spool Heap big turbocharger in time with proper CAMSHAFT TIMING, ignition timing and afr, trust me.
A 7,200 RPM 951 makes similar exhaust gas energy to a 4g63 at 9,000 RPM - something to think about, girls.

Auto_Werks 3.6

ST,
Im not questioning your logic but my point was, why would the factory go to a laggier turbo, if the one they were already using had no problems holding factory boost to the redline... According to the posts here, a K26-6 would have had no trouble powering the turbo S, and it would have spooled faster. Doesn't makes sense to me.

special tool

yes - I wasn't responding to your post, just blabbering, as usual.

evil 944t

Thats the problem. All blabbering and no ugotz..

xsboost90

- they used the 26/8 to move the power from bottom end to top end- thats why the difference between the 26/6 and 26/8 was 30hp.

Auto_Werks 3.6

Dan, that makes no sense. What you are saying can only mean one of two things,

option 1 (which you are saying is not true): The K26-8 moved the power band to the top end by sacraficing more lag for the ability to hold ~12psi TO THE REDLINE, hense more area under the curve netting 30 hp. This being a feat that the K26-6 was not capable of.

or

otion 2 (only remaining choice): The K26-8 has more lag, taking away low end power, making the upper register feel faster. Netting a magical 30 hp out of thin air. This was the case because the old K26-6 was more than capable of holding 15+psi to 6750rpm, they just didn't, and they though extra lag would be a nice change of pace.

I'm not trying to be an *** (even though thats whats happening here), I just can't believe a K 26-6 turbo is capable of those numbers, and if it is I want to know where my 5psi went!


Ps. I'm wearing my magic hat!