1.0 bar spring, why only 0.8 bar on the clock?

[flightlead404]

Stock CIS motor, K26, 1.0 bar spring in stock wategate. All new seals and O-rings, good hoses and elbow connections, hose clamps etc. New BOV seals.

Boot gauge goes smartly up to 0.8 bar and stops, never goes over.

Is there something I'm missing?

[jeos]

it can be your gauge is not measuring accurately.
get the calibrated to be sure

[JFairman]

The list of possible reasons would be v e r y long.

Are you sure you have a K26?
More likely you have a 3ldz which is the original turbo in the car or a k27 which is the most popular upgrade.
The 3ldz is not a k26.

[patina]

Originally Posted by flightlead404

Stock CIS motor, K26, 1.0 bar spring in stock wategate. All new seals and O-rings, good hoses and elbow connections, hose clamps etc. New BOV seals.

Boot gauge goes smartly up to 0.8 bar and stops, never goes over.

Is there something I'm missing?

The factory boost gauge is not very accurate whatsoever.

[930/66]

Maybe your K26 (3LDZ) cant support 1 Bar?!

[JFairman]

Originally Posted by 930/66

Maybe your K26 (3LDZ) cant support 1 Bar?!

A K26 is not a 3ldz and either one will over spin and blow overheated air past 1 bar if the wastegate does not open.

Porsche put the 3K 3ldz on the 930 and they put the 3K K26 on the 944 turbo. I've heard they also put a version of the K26 on the 924 turbo.

FWIW, here's a 944 turbo K26 compressor map.

[930/66]

Jim

Thanks for the clarification!

Cheers

[T77911S]

i hate to admit it but that means absolutely NOTHING to me.

[Tug68]

I have a 1 bar with a k-27 and my boost gauge pegs at 1.

[JFairman]

Originally Posted by T77911S

i hate to admit it but that means absolutely NOTHING to me.

Never to late to learn, and you do seem to know your electrical stuff

[infraredcalvin]

Originally Posted by T77911S

i hate to admit it but that means absolutely NOTHING to me.

Heh heh, me too

[proffighter]

Originally Posted by jeos

it can be your gauge is not measuring accurately.
get the calibrated to be sure

My 1st thought

[T77911S]

Originally Posted by JFairman

Never to late to learn, and you do seem to know your electrical stuff

thanks always good to get a complement from you.
i am afraid this is one of those areas i will be happy to let someone else tell me what i need.

my turbo is on its way back from durabuilt now. its a 7006. i was trying to find out mods for it. i have heard of the k27/29 but not sure if that one is made from a 7200. i went with the stock rebuild trying to save money for a rarelyl8 header. i have a header now just not equal length.

[flightlead404]

Originally Posted by JFairman

The list of possible reasons would be v e r y long.

Are you sure you have a K26?
More likely you have a 3ldz which is the original turbo in the car or a k27 which is the most popular upgrade.
The 3ldz is not a k26.

It is most definitely a k26. I have the original turbo in a box.

The gauge could be inaccurate. What the gauge actually reads is not that important, I just want to make sure everything is good and I haven't screwed anything up in the work I did recently. Previously the BOV seals were completely disintegrated and other seals were weak so I think it was leaking. Certainly it is performing much better and the turbo on-boost is night and day better.

both the turbo and waste gate will be replaced in a year or so anyway, just looking for pointers in case I messed up

[mark houghton]

It sounds like you've adequately covered all the normally suspect areas re: low boost. If your car "feels" like it's getting full boost (per your comment "Certainly it is performing much better and the turbo on-boost is night and day better") then I would say you're gauge is off.

My current 930 struggles to reach .7 bar on the gauge, and I could just sign that off to bad gauge calibration, but I feel that the performance I'm getting is commensurate with the boost reading. In other words, I don't think I'm getting full boost. My BOV/boost recirculation manifold piston end seals are worn from the tell-tale sound of it clanking when on and off throttle, and I wouldn't doubt that that's my boost loss culprit.

I took delivery of this car 14 months ago and as we all know, each one takes a certain amount of effort to find all the gremlins. Currently running much better than on day one.

[IMR-Merlin]

I have a 1.0 bar spring in my car and hit 1.3 all day long.

[flightlead404]

Originally Posted by mark houghton

It sounds like you've adequately covered all the normally suspect areas re: low boost. If your car "feels" like it's getting full boost (per your comment "Certainly it is performing much better and the turbo on-boost is night and day better") then I would say you're gauge is off.

My current 930 struggles to reach .7 bar on the gauge, and I could just sign that off to bad gauge calibration, but I feel that the performance I'm getting is commensurate with the boost reading. In other words, I don't think I'm getting full boost. My BOV/boost recirculation manifold piston end seals are worn from the tell-tale sound of it clanking when on and off throttle, and I wouldn't doubt that that's my boost loss culprit.

I took delivery of this car 14 months ago and as we all know, each one takes a certain amount of effort to find all the gremlins. Currently running much better than on day one.

My butt says the boost is much better :-) The needle moves up to 0.8 bar very smartly, then stops hard, its not like it creeps up to .8 bar. I doubt my butt is calibrated well enough to tell the difference between .8 and 1.0 bar.

[930/66]

Originally Posted by IMR-Merlin

I have a 1.0 bar spring in my car and hit 1.3 all day long.

Sounds plaussibel if you have a Tial or similar

Tial Say:

NOTE: When ordering, if you have an aftermarket exhaust on your Porsche 930 you will want to order a spring ~.3 bar lower than your target boost level due to back pressure reduction

[IMR-Merlin]

This might have something to do with it.

[mark houghton]

Slightly on, slightly off topic: Another reason I think my gauge is accurately reporting true boost (.7) is that I haven't heard the WG open....or it's so quietly muffled with the stock WG muffler. I'm accustomed to a pleasant roar, since my last 930 I had removed the muffler and I can't really recall how it sounded prior to the removal.

One way to find out: Yank that sucker off of there!