Greetings all.

After several years of 944 ownership, I decided to pull the trigger on a 951 that presented itself. (Pics to follow. Polished her up just in time for the weather to crap out today.)

First of all, let me beat you to the punch... "You did what?! You bought a 25 year old Porsche without a PPI?! Almost on impulse?! From someone who obviously is not as detail-oriented as an owner of a 25 year old Porsche should be?!"

Yes. Yes I did. Yes, I know it was probably a foolish thing to do. But the 951 beckoned. And she's beautiful. Black and gorgeous. And I know that despite the very appealing purchase price, she will probably cost me a bunch in the long run. Such is my affliction. Guilty as charged. Now that that's out of the way...

This being my first 951, I must admit to expecting a bit more kick in the butt with the onset of the boost. Just running the original boost gauge and have never taken her to WOT, but taking her up to 5K yields a reading of 1 bar. Idles just above .4. Should I be seeing more than 1 bar at 5K? Acceleration can feel a bit "bumpy" at times as well. I'm going to start with a general plugs, wires, cap tune-up and see where that gets me.

Thanks in advance for all of the help I hope to get here as I learn the world of turbo.

Coming soon, "What's that annoying chirping coming from the rear of the car that goes away when I depress the clutch?" Followed by, "Is that a binding sensation I feel occasionally in first gear and reverse?"

Thanks again!

 

Yeah you're not hitting full boost. 1 bar on the stock gauge is when you're at atmosphere. When you go past that you're in boost. I'd say check for vacuum leaks. Go wot and report back.

 

Sell it quick before it infects your soul.

 

In a strange and twisted way, it's good to hear that I'm apparently not getting full boost yet (I guess?). Had considered vacuum leaks as the culprit as well. Will take her out today and find WOT to see what I get. So if things were operating as they should be, what might I expect to read on the factory gauge when we start getting boost?

Too late.

Thanks for the inputs, and keep the expertise coming!

 

Stock, around 1.6 to 1.8, That is the measured pressure in the intake including the 1 bar of normal atmospheric pressure. That is why the gauge reads 1 bar with the ignition on without the engine started.

 

Congrats and can't wait to see the pics!

Two guesses on the chirp when the clutch is out (since mine does it and I think I may have it traced)...either a) torque tube, snce it only engages when the clutch is out or b)if you have bad mounts you may just be hearing the gears in the transaxle?? My understanding is they all freewheel.

Then again a chirp could be a little birdy telling you..."uh oh what have I gotten myself into!"

 

Took her out for a spirited run today, but due to traffic and safety concerns was unable to reach WOT. That said, we must have been damn close as we saw 6K on the tach. Boost Gauge may have crested 1 bar, but by less than a needle's width, and that was under some pretty hard acceleration.

After the drive, got her back in the garage and had a good look/listen under the hood. Heard what I thought to be hissing, which would indicate to me a vacuum leak. Couldn't quite pinpoint the source, but seemed to be towards the front of the engine.

Any other suggestions or guidance would be greatly appreciated.

And of course, the obligatory pics...

 

Welcome aboard! Since you clearly realize what you've done no point in going over that! I'm sure you'll find the 951 to be a blast most of the time and a royal PIA the rest of the time!
Have fun!

 

Wow she's a beauty! First thing I would do is replace all the inter cooler couplings, especially the TB to hard pipe coupler! IF/when it pops off you will heard a sound like rushing water and the car won't rev boost pass 4k! Ask me how I know!

 

mine wouldn't even idle. lol

 

Welcome aboard! My car did the same thing when I bought it. Here's the plan!

Try this: Using a small clamp (little plastic locking clamp that Lowes, Sears,etc has) pinch the vacuum line to the wastegate. Its at the rear of the intake and goes down and back past the bellhousing.

WARNING: Do NOT use WOT while clamped. Just use enough throttle to see if the needle will go higher than 1.5 or so on the gauge, then back off the throttle. This should occur at around 3K RPM or so. If the boost responds to this, avoid the temptation to enjoy it. Over-enjoyment of the new found boost could cause you to make a headgasket post. If the boost doesn't respond positively, go to www.clarks-garage.com get busy reading, so you'll understand more of what we'll be telling you.

Post back up what happens with the clamp.

 

Thanks for the great post, Ted.

I had already looked at the Clarks Garage procedure but was a little unclear with no pics. Your post has shed enough light on the procedure so that I should be able to give this a go later today. Understand that if boost responds, hardware components should be good. Does this include vacuum lines? Will certainly only press-to-test as you describe. I've got enough things to do without adding a head gasket project to the list.

Just out of curiosity, what was your fix?

Thanks again.

 

im guessing bad wastegate

 

I dont know that I ever nailed it down, exactly. I think it was the cycling valve, but I tore it down for alot of maint. At the same time I installed a manual boost controller (MBC from here on out), 951 Max chips, 3bar, etc. I did find some clear fluid in the line to the KLR, but I don't think it would have caused the issue.

Bottom line: Unless you're a purist, if the clamp gives it "boost gone wild", buy a MBC and be done with an expensive CV that probably has ugly wiring to it. The first time you pull the intake, you'll order vac lines and venturi delete. Its all easy stuff, and eliminates potential headaches down the road.

 

According to Clark's Garage, if the clamping of the line to the wastegate is effective it indicates all hardware components are good, correct? So if the wastegate is bad, I shouldn't notice a difference after clamping the vacuum line?

Thanks again to all. Grateful to at least have a test to conduct, but just narrowing down the direction in which said test should lead me.

Will clamp the line, take a ride and report back.