Porschefile

Don't worry, I've got your back ST. Don't forget guys, the stock 951 wastegate spring is ONLY a .2bar spring. That's weak. Also, from what I understand, the stock 951 wastegate is a push type valve, meaning the wastegate valve pushes outwards (the boost signal to the wastegate physically forces the spring/valve downwards). It wouldn't take much backpressure to move that as it's only a ~2.94psi spring. Most aftermarket wastegates operate exactly the opposite, and are a pull type setup. A pull type is a superior design, as it is physically impossible for exhaust back pressure to open the valve (another reason I'm a big fan of the SSQV). If there were any aftermarket springs available for the stock wastegate, I bet a stiffer one would help this problem quite a bit. Though, you might as well go with a Tial as it's just a better design altogether.

Just curious but, would a 26/8 have an extremely short lifespan at 21psi, with the proper fuel, tuning, and supporting mods? I think it would be cool to put out ~340rwtq for a couple of dyno pulls, or maybe a few short bursts on the street.

tommye

Very interesting info ! Especially the 2 dynosheets from Lart directly comparing same car with the 2 wastegates in question.

But why is the boost coming on so late in this car ? Specs ?

I believe that the original WG design with the exhaust pressure pushing at the back (valve stem) side of the valve head is there for safety - if boost control fails, there will still be a limit on the turbo speed/pressure.

The Tial, of course is reversed - exhaust pressure is applied on the front side of the valve, actually helping it to seal better.

I wonder what years of accumulated disrt/soot in the valve seal region will do to these WG:s ?

Now, has anybody out there actually tried an original type WG with reinforced (or even freshly rebuilt original) spring ?? How would this compare to the Tial ????


Cheers,
Tommy

pk951

Bottom line is why waste your'e time with the stock wg get a tial mbr and be done with it.

tommye

Well, some of us like to keep the car 100% stock or stock looking, some of us are racing in showroom stock classes, some of us might get into trouble with the insurance company if aftermarket performance parts is used. And, who knows how well a Tial will work 20 yrs from now??

There are many bottom lines.....

special tool

Yes, there are many reasons to use a stock wastegate.
Lindsey is making a "clubgate" which is a factory rebuild deamed legal in more than one sanction.

streckfu's

If you want or need to maintain stock, fine. But if not. the Tial is also rebuildable which the stock is not. If a part fails in 10 years on the tial, replace it. Have you priced a replacement OEM wastegate from Porsce? You could buy 4 or 5 tials for the cost....

For stock classes, the Club Gate is your answer.

toddk911

"If you put a real wastegate in this car, you will burn the headgasket first or second pull at that boost."

Even though his a/f is fine???

aeronautica86

i think what he is saying is that if he installed a better wastegate, the car would be able to build more boost due to the wastegate not bleeding it off so much - in other words if he installed a better WG and didn't adjust his boost controller he would see much higher boost levels, and at these levels his a/f would not be fine, thus blowing the HG

nize

lart; can you provide more specifics on the car setup for the last two dyno's ? also, why did they dyno at two different shops on two different equipment? it's not easy to compare the same car on different test equipment as they may be calibrated differently...

lart951

Nize, the first graph has 2 runs, one in 3rd gear and the other in 4th.
the car setup was: SFR Stage I turbo, 55lbs injectors, forge bov, test pipe, LR digital MAF, AFPR and guru shimmed wastegate (stock with shimms)
dyno run was performed @ 19psi with 15% of xylene pero gal of 91 octane pump gas

The 2nd run was exactly the same setup except that the stock wastegate was replaced with a 38mm Tial wastegate. Run was done @ 19psi with 15% of xylene per gal of 91 octane pump gas..

The shops are less than a mile away and owned by cousins the reason why I went to the other shop is becaused the 1st one was closed on that day.

nize

if you read my post, i never said that exhaust pressure does not open the wastegate, i simply stated that the stock wastegate is capable of building +25psi of boost, which is WAY MORE boost than what anyone with a stock motor/turbo could safely run.

the misconception is that the stock wastegate is so weak that it opens with LESS THAN 20psi of boost due to exhaust pressure. this is incorrect. although (at factory stock configuration) it does begin to open at even +1psi of boost, this is due to the cycle valve forcing the wastegate open (to prevent boost 'kick') and NOT due to exhaust pressure.

pk951

Well for some of you who want to stay with stock wg fine, but if you have no restrictions with rules, and so on, go with a tial wg.When you compare the two wg you can see the quality of the tial is much better. Stock wg new is 1200$ can.You can shim stock wg up to 7mm, but the spring is still 18 years old.

tommye

So, has anybody any experience with the clubgate ?

Clubgate vs. fresh stock WG with harder spring vs. Tial ?????

Cheers,
Tommy

nize

that may be true, but the stock wastegate is still capable of building +20psi of boost, even with weakened 20 year old springs. you can clamp the cv line to prove this on any stock car.

and i'm not sure if you want 340rwtq, it's kinda challenging to drive in the rain. or up steep hills. or around corners...

nize

the stock wastegate (with the factory stock configuration) opens earlier because it is forced open by BOOST pressure (from the intake side, via the cv line), not because it is forced open by backpressure (from the exhaust side).