lart951

Tial 38mm is a dual port wastegate

LFA951

My stock wastegate starts to open at 3 psi, I guess that's why the car feels so much more explosive with a Tial, cause it opens at 10 lbs. much more delivery of pressure at the given moment...

myskyon

i am sorry but i still do not believe the wastegate is giveing you any more power at all un less your stock one it going bad. you compairison is not one they are diffrent dynos diffrent days every thing abou them is diffrent for a real compairison you would have the same day same dyno. just the wastgate is the diffrence. i have made some really good boost numbers on my stock wastgate. like say holding 18psi through to 5500 then droping to the 12-13psi line. and this is with a k26/6 turbo. now my buddy had the stock wastgate on his 952 (turbo s) and he couldnt hold 18 he would peak then just start droping. he tried to get me to get a tial. i dont need one my gate is good. i would say though if your gate is going bad then it is the best replacement. but to change it and try to call it a power incresing mod? i wont buy it running the same psi with ether one will generat the same power there is no way it could produce power. all it could to is give you back the power you were loosing by haveing a bad gate.

lart951

I knew this was coming, you got me that was a huge lie, I actually was running a Stage V To4b on the second sheet @ 35psi.

it was the same setup all i did was change the tial, this is the way it happened:

In my first dyno sheet, I had setup my MBC at 18psi, the dyno was done with the shimmed stock wastegate (aka Ultimate guru pos). When the tial was installed and I went for the 1st test drive, my vdo boost gauge was showing 24-25 psi of boost and I had to do 3 more runs to adjust my MBC down to 18psi. My stock wastegate was bleeding 6-7psi I was running 24-25psi of boost in order to substain 18psi. I hope that explanation helps.

Stock wastegate does bleed boost, you might show 18psi in your gauge but your turbo is probably working harder to substain the 18psi

LFA951

My wastegate is actually ok, doesn't bleed and holds 15 psi til redline, it's just that it does open at 3 psi and it builds boost slowly and not as fast as it would with an aftermarket WG, besides I've always heard that stock wastegates were designed to leak boost...

lart951

I don't know if what I am about to say makes sense but one of the major differences between the shimmed wastegate and the tial was the way boost was build, on the shimmed WG it kinda of rolled it went up and stayed there but it was soft, on the tial it hit very hard, it made my car turn sideways.

myskyon

ok i have a non shimmed wategate on my car. and with my EBC my boost comes on hard it can put my car sidways too depending on the situation. i know the tial is a very good wastegate. i am not denying that fact what i am saying is at a givin boost pressure it should not make any diffrence in power. there is nothing about it to creat more power: it doesnt offer less restriction, doesnt force more air into the intake, doesnt do anything except controll how much boost is made. thats it. now a failing gate will reduce power because you are not holding the boost pressures. hence less power. on my setup k26/6 turbo i have made the same about of power as a k26/8 at less boost with only the EBC, LR 3" exhaust, LR stage 2 MAF with mafterburner, and LR chips. and the car i was compairing was a 951S with same exhaust same chips stock intake system and he was running 18psi VS my 16psi he only had me by 9WHP somthing like 5000rpms but then his power droped off and my stayed flat you could see in the boost readings from the dyno that his boost was going up, down, up down. and mine was constant. i droped boost (beacuse of my small turbo be for he did) and i was making more power at 12psi than he was at 16psi at 6000rpms. now with that being said he got a new wastgate and a wolf3d setup and his car is now making somthing like 300whp with a larger turbo and a tial. he has a lot better boost control now with the tial than befor and like i do now. but did that make him any more power? i dont think so. be for his wolf, big turbo, and tial. he made about 275whp now after its up to 300whp and when i turn up my boost to match his at 18 we are dead even on the road. i have yet to put my car on another dyno. but last time i was not happy with the crew that did it nor do i believe the results. but back on subject.
my argument was just the fact that its a diffrent dyno and diffrent crew makes a huge diffrence my last dyno was 236whp and my friend i was just talking about was 245whp switch dynos and he is up to 275whp and that is with out doing any mods. so 30whp between dynos. that is a diffrence. so to properly find out if your new part "adds" HP you need to get a bace number with the old one then swap out said part then run the dyno at the same place on the same day. or else your findings are not accuret at all.

sawood12

It is widely speculated that Porsche did this on purpose to limit the 951's performance relative the the 911's of the day. Not sure if this is true but it does seem strange that with all of Porsches mighty engineering knowhow, attention to detail and striving for the ultimate that they would go and install something as fundamentally flawed as the single port wastegate.

A spring is not an on-off device. No matter what the spring rating you will still get a compression at relatively light loads and therefore this is why the stock wastegate bleeds boost - even if it was brand new. The only way to hold boost and prevent it from bleeding is to positively hold the valve shut, as with a DPW. When I fitted my DPW and set the max boost pressure to 0.7 bar (stock pressure is 0.75 bar) I got 239bhp (that's UK bhp which seem to be a bit smaller than US BHP's) on my otherwise completely stock car. Granted my old stock wastegate was a bit tired when I removed it but to gain near as damn it 20bhp over and above what it would have had off the production line 20yrs ago just goes to show how much bhp the single port wastegate is loosing you.

shortyboy

i believe all tial wg are dual port.

streckfu's

The Tial wastegate won't give you more power but will prevent you from losing the power the stock unit bleeds off. Yes your stock unit is good, as in functioning as intended but think of the difference if you didn't bleed off most of your exhaust and were able to hold boost to redline vs 5500rpms.

You, also, need to measure boost using a proper boost gauge. If you are only looking at the stock dash gauge, you really don't know what you making or holding.

Yes.

lart951

Did you read this;

Also the dyno shops are located blocks away, owned by 2 cousins same dynojets same equipment.

LFA951

I use an Auto Meter boost gauge, the stock one is a joke like the Saab one

myskyon

ok i am using a vdo vacume/boost gauge. and also I have never seen or even heard of a k26/6 turbo making more than 12 psi of boost past 5500rpms. the turbo just doesnt have the ability. now a k26/8 that will hold it.
lart951- was yourstock wastgate bad? if it was then your power increse is just reclaiming the power of a failing part. and the fact of the 2 dynos are at 2 diffrent shops run by 2 diffrent peopple even if they were run by the same person. diffrent dyno diffrent WHP. simple as that. no 2 dynos are the same.

streckfu's

You are correct. At those engine speeds, the 26/6 is outside of it's efficiency. Upgrade to a 27/6.

toddk911

Yea, 90% of "rolling off boost" is just stock turbos running out of steam.