Tial wastegate eBay

[T3rra]

I found a 38 mm tial wastegate on eBay, With adaptor plates for a 944 turbo. But the spring rate is 0.8 bar.

I'm pretty new 2 all this boost thingy. Is the spring rate right? I understand that the spring rate governs the minim boost, but ideally the closer macth to the intended boost rate run is best? To not exceed 10psi diffence

I'm looking 2 go stage 2 16/18psi, how dose that effect mpg? When driving normally? Do most bring the boost back 2 stock? If so a lower spring would be needed.

Iv done some reading but I just thought it be worth hearing for the guys who run it on the 944T in the uk.

I may have grasp this completely wrong. I'm all ears so school me ( on the spring rate not my spelling )

If anyone else intends on bidding or buying just let us know, would rather we didn't make it more expensive 4 are selfs.

Cars 250 turbo

 

[PSH]

ORIGINAL: T3rra

I found a 38 mm tial wastegate on eBay, With adaptor plates for a 944 turbo. But the spring rate is 0.8 bar.

I'm pretty new 2 all this boost thingy. Is the spring rate right? I understand that the spring rate governs the minim boost, but ideally the closer macth to the intended boost rate run is best? To not exceed 10psi diffence

I'm looking 2 go stage 2 16/18psi, how dose that effect mpg? When driving normally? Do most bring the boost back 2 stock? If so a lower spring would be needed.

Iv done some reading but I just thought it be worth hearing for the guys who run it on the 944T in the uk.

I may have grasp this completely wrong. I'm all ears so school me ( on the spring rate not my spelling )

If anyone else intends on bidding or buying just let us know, would rather we didn't make it more expensive 4 are selfs.

Cars 250 turbo

0.8 spring rate is ok, it's a lot stronger than a standard single port Porsche wastegate but that's a good thing. Porsche deliberately used a low spring rate, it keeps the power down ( so not as quick off the mark as the then 911 turbo) and it makes it easier for less skilled drivers. It also increases lag by a fair margin too, so 0.8 will help greatly with performance even if it was fitted to a single port wastegate, also it's still within the boost cut out protection although I suspect you may be over riding that soon.

There's always a compromise with fuel efficiency when increasing boost but that's the magic word 'boost', don't use it and the car will give similar mpg unless you fit larger injectors, however use that extra boost and yes you'll loose mpg.

Pete

 

[T3rra]

Thanks, I thought asuch with mpg, but I didn't no if it would run differnt off boost. Would a 1bar spring be better ? Would that increase the difference more in what you discribed? Jmg offer club man wastegate which is uprated tial. With plates that don't need safety wire.

What is saftey wire? Is it tie wire? Twist and it tightens up on it self? Feel free 2 laugh at me

 

[PSH]

ORIGINAL: T3rra

Thanks, I thought asuch with mpg, but I didn't no if it would run differnt off boost. Would a 1bar spring be better ? Would that increase the difference more in what you discribed? Jmg offer club man wastegate which is uprated tial. With plates that don't need safety wire.

What is saftey wire? Is it tie wire? Twist and it tightens up on it self? Feel free 2 laugh at me

I won't laugh at you I'm not sure what that means myself, when talking about plates and waste gates all that comes to my mind is shims which are used to increase spring rate, perhaps tie wire is used to secure them better but other than that I have no idea. 1 bar spring rate is a lot, IIRC I read years ago that it's not a good idea although I'm sure some have tried it, I may well increase my own for this latest round of mods but not decided on what. If this is your first venture into higher boost I wouldn't go over 0.8, that's already around 4 times the normal spring rate...


Pete

 

[T3rra]

From what I can understand is a wastegate regulates the boost pressure built up by the turbo. Which with out the wastegate would keep building? So how dose a turbo run out off steam? If it has the ability 2 create ever increasing pressures?

When a set pressure is meet, ethir by the wastegate spring alone or coupe with a manual or eclectic boost controller the waste gate opens preventing the pussures from increassing.

So a stiffer spring will only open at the minuim spring rate, but can be increased with mbc or ebc. Spring rate off the wastegate don't want 2 be with 10 psi off desired boost. But the closer the better?

Using a mbc or ebc can cause spikes and boost creep? So would it be safer 2 get as close 2 the boost levels intended with the wastegate spring, use the mbc or ebc 2 give the optioned 2 run lower( lowest waste gate spring will take ) and use the boost control 2 meet desired boost.

Now I think I'm understand all that? But with regards 2 lag and spool time. Dose a larger spring or higher max boost take longer 2 build up? Creating more lag or boost coming on higher in the rev range, but coming on harder?

So a larger turbo can make more power but take longer 2 build up. Wastegate sets the max puresure made by the turbo. Current Turbo is k26/8

But the weak spring in the stock wastegate holds the build up back?

My boost starts 2 build about 3k and by 3.5 I'm at full boost 1.85 ( 0.8 bar off boost ) on the dash display.

So what sort off build up would I expect running 16/18psi at stage 2

Less lag and more power, but what sort off rev range dose is full boost made?

Ecu and chip sets, how do these work?

Fuel mapping added set amount off fuel given 4 the set amount off air made by the turbo, klr monitors knock and over boost protection

Sorry if this all seems simple, I think I understand.

"If you can't explain it then you don't understand"

 

[T3rra]

Thanks

So 0.8 bar spring rate in the wastegate is good macth 2 run stage 2? 16/18psi

 

[PSH]

ORIGINAL: T3rra

From what I can understand is a wastegate regulates the boost pressure built up by the turbo. Which with out the wastegate would keep building? So how dose a turbo run out off steam? If it has the ability 2 create ever increasing pressures?

When a set pressure is meet, ethir by the wastegate spring alone or coupe with a manual or eclectic boost controller the waste gate opens preventing the pussures from increassing.

So a stiffer spring will only open at the minuim spring rate, but can be increased with mbc or ebc. Spring rate off the wastegate don't want 2 be with 10 psi off desired boost. But the closer the better?

Using a mbc or ebc can cause spikes and boost creep? So would it be safer 2 get as close 2 the boost levels intended with the wastegate spring, use the mbc or ebc 2 give the optioned 2 run lower( lowest waste gate spring will take ) and use the boost control 2 meet desired boost.

Now I think I'm understand all that? But with regards 2 lag and spool time. Dose a larger spring or higher max boost take longer 2 build up? Creating more lag or boost coming on higher in the rev range, but coming on harder?

So a larger turbo can make more power but take longer 2 build up. Wastegate sets the max puresure made by the turbo. Current Turbo is k26/8

But the weak spring in the stock wastegate holds the build up back?

My boost starts 2 build about 3k and by 3.5 I'm at full boost 1.85 ( 0.8 bar off boost ) on the dash display.

So what sort off build up would I expect running 16/18psi at stage 2

Less lag and more power, but what sort off rev range dose is full boost made?

Ecu and chip sets, how do these work?

Fuel mapping added set amount off fuel given 4 the set amount off air made by the turbo, klr monitors knock and over boost protection

Sorry if this all seems simple, I think I understand.

"If you can't explain it then you don't understand"

wow, there's a lot of questions in there..


In very basic terms a Turbo is a closed loop system which in theory will forever increase pressure until it goes bang and a waste-gate controls boost to stop that happening, but it's not as simple as that. Heat is a big enemy and the more pressure you false through, the greater the heat will become and then you have heat soak which drains that power. Add to this back pressure, to much boost to the standard exhaust system and you can destroy your engine. In extreme cases back pressure can exceed exhaust pressure with disastrous results, then your into reversion and tricks with valve overlap etc, etc.

Weaker spring increases lag as does a larger turbo due to how long it takes to spool. If your going to keep the k26/8 then lag isn't going to increase because of more boost, so build up will be similar to before unless you do a custom map which should help improve it.

Ecu/chip upgrade will ensure your fuelling is set to match your increased boost level. When you start playing around with boost you need to add an after market boost gauge and an AFR meter to ensure you don't go lean.

iirc when fitting DPW and chip you'll be over riding the over boost protection although will retain to some extent the anti knock.

Hope this helps a little, I have probably forgotten to include some important details, getting old , plus I'm be no means an expert but do have 14 years experience with modifying 944T's, others I'm sure will be able to explain things better than I.

This is in very basic terms...

Pete

 

[944 man]

My guess would be that by doing away with the cycling valve, you remove the ECUs ability to control boost pressure, but the KLR will still be able to retard the ignition if knock is detected.


Simon

 

[T3rra]

Thanks very much. Iv never own or worked on a turbo car b4. So I'm just trying 2 get my head around it all.

Stand alone boost gauge, are these displayed as part off an ebc? Or just some or none?

Thanks

 

[PSH]

ORIGINAL: T3rra

Thanks very much. Iv never own or worked on a turbo car b4. So I'm just trying 2 get my head around it all.

Stand alone boost gauge, are these displayed as part off an ebc? Or just some or none?

Thanks

An EBC will display boost but their screens are too small and usually they are placed out of direct sight. Ideally I'd want a stepper type gauge that you can set to warn you ( audible) when you reach your max intended boost and also records that info. Position it somewhere that's easy to see, I have mine fixed to my A pillar in a purpose built pod. This is for the optimum but to be honest any stand alone gauge will be far better than the one in the dash.

Pete

 

[JamesO]

ORIGINAL: 944 man

My guess would be that by doing away with the cycling valve, you remove the ECUs ability to control boost pressure, but the KLR will still be able to retard the ignition if knock is detected.


Simon

Correct, you'll also still get overboost cut as the ecu uses airflow to detect overboost, although most chips remove or change the limit

 

[944 man]

Do the better chips still keep the fuel cut? Thats something that Id be reluctant to lose altogether. Id also suggest that anyone who is increasing their boost fit a Knocklink, ideally disassembled and then rebuilt into their instrument binnacle. Detonation on boost will destroy your big end bearings in seconds and contrary to the misconception, you seldom hear anything.

Remember too that even though standard Turbos ran on three star petrol when launced, this is superior to our normal 95RON unleaded fuel now...

 

[TTM]

The reason why Porsche put a 0.4 bar wastegate spring was to maximise the operating range of the knock protection, should knock happen even at very low boost levels.

 

[JamesO]

ORIGINAL: 944 man

Do the better chips still keep the fuel cut? Thats something that Id be reluctant to lose altogether. Id also suggest that anyone who is increasing their boost fit a Knocklink, ideally disassembled and then rebuilt into their instrument binnacle. Detonation on boost will destroy your big end bearings in seconds and contrary to the misconception, you seldom hear anything.

Remember too that even though standard Turbos ran on three star petrol when launced, this is superior to our normal 95RON unleaded fuel now...

Judging by my knock counter, you're right I've never heard knock but the klr certainly has.

 

[944 man]

ORIGINAL: TTM

The reason why Porsche put a 0.4 bar wastegate spring was to maximise the operating range of the knock protection, should knock happen even at very low boost levels.

This interests me Tom, but it frustrates me too, because Im not getting it. Simple explanation appreciated.


Simon

 

[T3rra]

Well I won the wastegate £270. There was another bidder. Not to sure if it was the best choice. Jmg offer there club man wastegate £400 which is a new 38mm tial rebuilt with better then stock componets and flange machined 2 take 4bolt adopter plates better. will be a while yet, need 2 start sourcing the rest off the parts needed

Ebc/mbc
Chips
3bar fpr
Bov

Anyone got any off these?

 

[944 man]

Dont pay too much for the 3BAR FPR, because its a standard Bosch part, OEM on a number of cars.

 

[simkin911]

Scam75 has a brand new mbc for sale.

 

[scam75]

I do indeed! Brand new Promax kit with blue tubing.

Stuart

 

[T3rra]

Blue tubing don't really appell to me. Light to keep things looking... Well black

Black.silver and gold( zinc ) will be my colour scheme.

How much you looking for anyway?