K24 Wastegate setting experiment !

[Speedkan]

I'm waiting to get the wastegate boost kit from Evoms so as i didn't know how to waste my time i have played with my OEM wastegate getting some strange results.

I hope that somebody can find something interesting in this test as i really got very different results.

I have started from the custom setting which should be 4,2 mm from the end of the rod giving 0,50 bar setting.

This is the custom setting of Borg Warner but it's not the custom setting of the 996 TT which should be 10,0 mm from the end of the rod giving 0,70 bar setting.

So here begins the fun, as i already knew, with the custom setting no way to get more then 0,9-1,0 bar overboost even chipped.

1 Test: 14 mm from the end and around 0,83 bar setting.

The car runs good and the boost increases to 1,0-1,1 all the range.

2 Test: 17 mm from the end and around 0,93 bar setting.

The car runs better and the boost increases again to 1,1-1,2 all the range.

3 Test: 20 mm from the end and around 1,03 bar setting.

DON'T DO THIS !!!! NEVER !!! :o

As i begin to test the car i think... WOW, AMAZING,... the boost increased to 1,2-1,3 all the range but (and here begin the problems) probably the spring of the wastegate is too closed and starts immediately to fail.

I make 3-4 test in 4th-5th gear and what i see on my gauge is overboost increasing to an incredible 1,5-1,6 bar, the car really flies but probably fuel pressure is not enough and with 1,6 overboost it really goes too bad.

BETTER STOP THE TEST IMMEDIATELY !!!

At the end what i can say is that it's been very funny but very dangerous too.

IMHO with OEM wastegate you can stay between 14-17 mm setting but nothing more.

Hope somebody find something interesting !

[contigo]

To increase this boost as you did here you only played with the wastegates? nothing else right?

When you mention example:

1 Test: 14 mm from the end and around 0,83 bar setting.

The car runs good and the boost increases to 1,0-1,1 all the range.

What does that 0,83 bar setting mean? the result of the 14 mm of the waste gate?

I am also waiting on my EVO waste gate kit , tell me how did it work for you? what boost did you take the car to? and on what setting (measurement) did you leave it?

[Speedkan]

Hi contigo,

yes, the starting point was an ECU reprogrammed to use my old k16 turbos at their maximum possibility.

This means 0,9-1,0 bar which is the best a 996 TT can do with the original turbo equipment.

Then i have changed the K16 with the k24 and the result was:

Same map...some boost with a little bit more of turbo lag.

So it was necessary to upgrade again the setting of the ECU, but as i think you have already read on this forum, i couldn't get out more and i couldn't understand why, until i have read that i had to change the wastegates too.

This is the reason why, waiting from my EVO kit, i have begun to play with the OEM wastegates.

So, yes, the result of a 14 mm setting is 0,83 bar setting (0,83 bar is the preload of the spring inside the wastegate).

While the EVO wastegates comes with a preload of 1,0 bar with the possibility to set them at 1,2 bar and i think something more but it's better not.

Now i have finally got the EVO kit and i have set them at 1,1 bar, just finished to test it !

What i see is 1,2 bar overboost and 1,1 in the medium range to increase again to 1,2 at the max power rpm which is around 6000 rpm and some peaks of 1,3 in the range 6000-7000.

This happens in all the gear but i see it most in 3rd-4th-5ft while in 6th i see occasionally 1,3 overboost.

I suppose i can set them without risk at 1,2 to get some extra NM in the overboost zone but nothing more at 6000 rpm.

When the K24 blown 1,2 bar at 6000 rpm this means they are at the top of their performance.

If you need some extra informations, just ask, hope i can help you.

Regards

[contigo]

You have been of great help, I have on my car the K24 turbos but as you mention with the 0.9 boost setting I believe because it is the most I see pressing hard with peaks of 1,1 maybe sometimes when I take my foot off the gas. I am getting the EVO wastegates tomorrow and I plan to install them with the 1,2 setting as you mention, I also bought the EVO FPR Fuel Pressure regulator to be on the safe side with gas as the boost rises (don’t know if you did that also). Did you see a significant improvement with the new waste gates? If it isn’t too much to ask , please tell me the results from the old gates to the new. I also bought the EVO diverter valves and the new AIR system from them which I will install also at the same time.

[Speedkan]

You have been of great help, I have on my car the K24 turbos but as you mention with the 0.9 boost setting I believe because it is the most I see pressing hard with peaks of 1,1 maybe sometimes when I take my foot off the gas.

I believe that actually your real boost pressure is 0,9-1,0 bar, because tthe 1,1 you see when you take your foot off the gas is not real but only the pressure that the boost sensor sees when you close quickly the throttle before the diverter valves open. Sometimes i see 1,5-1,6 when i take off very quickly my foot off the gas.

I am getting the EVO wastegates tomorrow and I plan to install them with the 1,2 setting as you mention, I also bought the EVO FPR Fuel Pressure regulator to be on the safe side with gas as the boost rises (don’t know if you did that also).

Actually i have the EVO kit installed on my car set at 1,1 but not the 5 bar fuel pressure regulator.

It looks like the OEM fuel regulator works good at the moment but really don't know at 1,2 setting. I think that should be still enough but sure, imho, you are not wrong installing it.

Did you see a significant improvement with the new waste gates?

Yes, absolutely, before no possibility to go over 1,1 overboost with 1,0 in middle range and 1,1 with peaks of 1,2 at the max power rpm.

If it isn’t too much to ask , please tell me the results from the old gates to the new.

Now i see, after 1 week testing, 1,2-1,3 overboost, 1,1 middle range, 1,2 always at max power rpm (6000 rpm) and 1,2-1,3 peaks from 6000 to 7000rpm. (i say 7000 rpm and not 6750 rpm because i have moved the rev limiter higher of 300 rpm).

I also bought the EVO diverter valves and the new AIR system from them which I will install also at the same time.

I have bought the diverter valves from Forge UK which is closer to me and work great but you will not see improvement in performance as the OEM diverter valves are still working good. But with the new diverter valves you can forget about them for ever as they will work good even with very high boost that make the OEM fail.

About air system, no information, as i'm still mounting the OEM one.

Bye

[contigo]

My friend I decided to play with the waste gates (old) also before I install the new ones, Questions:

1 Test: 14 mm from the end and around 0,83 bar setting.

The car runs good and the boost increases to 1,0-1,1 all the range.

What do you see when you do this test on the gauge of the car? 0,8 or 1,0? I just did it and saw 0,8

On the 10,0 mm from the end of the rod giving 0,70 bar setting.

I saw 0,7 are these numbers right? Going on the 17 mm next

But still I wonder are you seeing the number on the setting on your gauge or the other higher number? If so I have something wrong…..

2 Test: 17 mm from the end and around 0,93 bar setting.

The car runs better and the boost increases again to 1,1-1,2 all the range.

[Speedkan]

When i have made the first test at 14 mm rod setting when i say that the boost increases to 1,0-1,1 i mean this is the value i see on the gauge of my car.

In other words, a 0,83 bar preload setting of the spring inside the wastegates gives a result of 1,0-1,1 on the gauge.

And a 17 mm setting means a 0,93 preload setting of the wastegates and a result of 1,1-1,2 on the gauge.

But to know if there's something going wrong in your car, and i don't think that you have something wrong, i need to know if your ECU is original or not.

If you are starting from an original ECU i think that what you get is correct.

My starting point was a reprogrammed ECU that with K16 turbos was able to give me a 0,9-1,0 bar on the gauge with a 10 mm rod setting of the wastegates giving a spring preload of 0,7 bar and when i have upgraded my car with the K24, using the same map gave me the same results.

So you can see that our starting point are different:

Your car starts from a rod setting of 10 mm and a gauge pressure of 0,7.

My car started from the same rod setting and a gauge pressure of 0,9-1,0 gotten with a flashed ECU.

My opinion is that with the programmation of the ECU we can get, no distinction between k16 and k24, max 1,0-1,1 bar pressure on the gauge but if we want to go over there's no other way that play with the OEM wastegates with all the problems that we know or change them with the wastegates boost kit which creates a new starting point for new and higher regulation.

But don't forget that with K24 turbos you will never get more then 1,2-1,25 bar at 6000 RPM, this the maximum air flow that they can supply, not 1 liter of air more, but in the overboost range, i mean around 3000 RPM, you could theorically get 2,4-2,5 bar which is enough to destroy your OEM connecting rod in 2 seconds.

If i can tell you my experience, when you will have 1,3 bar at 3000-3500 RPM, 1,1-1,2 from 3500 to 5000 rpm, and again 1,2 at 6000 rpm with some peaks of 1,3 in the last rpm, with original internal engine parts, your car is near to be perfect.

But before you need to flash your ECU !

Bye

[contigo]

I think I had something wrong (leak) I just got the EVO parts installed last night and will test them today , at the same time we took all the hoses out and re check and tighten them, yes I have Gemballa DME reprogrammed .

I am going to use the gates with the 10 mm the instructions say and see what happens

I also installed a new plenun and 75mm TB, I will tell you the results

[contigo]

Installed the new plenum plus the 75 mm Throttle, new gates (evo), before I used to get the 0,9 boost smoothly (example direct from 0 to 0,9 . now I go to 0,4 and it stays there for some time and then at 3000 rpm or a little more it goes directly to 1,0, very aggressively) , now I have 1,0 boost but I feel a very strange push and sound when at 3-4000 rpm the big boost pushes the car direct from 0,4 to 1,0 , I don’t know if this can damage the car because I don’t feel a smooth push up but an aggressive push when it kicks in, in that range , is this what you feel in your car?

Edited September 3, 2007 by contigo

[Speedkan]

I don't think you have leaks!

Ok, your ECU should be perfect, but the way your engine runs is not good !

My car actually runs with 1,3 bar overboost, 1,1-1,2 in the 3500-6000 RPM and 1,2-1,3 in the higher RPM, with the OEM internal parts.

Sure it's not smooth as before but still must remain the possibility to control the boost from 0 to 1,2 bar with the throttle.

It's not normal that it goes from 0,4 to 1,0 without having the possibility to keep it in a medium position ( 0,5-0,6-0,7...).

Imho you should check with great attention if the rod of the new wastegate is able to move freely without touching any other parts.

This could produce a similar problem to the one you have.

The problem should be in the way the wastegates work but in my opininion should be easily solved if you check with great attention the work you have done !

At the end remember that with the basic setting ( 3 turns of preload on the spring wich is a better way to regulate them instead of the mm measurement from the end of the rod) you will not get more then 1,0 -1,1 bar, to get the best you will have to preload at least 6-7 turns but goes step by step, it's better and safer !

Let me know!

[contigo]

Will play with the gates as you suggest, I also think that is the thing I have to look at , but my fear is with the new 75mm TB (maybe too much air???...), I think that is what I am missing to have the car perfect the low RMP high boost (in the 1,0 range), as soon as I have that solved I will try to push it up a little more like you have it in the 1,2 range I am sure in that range you must feel a big difference from 1,0. The problem is that I installed the gates and didnt leave enough lenght to pull it more so I have to take them out and leave more rod space for the screws in the setup, I am not paying attention to the mm setup but starting with the gates at zero and then moving little by little up in the setup (I think that is a better way to go, dont you?...)

[Speedkan]

Don't worry about your new 75 mm TB, air is never too much !!!

You will easily get 1,2 bar overboost playing with the gates and, sure, you will feel the difference !

0,2 bar boost more at 6000 RPM are about 50-60 HP more and lot of torque at medium rpm!

I had your same problem with the kit in the first installation, so i think you will need to make some works on the connecting rods to make them fully adjustable.

I'm not sure, but i think that the EVOms kit has the connecting rods of the wastegates just a little bit too long !

Finally, the way you want to set them up, starting from zero and moving little by little, is for me the best way to go.

Enjoy !!!!

Bye

[2002Gt2]

I adjusted my wastegates the other day. My car has a flash and a Europipe. I tried to set them using 12.5 psi and the wastegates should crack open. This should give you 1.1 with 1.2 spike. Unfortunately, I was getting 1.3 and 1.4 in fourth and fifth gear. I dialed them back and now I'm getting 1.1 and 1.2 in all gears. Although, I did experience some hesitation in fourth and fifth (It would not go past 1 bar) and then it mysteriously stopped. I then felt that you should be able to measure the rod tip to the nut to make sure that they are both equally adjusted, but the passenger side rod is slightly different than the driver side (Header is much closer to wastegate on the passenger side). So if I use a digital measuring tool and measure the exact same length for the rod are the wastegates equally adjusted?

[Speedkan]

Yes, they should be, but for the best way look at the "K24 wastegate boost kit" in the "installation support" of the EVOMS Website.

Bye

[contigo]

I had my ecu remapped, now with the gates (evoms) i was doing 1,1 boost and pulled them 2mm more and instead of seeing higher boost i dropped to 1,0 max boost

[rs38]

how is the experience after all?

I am still wondering how it is possible to set the limits of the pressure manually instead of letting it the motronic do by the bypass.

Normally ME7.8 has the tourque limits set and would use the pressure it needs for this.

does it mean, the map you used was without limits?

[wross996TT]

how is the experience after all?

I am still wondering how it is possible to set the limits of the pressure manually instead of letting it the motronic do by the bypass.

Normally ME7.8 has the tourque limits set and would use the pressure it needs for this.

does it mean, the map you used was without limits?

I also did an aftermarket wastegate mod. (not EVOMS). Actually what you are replacing is the spring. The stock springs just are not capable of holding the higher boost....probably an extra margin of error built in by Porsche. But the stock wastegates leave a lot of power on the table. Again if you tune the car properly, you still can maintain safety for your engine, while getting somewhere around 30-40 hp.

Edited July 17, 2008 by wross996TT

[Chuck Jones]

I should have come here and read this discussion thread before I posted the same basic question on Rennlist about the difference between adjusting the wastegate shaft nuts versus purchasing the "upgraded wastegate".

[Danyol]

http://forums.rennlist.com/rennforums/show...ad.php?t=291228

More Info than you want to know..

[Chuck Jones]

I ended up with Kevin's tune and his wastegate kit....installed compliments of ARD's knowledge and expertise (he installed his some time back). He used a belt sander positioned upside down, then handheld the wastegates and carefully applied pressure and revolved them over the belt sander watching for the telltale line to appear that tells you you've cut thru the rolled over edge. You don't want to cut too far or you'll grind off the lip on one side...and you need matching circumferences in order to install the CNC rings that hold them back together with the new springs installed.

ARD then had a home made pressure setup gauge setup (ala Rube Goldberg)running off his air compressor that ran clear tubing to each side....with a bleed hose. He held his finger over the bleed hose till the pressure eventually opened the gate, then noted the pressure on the psi gauge and adjusted the nuts until he got them to open at about 8.5-8.75 psi on each side...then set the locknuts and it was a done deal.....both wastegates sync'd to open at around 8.5 psi. This made it a lot more accurate in a manner in which you could actually SEE the point at which they began to open and set them accordingly.

ARD wrote this up in a DIY that explains it a hell of a lot better and more precisely than I just did. Given my level of automotive engineering expertise I would have to put in the disclaimer "Don't try this at home without proper supervision"...but with Kevin's tune and the wastegate spring upgrade kit, the car runs consistently at 1.1 and 1.2. Never have seen a 1.3 which suits me just fine.

Quite truthfully, these writeups that explain how to do these various project become clear if you've actually done them or have watched and seen them done, but for the less mechanically inclined, they're hard to visualize even though the author might think it's clear and easily understood.

Edited September 10, 2008 by Chuck Jones