I am not sure as to why this external wastegate approach is better to the OEM internal style. There is mention that the OEM system is restrictive Typically, an external wastegate is better on cars making tremendous power where it is harder to regulate boost, thus the external gates. What has been demonstrated here is that you can make your car over boost with external gates. You could have achieved the same thing by over adjusting your stock wastegates. To prove your theory of the OEM system being restrictive, run your system at the stock boost level or crank those OEM wastegates down to match the boost of your system, and then see the difference. Just a thought. This would give you a "real" comparison and not just a car that is over boosting and making more power due to running more boost. Just a thought

 

EVO... what about the fact of the Externals allowing exaust gasses out rather than having to push it thru the main exaust system.... This does seem like an added benifit? Is it true?

 

It all depends on the rest of the system and the power being generated. This can be tested as I mentioned in the above post.

 

There is alot of incorrect information being posted in this thread. Let me clear up some things. The external wastegates increase performance because of several factors. 1. They are larger in diameter and bypass more exhaust way from the turbine. 2. They dump this wasted exhaust out and to the ground bypassing the exhaust system. This reduces the flow through the exhaust system 3. Because of the first two items air flow through the entire engine is increased and exhaust gas reburn is reduced. This allows for more power. The little K16's on this motor cause for an incredible amount of back pressure called EGB. On this car is aprox 2.5 times the boost pressure when chipped. Measure it with a boost gauge if you want..The external gates reduce this pressure by getting rid of the wasted exhaust. Even at 14 psi the external gates make a great deal of power.

Clark Turner

 

"Clark" Have you tested the EGB with your system as compared to stock? Is the back pressure due to the size of the turbine wheel and housing? Have you tested the external gates at 14 psi as compared to the OEM wastegates at 14 psi and seen a difference?

 

Todd, feel free and come by for a demonstration. Would be a good product for you to work with. Your opinion and visual inspection is appreciated.

Dan

 

I don't need a demonstration. I have used external wastegates before I am interested in you sharing the results that actually show an improvement and not just showing a car that is over boosting

 

That's what I recalled on the old evo stage 5 kit. ( Buddy's Car) Right Todd?

 

Hey Todd, thanks for the congrats on us being innovative and doing something different. After the work, the successful tests, and a good insight to alternatives, we appreciate other companies trying to knock us down. We dont go around saying how your products have failed etc. So lets play nice and support each other and know that we each do different work for the better of the community.

If you had a new product I would drive the 10 mins to your shop to learn, but hey thats me. I will let Clark answer your inquiries.

 

Hi Todd, Long time no talk. Hope you are doing well. I have to get by the new shop and check it out.

To answer you question the EGP is high on these cars due to the little turbine section. The gates realy help to reduce this because this wasted exhaust is not being compressed in the turbine housing. Its being dumped to the ground. I dont believe the car is overboosting at these levels. Turbo charger effeciency is not linear. Just being 1.2 bar might be to much at redline does not mean that its not to much at 3000 rpm. In fact, the car loves this added boost and it shows in the power that is made all through the midrange. If this is to much boost for the customer you can simply swap the springs in the gates.

To answer your question, yes, we have run the 14 psi springs. However, They did not produce exactly 14 psi. They produced 12.9 psi. At this lower then chipped boost level the car made an additional 20whp and 20-30ft lbs of trq over internal gates at 14 psi or 1.0 bar. Less boost and more power.

Clark Turner

 

Not that you guys need anyone else poking in this thread but you are over spinning those K16s to death. They will die in short time. We have achieved the same result by simply preloading the gates and or changing the springs out. Unless you are running a stock muffler your exiting wastegate pressure would not be an issue. Again this will depend on the system you are running and its ability to exit the wastegate gases. Typical stock muffler runs about 6.6 lbs and your aftermarket exhaust will range from the worse 2.5 down to .9. So given that an internal wastegate will control faster since it is coming off of the turbine housing.

I have tried many of these theories both on 996TT and many 930 we have converted to twin turbos. Generally the end result is the internal wastegate can control it best at 20% duty on the FV and external gates tend to get sloppy because of routing and stream diversion. Often this causes lag when used in a setup like this with lower boost as well as overshoot.

It sounds cool as hell I agree, but from a functionality point of view the internal wastegates are going to be superior.

 

Just warmin' up you guys!

 

serious note! I am interested in this thread + & -

so keep it going please

 

I think Todd and I should meet half way and have a thumb wrestle contest.

Dan

 

996TT STEVO - We are confident in the product that if you could get the car here, we would do the install, the test and everything for free. If it did not make results, no charge.