Porsche 993 twin turbo

[juuhanaa]

Hopefully i dont sound nitpicking, but it has a reason why it is called a turbo supercharger. On a well tuned car, I cant say how long headers or intake plumbing the engine has, without i have look under the bonnet.

[juuhanaa]

The short and big pipe is going to flow better than long and narrow, so getting the pipe to flow by making it longer doesn’t make sense.

Perhaps the most important statement in the debate that I would work on for my self, if the longer pipe doesn't make sense.



-juhana

[ptuomov]

The short and big pipe is going to flow better than long and narrow, so getting the pipe to flow by making it longer doesn’t make sense.

Perhaps the most important statement in the debate that I would work on for my self, if the longer pipe doesn't make sense.

The point of what I wrote is the following. You don’t make exhaust primary narrow and long to get it to flow better itself. It will flow worse with more friction and pumping losses. You make it long and narrow to make the _head_ flow better at the overlap, which will make you more power than what you lose with the pipe friction losses.

[juuhanaa]

A couple of things to note. I need to figure out the length before i change the size, and its not because of the friction loss of the tube. I got thinking i see no one else is taking a stand on this subject so i dont want to go on, but this may help you understand my point. The example i gave worked for a friend of mine last year on the alastaro circuit. Now i dont say its something you need, but the same friend is leading a series this year and people still dont understand what that car is, soo maybe length changes the flow, or maybe im just crazy?

[ptuomov]

A couple of things to note. I need to figure out the length before i change the size, and its not because of the friction loss of the tube. I got thinking i see no one else is taking a stand on this subject so i dont want to go on, but this may help you understand my point. The example i gave worked for a friend of mine last year on the alastaro circuit. Now i dont say its something you need, but the same friend is leading a series this year and people still dont understand what that car is, soo maybe length changes the flow, or maybe im just crazy?

I don’t think everyone understands what you’re writing. Is this car you are talking about a turbo car, sorry, a turbo supercharger car? Is it a turbo supercharger car in which three equally spaced 240 degree separated exhaust pulses are driving each turbo supercharger?

[juuhanaa]

Just a car where longer primarys flow more..

[k-works]

You are re-inventing a wheel.
You need to contact RS-Tuning (in Germany), get upgraded turbos as they’d recommend and cams. And you need a bigger intercooler.
Exhaust is a waste of money, you will result in 540 hp.
This setup is equal to RS-Tuning Turbo S upgrade, same as Gemballa. RS-Tuning has the program for std ECU. RS-Tuning did it for most tuners back in the day.

The rest is not needed.

Or get a kit from Turbokraft.
No need for head re-work on turbo engine.

Let’s say, I have a genuine 993 Gemballa 600 and genuine 993 Turbo S, 1 of 345 engines, upgraded by Freisenger Motorsport with a dyno tune by RS-Tuning. This thing eats C63 for breakfast on a dying clutch.

[ptuomov]

You are re-inventing a wheel.
You need to contact RS-Tuning (in Germany), get upgraded turbos as they’d recommend and cams. And you need a bigger intercooler.
Exhaust is a waste of money, you will result in 540 hp.
This setup is equal to RS-Tuning Turbo S upgrade, same as Gemballa. RS-Tuning has the program for std ECU. RS-Tuning did it for most tuners back in the day.
The rest is not needed.

Absolutely I am reinventing the wheel! It's a hobby. But, yes, very much interested in learning what has been done earlier and not reinventing the wheel square.

When you say exhaust is a waste of money, do you mean headers between the exhaust port and turbos or turbo-back exhaust? So far, my research indicates that there's very little benefit from switching away from the factory headers.

In contrast, there's a large power and reliability benefit from a lower-restriction turboback exhaust, mostly from reducing the catalytic converter restriction -- if the measurements that I've been given are correct, this is pretty clear from basic turbo math. Quicker spooling hotside on the turbos, the greater the benefit.

The stock 993 turbo intercooler is very difficult to improve upon without changing the wing. Do you have an intercooler solution that actually measures better than the stock intercooler and doesn't require the GT2 wing? So far, only the Secan+GT2 wing seems to beat the stock intercooler carefully sealed.

In terms of the turbos, which of the relevant turbo upgrade options would you recommend?
1) K16 turbo with K24 compressor wheel
2) K24
3) K24 turbo with K26 compressor wheel
Or something else?

So far, my research indicates that this car was originally designed for enough headroom to make 500hp at the crank relatively easily but making over 600hp for longer periods reliably requires a whole lot of changes.

[k-works]

Catalytic convertors usually have 3x cross-section of the pipe. If they are not clogged, they should not cause restriction. This may have a bit with a spool, but on air-cooled Porsche adding boost won’t help as it suffers from inadequate air charge cooling.

Once we bumped up the boost pressure on 964 Turbo 3.6 to 1.4 bar and had less power than we had with 1.1-1.2 bar. I noticed that intercooler never cooler down with increased boost pressure.
So that 0.2 bar was kinda fake pressure as only cooled air pressure is what counts. If you get 2 bar of hot air charge - that’s not good, haha.

I think turbo S intercooler is taller. Also Gemballa intercooler is about 1 inch taller. There’s a rubber sealed plate over the intercooler. When you use a taller intercooler, you use a thinner plate or remove it, this way it fits. You can ask Turbokraft solution, I bet they have something, just ask them to paint it black, hehe.

[ptuomov]

964 Turbo is a good car, I think it’s going to continue to appreciate in value. However, it’s a bit different from 993 turbo, mainly because of the following reasons: 993 turbo is a short exhaust manifold twin turbo engine controlled with a fairly sophisticated EFI system, where 964 turbo is a single turbo mechanical fuel injection engine.

The 993 turbo intercooler is excellent and the same as that is used in both European and US 993 turbo s. I think the racing GT2 versions got a bigger wing to accommodate the larger Secan intercooler. Correctly sealed, the stock 993 turbo intercooler matches or outperforms basically all aftermarket intercooler that fit with the stock wing, some people arguing that Andial’s intercooler bring a minor improvement over stock. There’s a lot of data posted on intercooler on Rennlist group.

Multiple experienced tuners have told me that while the 993 exhaust is very well designed, it has the same feature that all the 1990’s turbo cars that at peak power it will produce high back pressure. Numbers that I’ve been quoted are 10psi or 0.7bar at 500ho level. The long catalytic converter, even if not clogged, appears to be the largest restriction and the mufflers the second largest restrictions. This is second hand info, but from credible sources.

993 turbo will lower power even more aggressively than 964 turbo if temperatures raise above limits. Because of this, boost levels over 1.2-1.3 bar without major changes will simply increase fuel consumption without actually increasing power. The engine really wants to make 500hp sustainably with mostly stock components but everything will need to be changed to make 600hp sustainably and reliably.

Catalytic convertors usually have 3x cross-section of the pipe. If they are not clogged, they should not cause restriction. This may have a bit with a spool, but on air-cooled Porsche adding boost won’t help as it suffers from inadequate air charge cooling.

Once we bumped up the boost pressure on 964 Turbo 3.6 to 1.4 bar and had less power than we had with 1.1-1.2 bar. I noticed that intercooler never cooler down with increased boost pressure.
So that 0.2 bar was kinda fake pressure as only cooled air pressure is what counts. If you get 2 bar of hot air charge - that’s not good, haha.

I think turbo S intercooler is taller. Also Gemballa intercooler is about 1 inch taller. There’s a rubber sealed plate over the intercooler. When you use a taller intercooler, you use a thinner plate or remove it, this way it fits. You can ask Turbokraft solution, I bet they have something, just ask them to paint it black, hehe.