Yes, your first line is correct. The rest does not make any sense to me. How does the turbine "have" to spin faster?

The turbine spins as much as the compressor...As long as your turbo is running in its sweet spot, how is it going to generate more heat?? If thats the case then you need to re size your turbo.

The heat is generated through the friction of small pipes. No back pressue and heat due to friction is what you want.

To break it down, the stock motor was rated at 220hp and now you are doubling that. How is it crazy to install a larger IC, pipes, t-body, intake and open up the head? It always blows my mind that everyone will argue 3,4 and now 5" exhaust sizes and nobody puts one thought to anything prior to the head. In fact, right now, forget about the IC and intercooler until the head is done properly.

Sorry for the long post. I went Porschefile on you, lol..

 

Think about how hard it is to blow through a small straw as opposed to a slightly larger one, and it really is as simple as that. You are allowing the turbocharger to not have to work as hard to generate pressure since it is no longer wasting energy trying to force a volume of air through a smaller area.

 

now picture at the end of the straw there is a needle hole (the head/intake/tb) doesn't help that much with huge pipes on stock stuff there.

now if the head has huge valves, extensive porting, huuuuge turbo and very little backpressure + bigger tb + intake, then I can see the need for huge air pipes.

I'm only using 2.5" pipes for air to&from new IC on my build since I'm leaving head stock only with upgraded valves (no money for a portjob or new bigger valves)

 

In your case, Thats fine, 2.5" is a start. Its better than 2.25". As long as your removing restrictions where you can aford it, thats all that matters. The less restriction/friction the better.

For others with huge turbo's headwork etc.. 2.5" IC pipes don't cut it. You can mask all those restrictions with a huge turbo but only to a certain extent.

 

Taken from Mr. Bell`s Bible

Pipe dia
2in--------255hp
2 1/4in---345hp
2 1/2in---450hp
2 3/4in---565hp
3 in-------690hp
3 1/2in----970hp


.........

 

More from Corky's book...you must keep the velocity of the airstream inside the pipe in less than 1/3 ( IIRC ) of the speed of sound, over that the drag increases substancially. Formulas for counting that are in the book. I discussed about this with a friend of mine, who has made his PhD in Science ( I hope I got that right in English, Dr. Eng. in German... ) in fluid dynamics computer simulations. He agreed that too and also said that every 90 degree angle is very bad, the airstream stops there like it hitting a wall and it has to be accelerated again after the bend. You can build some dividers inside the bend to divide and redirect the flow, but that's only partial help.
Too big is not good either...more volume, more lag.
IMHO the best solution would be a air to water heat exchanger inside the plenum and turbo feeding it directly. There's just not space enough.

 

with some creative use of some laminova rods that should be possible though pete, even in our cramped engine bays, it will require very high skill though.

 

I don't buy it. Just because you didn't gain anything doesn't mean intercoolers shouldn't be upgraded. Just because our head was modded doesn't mean it wasn't the limiting factor, what kind of head was it, what was doe to it. Also just because you put in a "bigger" intercooler doesn't mean its design was good enough to flow more, what kind was it?

Did you notice any difference in spool up?

Porsche decided that the stock intercooler was good for 220hp, I doubt they would use the same one for 400hp. I wonder what porsche would have done for a 400hp car?

I have upgraded the intercooler on three cars I have owned and I noticed better throttle response, quicker spool and more power on all of them. They were all german factory turbo charged cars. All were also larger intercoolers of the same design as factory in factory location but bigger., they all had the diamiter inlet and oulets as stock. None of them were front mounts, I don't like front mounts for a number of reasons. One car has a top mount, one a side mount and the last dual side mounts.

 

You dont have to buy it, not selling it Its just the dyno'd facts in my application. The head was ported by a mate of mine, stock valve sizes. Porsche didnt build the entire system to just support 220HP, not even the IC, my car made 400HP at the motor (365WHP), and the stock one was doing the job. I used the broadfoot IC, very well made piece.

 

Yup...

I am using a Laminova or WTA setup in my V8 twin turbo project

 

Anders covered this, but yes, the system is open loop, the head is at the end of the straw... a systems perspective must be taken, not just parts in isolation.

 

Thats the qualifer! You cant be wrong while you say that As long as it is... but the more volume the turbo has to essentially fill the harder it has to work to achieve (maintain) that pressure.

 

I can't understand why you think the turbo is working harder to fill an empty space? It can do that with no effort. The turbo has a harder time compressing more air in a restricted space with pressure pushing back on the compressor wheel.

No offense but if your not changing valve sizes on these heads, your head mods are very small. A good valve job is way better than stock but a good port and a valve size increase is night and day. Also, I'm not sure if you changed the cam with your " headwork" but that makes a hugee improvement.

ps- I wish you still had your 951. I liked all your write-ups.

 

All I have to say is I give up. I don't even feel like trying to explain anything any more. Stock is the best, Porsche built these cars perfect for a million horsepower from the factory, blah blah blah. Have fun.

 

From my experience helping test the various intercoolers that Lindsey Racing offers the dyno is NOT a very good indication of intercooler functionality. And a larger intercooler with increased flow does not necessarily mean better cooling of the intake charge. On the dyno with the header panel off in just one pull the intercooler goes from cool to the touch to so hot you can not keep your hand on it. The only place we saw any measurable differences was driving around with temp sensors before and after the intercooler and on timeslips at the drag strip.