AaronR968

Very nice! That must have been about 2 years ago! Man time flies! Nice build btw.

DWalker

Jim I do apologize but I simply did not have time to take any pictures today, but I should be able to do so tomorrow.

nathanUK '81 930 G50

Jon, your diagram does not show which port on the wastegate to connect to. Is it the vent?

JBL930

The diagram was for a 993tt with actuated wastegates, i thought that the external wastegates worked in a similar fashion. Basically that there was a hose conected to the wastegate that was aslo connected to the manifold/throttle body/intercooler whatever, so that as soon as you reached a certain boost level then the spring in wastegate would open and bleed off the exhaust gasses, just like it does with an internal wastegate. I guess i'm missing something though, i would like that explained if someone would take the time.

nathanUK '81 930 G50

With the dual port external WG it has two ports, one for the lower port, often called the control port (below the diaphragm) and one on the top port, often called the vent port (above the diaphragm).
The spring determines the extra pressure allowed before the WG opens (therefore controlling boost level) compared to the actual air pressure. The turbo has a hose running to the control port.

RUF used a pressure regulator which got teed into the control port with the other connection of the regulator going back onto the WG vent port. So, the WG now thinks atmospheric pressure is higher so it allows the WG to stay closed until the additional pressure is reached. Spring+Reglulator=Boost.

The other way as you know (Turbosmart) is to use a simple spring loaded device which you place in between the turbo and the control port of the WG that does not open until the spring is overcome by the boost pressure.

I'm not actually sure how my EBC is meant to be plumbed in as the instruction are all in Japanese! I will try placing it in between the turbo and WG like the Turbosmart but I would think it needs to be like the RUF regulator. Needless to say my overboost switch will be there to protect my engine.

I have no idea how the newer turbo's work. I know the Sierra Cosworth turbo has some sort of mechanical linkage, I know two people that have them. One also has Nitrous

DWalker

I will hunt up some diagrams I have here and post them for you guys- there are a LOT of ways to control boost depending on your individual setups. With luck I can get it all together later today.

nathanUK '81 930 G50

Thanks, I would like to know exactly how to plumb my EBC rather than doing it twice

jimculp

Tracy made a couple of dyno runs yesterday. We're making decent power before the wastegate spoils the fun. He's making more runs today trying to iron out the EBC.

Here's the I/C setup nearly complete:


One of yesterday's runs:

jimculp

We had some improvement today by disabling the EBC completely. We still need to find a solution to keeping topside pressure on the wastegate- it's opening very early. These results are pretty impressive considering we're running at just over .7 bar- 426 hp to the wheels and 454 lb ft.

Anyway- here are a couple of pics from the day:

JBL930

Jim, that's really good power at 12.03psi (0.829bar) you must be over the moon
What are your plans for controlling boost?

A930Rocket

Very nice Jim. It's always better to have high HP at lower boost numbers. Makes for a longer life motor.

Does anybody make a larger intercooler like Jims to fit the stock manifold and a HFS (besides B6)?

jimculp

My tuner is going to try another brand of EBC to see if he can gain control over the boost. As he said yesterday, the last thing we want is to not have confidence over that aspect of the engine. He's still tinkering, so I'll let you know what happens.

But yes, I was/am very excited about how the car is running. BTW- your dyno sheet was more than impressive!

jimculp

Good point on the low boost level- sometimes we don't see the forest for the trees I suppose.

I'll pm you on the I/C.

jimculp

I ran the car at a DE at Roebling road this past weekend. The car ran well and strong all weekend (after the TB coupler was tightened).

I did have an area under the engine lid that continually got a layer of oil on it. The oil seemed to be coming from the BOV. It's not close to the amount that I got the last time I lost the turbo seals, but it's an amount that definitely drew my attention. I'll keep an eye on it and pull the I/C to see if there is too much oil in there.

SparkySounddog

Jim, I wish I had known you were in my backyard. I could have come out and introduced myself..and checked out your ride. Let me know next time.