carrera1999

Hello, I joined recently and have some technical questions about turbocharging the NA 1999 C2 Carrera. I do realize there are kits but If I could buy a $10000 kit I would have bought a turbo car in the first place so humor me here

First I understand the dangers of turbocharging a NA car as I have failed numerous times and succeded more times than failed. I also understand the design flaws of the 1996 996 3.4l engine.

I have owned Many Turbo cars starting with a Mitsubishi Tredia turbo (bet you have never had one of those). Dodge Shelby turbo's, Dodge Neon,Honda civic SI, Mitsubishi Starion, Eagle Talon etc. The latest was a 2010 Mazdaspeed3.

I Have built NA --> Turbo kits before and this will be a challenge but I was wondering if someone could help with some questions before I start.

1.) I am going to install a EGT gauge
2.)I will be installing a wideband 02 for tuning - are these accurate for the 996 or a better question would be does anyone make a good kit for this? I have used Innovate motorsports in the past.
3.) Obviously, A boost guage - Where is a good place to tap for this?
4.) Would you tap for the oil feed line at the oil pressure sender or ?
5.) I understand that the 996TT has a secondary oil pump I assume it is for scavenging oil from the turbo drains so that the oil seals are not damaged - Just wanted to confirm...I am thinking of sending the drain oil through a pump to a front mount oil cooler. If this is not done, do the oil drains feed into the oil sump pan or where is that done?

6.) I don't plan on a reprogram for the computer but rather a remote Rising Rate FPR I know I know - But this is a tried and true method for many cars including Mercedes aftermarket superchargers. The question is how is the fuel return done? there are many ways to do this one a Na to turbo conversion but I was wondering if any one had used this and where the fuel would be returned?

7.) Going to start with a 3 lb boost spring in an external wastegate and tune from there this will be a single turbo


Thanks AND If I have missed a thread that covers all of this - I am sorry but I did search

Ted


1999 C2 Carrera
2002 CLK 55 AMG
2005 Jaguar S-Type R

nick49

carrera1999

haha - Mine is not a cabriolet but it is... ocean blue, Savannah, GT3 kit with Black 3 piece wheels

fast996

a rising rate? fmu eh? not sure how much u can boost w\ stock dme timing -

carrera1999

Sorry I added to the specs. I was planning on starting with a 3lb spring and go from there. Or did you mean that common turbo tuning backs off timing in boost? IT will be intercooled. If I get 30-50 hp I would be happy. I have already bought some forged rods and pistons and am ready for a crisis rebuild. I just want to get the kit mocked up before the engine gets the rebuild.

chsu74

People have had success with a supercharger. More linear power delivery that is usable BTW. GL with your build.

Barn996

Nice Avatar Chao...finally.

Capt. Obvious

Good lord, this isn't a Civic and it's not 1999. Please don't just slap a rising rate FPR on the car and think you're tuning it. If you've been around turbo cars as long as you say you have you know what a terrible, horrible, no good, very bad idea this is. At the very least (and it's still not a great way to do it), get some kind of MAF piggyback like a Super AFC or something.

Also, an A/F gauge is not a good way to tune. Get a proper wideband O2 and pyrometer at the very least.

Even better, invest the money for Durametric and learn how to log properly and educate yourself on tuning a modern car the right way. There are many, many good resources out there for Motronic tuning, particularly www.nefmoto.com.

Macster

Dare I say if you attempt this you will add one more to the 'fail' tally?

Maybe I'm being unfair.

Ok, let me see if I can offer something in the way of help.

The EGT gage is just a gage. The EGT must be within design limits at all times or the gage will just indicate after the damage is done the EGT got too high.

Ditto the A/F gage. It is just a gage. You can't monitor or tune the engine's A/F in real time. The A/F mixture must be right at all times or as with the EGT by the time you are informed the A/F is not right well, the info comes too late.

For the boost gage's pick up point: For an idea of where is the best place you can look at where Porsche locates the Turbo's boost gage's sensor or where aftermarket turbo kits locate the boost gage's sensor.

Where to go for the Turbo oil feed line? The oil pressure connection is for pressure measurement. It is not designed (afaik) to flow much oil. For a good place, for an idea of a good place, I'd at least use the 996 Turbo as a reference in this area too.

I'm not aware the 996 Turbo has any oil scavage pumps at the turbos. The Turbo engine like all Porsche engines have scavage pumps in the heads (under the camshaft covers), to remove oil from under the camshaft covers along with a scavage pump in the crankcase. (Dry sump oil system.)

The oil is removed from the turbos via the pressure of the oil being fed to the turbos. Each turbo has an oil collector box into which the oil line from the Turbo runs. As an aside: These collectors are supposed to be drained at oil changes, though many do not do this. I asked what the drains are for since just a tiny volume (relatively speaking) of oil comes out and one tech suggested it is that some oil comes out and that the volume from each collector is the same.

As a starting point for where the turbo oil from your setup should be routed, I refer you to the 996 turbos. I do not know where the oil from the turbos goes after it leaves the turbos. I've never looked into this that closely.

This might be as good time as any: I hate to sound like a broken record on this subject, but with the 996 Turbo you have a pretty good example of a very good turbo charged modern Porsche engine.

There are two types of fuel delivery/supply systems: Return and returnless (on demand). Returnless/on demand is used more and more frequently because this cuts down on hot fuel being routed back to the tank which raises the fuel temp which increased vapor emissions and so on.

I'm sorry to say I do not know off hand what type the Turbo uses. (My 02 Boxster uses a returnless fuel system).

The Turbo does have a fuel cooler (courtesy of the A/C system). Also, the Turbo's fueling system is a bit goofy in that the fuel tank has two basins that straddle the cardon shaft/front diff.

Fuel siphon jets are used to feed fuel from these basins to the pump. Once fuel falls below the half way point this is the only way fuel can be removed from the basins. (When this system fails (though rarely) the car runs out of gas at half a tank of gas. While the basins are still full of fuel the siphoning system no longer pulls the fuel out and directs it to the pump.)

Anyhow, this fuel siphoning system which requires the fuel pump to pump a lot of fuel over and over again can heat the fuel so the fuel cooler may be for this reason.

BTW, the Turbo DME relies up wideband O2 sensors for more precise fueling of the engine.

You haven't even asked about the use of intake coolers (intercoolers) which I have to point out are built in the Turbo's body. (The routing of these -- I have pics of a Turbo with its engine out somewhere -- is a work of mechanical art.)

The intercoolers remove quite a bit of heat from the incoming compressed air which improves combustion chamber filling and reduces the engine's chances of suffering from the early signs of detonation. The knock sensors of course would detect this and signal the DME which would dial back timing but this costs power and diminishes the benefit of the turbo-charging.

I do not know how to say this other than this way: Unless you really like reinventing the wheel and spending a lot of money and spending a lot of time doing this, my advice would be to buy an off the shelf turbo charging system or buy a Turbo.

Sincerely,

Macster.

carrera1999

Wideband o2 from Innovate ...That is what I meant sorry for the confusion.

I attempted to tune my 92 Talon TSI with DSM Link and was not very good at it but that was with a huge turbo and 20 psi. We are talking about 3-5psi of boost with this project even the stock ECU should somewhat adapt to that - I am just talking about a little extra fuel.

I understand what you are saying though probably not the area to go cheap


But....The Kleemann supercharger kit on my CLK55 uses a rising rate regulator and no ecu tuning

carrera1999

Good Info thank you!- most of this I know and there are ways around all of those problems

I have worked with both types of fuel systems - and I found some Exploded views of the 996t and GT2 systems. Thanks!

http://www.autoatlanta.com/porsche-p..._911_parts.php

chsu74

Macster

Well, you have a good attitude. If anyone can do this on his own and do a good job I think you can. Best of luck.

Sincerely,

Macster.

SSST

I'm not going to be a naysayer because I don't know enough to be a naysayer. It sounds like an interesting project and you understand the risks. Good luck and I hope you will post your progress and results.

chsu74

You may want to follow this thread. Same engine.

https://rennlist.com/forums/porsche-...o-project.html