I will keep this post locked, until I can get a good amount of information in first, then I will unlock it for comments and additions.

Keeping along the theme of the 944 hp post, it was requested that I write up something for the 951 crowd. Again, this is a basic guide to getting more out of your 944 turbo. This does NOT include 944 NAs, that want to turbo their engine.....see the 944 post about that.

I will also try and keep this post unbiased. There are companies that I do not like to deal with, but none the less still have good products, and I do not want my personal feelings to downplay the quality of their product.

And pardon my punctuation, I do not use apostrophes in this post, because whenever I edit the post, it adds about 2 extra apostrophes to everyone i have used, which looks really odd. Glitch in the forum software.

Again, this is based on my years of modifications and racing in the Porsche world. Take it for what it is worth (free), it is designed to give a general idea of what is out there for the cars.

Best Bang For Your Buck Modifications:

Chips and a boost controller:
Cost: $350 for the chips, $100 for a manual boost controller, and anywhere from $300-600 for an electronic boost controller
Top Vendors: Vitesse Racing, Max951 (Russell Berry and Lindsey Racing), Weltmeister, Autothority
Gains: 35-40hp
Chips that remap the DME unit, and allow for increase boost (by properly adjusting the time, adding fuel, etc) are probably the best bang for your buck modification out there. I have used and tested almost every vendors chip set at one point in time, and some give better results than others, but all offer signification improvement. You must install a boost controller when changing chips, and delete the cycling valve (stock way of keeping bost in the 10psi range). Aftermarket chips typically run about 14-15psi boost, which is still very safe on the engine and components. Personally, I think Vitesse has some of the best chips on the market, and he is always willing to help if you have problems, but again, there are other options out there as well. I will talk about the differences in boost controllers later.......

Exhaust (test/cat pipe, and catback section):
Cost: $300-$1800+
Top Vendors: Fabspeed, Speed Force Racing, Lindsey Racing, Bursch.
Gains: 20-25hp
There are multiple parts to the 944 turbo exhaust (in order of flow): Headers, Crossover pipe, Downpipe, Test/Cat pipe, Catback with muffler. I will eventually try and hit them all, but starting with the basics.
Best bang for your buck out of a 944 turbo, is to get rid of the catalytic converter. Some states emissions will prevent this, but if you can pitch it, get it out of there. Getting rid of the cat will free up about 20hp on a stock 2.5" exhaust. It can be replaced cheaply with a bursch test pipe for $300, or you can upgrade to a 3" full exhaust (test pipe and catback) for more money. Like I said though, most of the hp gain will be the deletion of the cat. My dyno tests have shown that a 3" exhaust over a 2.5" catless exhaust shows gains of about 4hp and 7tq, making the total gains around 25hp over stock. If your exhaust system is starting to fall apart, then my all means, go with the 3" full system, get the maximum power, and a little less weight. The stock muffler is a straight through design, so any changes to the muffler alone, will only result in change in tone, and not gains in hp. If you must pass emmisions, then there is always the option of going with a 3" exhaust and a high flow cat.

 

Other Modification:

Turbo Upgrades:
Cost: $1200-2000
Gains: 30-40hp and up
Vendors: Vitesse Racing, Lindsey Racing, Speed Force Racing, Kokeln, etc
The 944 turbo came in 2 variations, the K26/6 turbo and on the S, the larger K26/8 turbo. The differences between the two turbos was the size of the exhaust housing and impeller. There are many aftermarket turbos that you can put on the cars. Vitesse makes kits from Stage II, through Stage IV. The other vendors have similar kits with their own custom turbos. Upgrading the turbo is something you should talk about with the vendor you choose. There are many things to consider when upgrading the turbo, for instance, that larger turbo you put on the car, the larger potential for hp gains, but also the more lag the turbo is going to produce. IE, your powerband might not come in until the mid to upper RPM range, so you need to decide how you are using the car. Some kits are designed to come in sooner, with a longer even powerband, others are designed to come in later, and hit harder to redline.

When you upgrade the turbo, you are taking a big step, as other items need to be upgraded as well, in order to keep the engine safe. Some of those items are: Different tuning (chips), larger injectors, different air intake system, etc. I usually tell people that from a stock car, a turbo upgrade done properly will run anywhere from $3000-4000 with all the components.

Mass Air Flow (MAF):
Cost: $1000-1200
Gains: 20hp+
Vendors: Vitesse Racing, Lindsey Racing, Speed Force Racing, Promax Motorsports
I would consider upgrading the MAF as the next upgrade after exhaust upgrades. Keep in mind though, that if you are planning on doing a MAF, then you don't want to purchase chips for the car, as chips will usually come with the MAF kit, and will be different from chips designed to be used with a stock AFM. A mass air flow will greatly improve the driveability of the car (throttle response specifically), but will also allow for more air flow to the engine, meaning more hp. If you are upgrading the turbo to anything larger, then I would highly recommend you add a MAF to the system as well, to allow the turbo to get as much air as possible. The other advantage of a MAF, is that it cleans up the engine bay, and gives you easier access to the front of the engine.

Manual (MBC) versus Electronic Boost Controller (EBC):
Cost; $100-600
Gains: Controls the boost with aftermarket chips
Vendors: HKS, Apexi, Greddy, etc.
I talked about the 2 a little earlier, but here are some simple differences: The cheapest controller is obviously a manual boost controller. You simply install it inline with the wastegate, and will will control the boost pressure based on a preset level (by turning a ****). It is a simple ball and spring mechanism. The advantage is that it is cheap and easy to use. The disadvantage is that it is temperature dependent. IE, if you set the boost on a 95 degree day at 14psi, that is where it will run when it is 95 degrees out. If the temperature drops to say 60 degrees, you might be running 16+psi, which means you have to sit there and adjust the controller. An EBC on the other hand is a little more difficult to set up, but once it is set, you don't have to worry about temperature changes. There are also a lot more options with an EBC, such as scramble settings, where at the touch of a button you can have another boost level set. There are also many other options to EBC's, but I'll let you guys research and read more about those....

 

Saving for space.

 

There is a guy named Joe from german dismantlers who claims he has been building and racing 944s for 25 plus years and stated to me that the 89 944 turbo s already has a chip mod and to leave the cat because you do not see an increase in hp until after 6000rpm and it is not a substantial increase. Does Joe stand any ground? I dont want to waste time and money. Help me Doc!
thanx

 

I don't know where your guy is getting information, but is is common knowledge among 944T owners that removing the cat will increase your hp significantly through the RPM range.

Stock cats have a pressure drop of 2.5-5 psig depending upon how plugged they are. Any pressure drop you eliminate runs the turbo better and gives more hp.

The KLR chip in the 944TS allows pressure of 11.89 psig as opposed to the stock 944T 10.88 psig.

 

Wow, not sure how I missed this one. Maybe I was trying to purge GAD from my memory. I would do a lot of research before dealing with GAD. The 944TS does not have a chip mod....well it does over the standard non S turbo, but the stock boost of the TS is 11psi. If you turn up the boost, you need a different chip set to get enough fuel. I have dyno tested cat removal personally.....last I checked GAD doesn't have a dyno.

 

Could someone indicate what is the proper price for 100 000 milege driven 944 Turbo?

 

Can anybody give me a suggested mod list to hit 400+ hp? And estimated price to do so? Would I have to tear down the engine and install stronger pistons and such or would stock internals handle this?

 

Thanks for all the fun !!!

 

so obviously with larger turbo comes lag, but what if i want a slightly larger turbo? if i swap out my k26 for a k27 hybrid what kind of other modifications can i expect to need to do? I already have a maf from lindsey racing, intercooler upgrade, chip set electronic fuel control manual boost control. but i am running stock numbers to pass smog. i plan to tune it soon and have plans to upgrade fuel injectors since mine are stock but what pound injectors should be expecting to buy? btw my maf cost 500.00 so DAMN to 1200-2000$