Replacing my Turbo, but with which one ?

I have an 1986 911 Turbo, with a turbo on its last legs !!!! to replace it, is a damn good excuse to upgrade it !! But what with the K27, or the K29, but I've told they still are "old technology" But I've been reading up on a Garrett Hybrid Turbocharger, has anyone got one / uses one.
Also is it recommened that I upgrade the intercooler, and / or the wastgate.
Thanks Guys, Paul

Paul-

We seem to be on the same track, although I'm a bit ahead of you, time-wise. I switched to a AirResearch TS04 turbo, but I'm not sure you would need something that big, since it would depend on what sort of horsepower the rest of your car was set-up for. I'm not sure what the relationship is between Garrett and AirResearch, although there is one. My wrench suggested that AirResearch turbos were built to slightly better specs, and they were a bit more money. Also, after much deliberation I decided not to go with a ball-bearing version of the turbo, the "modern" technology, because the AirResearch guy said that they hadn't been able to demonstrate benefits (like longer life, faster spool-up, etc.) on my application with a ball-bearing turbo.

As for an intercooler, I put on a 1100 cubic incher from Motorsport Design in Scottsdale, which is the absolute biggest that could fit on my car with the stock rear deck. I'm not sure you could go that big either, since I have a Carerra intake manifold and associated stuff, which allows for a little more room for an intercooler. Still, you could easily fit a 800 cubic incher there. A bigger intercooler, as others have pointed out, only makes sense if: you're making a LOT of power and using it and/or you track the car a lot.

The stock 930 wastegate is a good one. Rather than upgrade it, if you want to do anything you should put on an electronic valve controller from HKS or Greddy. Others on this board have had good experience with them, I think. (I have Motec engine management, with boost control, so I can't tell you about the valve controllers from personal experince on a Porsche).

Good luck. Fun stuff, isn't it?

Bruce, I have approx 307 at the back wheels, I have a sports clutch fitted, ss headers, ss exhaust, cam work, 1 bar boost spring and a K&N
So how does your AirResearch TS04 turbo compare to a K29 for instance, the guy I was talking to was obviously pro garrett!!!
It is a lot of fun, esp when the turbo kicks in, it just sucks before that, all the work I've had done has reduced the lag, but its just not enough !!
This garrett guy was the one that said about locking up the Distributer, I've never heard of it but he reconns he has been in the business for "25 Years"
What do I know I'm comming up for 4 years ownership, but really only started mods and racing about a year ago.
Alot of fun yes, just don't ask the bank manager !!!
I do appreciate all the advice Bruce, just can't get enough !!

/Paul

O.K., Paul. How serious are you about reducing "lag"? If you've got the dough, try this: machine the head to fit Niresist rings, go to Mahle 8.0/1 pistons. Then, get rid of that godawful CIS fuel system, which ws pretty good for the late seventies, but by the mid-eighties (let alone 1994, on the 3.6 Turbos!) should never have been on Porsche's signature car, and go to engine management control (fuel, spark and boost) (Electromotive, as long as your cams aren't too radical, or EFI; Motec or Zytec if you can afford it).

Result: off boost driving is great, with throttle response just fine, unlike the stock cars, or stock cars with your kinds of mods. On boost driving is unbelievable. Here are some numbers for ya:

616 crank horsepower and 564 ft lbs torque at 1.05 bar. 12.04 quarter at 125 mph at .8 bar starting from dead idle (haven't tried it dropping the clutch or at 1.0 bar, but the car's a solid elevens vehicle).

I could go on, but if you want to know more you should contact me off list. This isn't just a Turbo board.

If you don't do all that, I'd go to a T03/T04 hybrid. I think those flow enough for 500 horsepower. Don't know the capacity of the K-29s.

Hey guys you are getting me excited here. I am planning on headers and muffler change along with a HKS in the near term. The thing I noticed missing was bigger slugs. I think no matter what, the old " no replacement for displacement" axiom applies.
I am starting to set aside some bucks for the big do-over in a year or two. Any experience with Power Haus's work? thanks this is some fun stuff. david 89 turbo cab

P.S Bruce Keep the turbo stuff comming!

I have an '83 turbo that I brought to Powerhaus to have some upgrades. Very bad experience, dents in my hood, he kept the car a month before he started working on it and put over 100 miles on it. I could go on but I think the people doing the work for him are very good but the prices are extremely high compared to others.

BTW, I have a K27 hybrid that spools quick, full boost at 3krpm. I also have the B&B exhaust, kokeln intercooler and cams. It puts 350hp on the rear wheels @0.9bar.

Chuck
P.S. I'm using Don Jackson in Phoenix now, very reasonable and they do all the upgrades, just no advertising.

Here is the key with Powerhaus: you must agree with them as to when the work will be done, and then you must agree with them how much they will pay you back, or what else they will do to your car for free (or at least cost) if they don't meet the deadline; week by week, they pay you more or do more if they keep missing the deadline. The work they do, now that Bob Holcombe is doing it for them, is superb, but you need to keep the heat on. I know.

As for bigger slugs, good idea. I went with a 98mm bore, and used a 993 crank, which has a 76.4 mm stroke. Displacement becomes 3.5. Low-end grunt, especially with 8.0/1 cylinders, is significantly improved. It's the first engine they've done this way, I believe, and they've told me they'll recommend it again. I only got there because my stock crank had been turned too much, though. Splitting the crank case is expensive.

Again, check around. Holcombe is one of the best in the world. But you gotta be on him like white on rice to get things done timely, becasue he has a LOT of regular, big bucks customers whom he favors over schlubs (like me, for instance).

This isn't just a Turbo board.

I disagree...I pretty much enjoy reading about Turbo exploits and adventures and numbers, even if I don't have one. Preach on!

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Mark Szabo
1986 911 Targa 3.2

Interesting and am I intrigued as a d.i.y. guy. This bit about the engine management systems has me going because my problem will be getting an epa test passed by a commercial importer. If I can set my 85 930 up with this system so that it would run super clean with a cat, then the c i could run the standard test and certify the epa. That would get me a great running machine and the bulk of the money would go for good hardware that won't choke the thing up. which of these systems would work for a super clean runner and still allow for way out mods later on? How much is all this hard ware, Bruce? (P.S. the reason that I think this might work is that Porsche did not have an equivalent 85 US model!

Well, I described a lot of hardware, but I think what you're looking for is the engine management stuff. Some things to keep in mind:

Dunno where you live, but in any event I think to get the your Euro certified, you will have to show original smog equipment on your car. I do NOT know much about this (although my car is a Euro, the certification was done before me), but I'm not sure how much tweaking you can do with a stock car and still get it over here legally. Once you do get it here, things get easier, but how much easier depends on the state. In Calfornia, there is a visual inspection, as I recall, and some inspectors don't seem to care what it looks like if it sniffs o.k., and some do. There is no visual up here in Washington. The point is that going to an engine management system is going to require changes to the engine compartment that could be picked up, either by the feds or a nosy state inspector.

That said, here's what I know about engine managment systems and their prices. The low end is Electromotive. About $3750, plus installation. Problems: sensitive to cams with significant overlap over stock--that messes with idle control. Idle is a ***** with these things no matter your cam, and the problem is that idle is an important factor with smog tests. In Washington, you can't just drive up to a smog station and have the car pulsing between 900 and 1200 rpm as you get smogged. You'll be flunked, no matter what the sniffer says. Plus, it just pisses youoff too much. Electromotive is well priced, but I would never go with it unless or until I met a wrench who had successfully installed it ON A 930.

I've heard that EFI is the next step up, but don't know anything about it, including its price.

The next step up is Motec. This is what I have. A 32-bit processor, lots of programmability, way more sensors than the lower-priced units, decent idle control, boost control (check out their website, which I don't have right now but I think I found with a search on Yahoo). Used by lots of Porsches at Le Mans. Disadvantage is price, and geekiness needed to program the thing effectively. I got mine done for $8750, but that was because I had patiently waited for Powerhaus/Motorsport Design to install the Electromotive system right, and they couldn't get it to where any of us were satisfied. Full cost installed by someone who knows what he is doing is probably just above $10,000.

The most expensive, and some say best, system is Zytec. Amazing control and monitoring of engine parameters. Disadvantages: probably over $12,000 installed, and the only person in the U.S. who knows how to do this sytem right that I am aware of is Bob Holcombe in Scottsdale. Motec people who know what they are doing are more common.

So there you have it. You get what you pay for, I'm afraid.