pig4bill

I've seen a lot of ads for various bolt-on performance mods like turbos, chips, fuel injectors, MAF, exhaust, etc. They all promise a certain hp gain. I know if you put them all on the gain is not cumulative. Even so, it seems like 100 hp gain is not hard to achieve. Maybe even 150 hp. Is this so? Do any other changes have to be made, such as internal engine changes? Can the driveline stand it? I sure seems like an economical way to go versus hunting up a 3.6 Turbo.

Erik

getting about 350-400hp seems to be within reach with just bolt ons. By just changing your exhaust to a more efficient one, and changing the boost to 1 bar and changing the turbo charger, you should be on your way. (and put a more efficient intercooler on the car). Of course the higher you set the boost, the shorter the engine will eventually last. If you want more then the above HP, you will start to spend some real money, 3.4 or 3.5 cylinders, different cams, etc etc

ZCAT3

Hi pig4bill -

In my search for a 930 I have test driven several 86s and 87s with various performance modifications. The 87 I almost bought was straight stock and felt good (better than another 87 stock car I compared it to). I later drove an 86 Euro 930 with a recently installed K27 turbo charger, and that definitely had some more boost than the 87 (I believe the stock U.S. cars came with a K26 turbo and a bit less HP than the Euro version). Yesterday I had the pleasure of driving an 86 with a Powerhaus intercooler, a borla dual tip exhaust, and a powerflow intake system - the turbo appeared to be the stock turbo. This car was by far the most responsive 930 I have driven - and it sounded great as well. With the K27 on this car it would be awesome. Now I have no idea what this does to the longenvity of the engine, but this car had 96K on it and felt very good with no leaking or other obvious issues.

pig4bill

Zcat, thanks for the info. I see that 87 is still for sale, maybe patience will pay off for you.

From what I see on the net, the K27 is yesterday's tech. Could be just sales flack, but the newer stuff from Garrett looks appealing and cheaper to boot.

ZCAT3

Hi pig4bill -

I was talking to Steve Weiner at Rennsport about this and he said the K27 is the best turbo for the 930 as it is the most up to date turbo that can be merely bolted on without any modification. He also suggested that the best upgrade for the 930 (in the bang for buck category) is to upgrade the headers/exhaust system using the B&B system (I think the parts alone run over 3K). I have had other 930 experts tell me the same thing. This supposedly makes the car much more responsive at low RPMs and gets the turbo to kick in at the low to mid 2000 RPM range. I don't really care about more HP if it is simply at the top end - the car can already go faster than I will drive it. But better low end response would be great. I am debating doing this (if my wife doesn't kill me).

pig4bill

Zcat, yes, he's told me similar things. There seems to be 2 schools of thought on 930's: the first being the one Steve's in, advocating tried and true components like the K27. The other being upstarts like Powerhaus that say various Garrett and other turbos are superior to the K27. To complicate things further, we have to deal with passing emissions.

Bob 87 930

I have an 87 930 and have added the parts incrementally so I have a good feel for what has added fun to the car. First did the B&B twin outlet muffler nice sound slightly better spool up. Next did the Powerhouse K&N intake, very cool "wind sucking sound in the back seat on boost, little noticable performance gain. Then bit the bullet lost all the restrictive exhaust parts and did B&B header and K27 hybrid turbo KKK body bigger impellers Awesome and I mean killer sound and much added power boost was now coming on at 25-2800 vs 3500. Be aware at least on my car now with this header muffler combination that when the engine is hot and you are pulling boost for several seconds like the 3rd gear run from 80 to 120 and then quickly lift you will shoot fire out the exhaust tips about 3 to 4 feet. Very cool affect and definately would deter tailgaters if they could keep up but something to know beforehand. My mechanic told me this would happen before we did the work but the first time I saw the flames coming up the rear wing it was quite shocking.

I Just did the WebCam SC sport cams and start to build boost a bit earlier around 2000 rpm but all in all the car is even less responsive than with the stock cams. Trying to figure it out and may have to play with the cam timing a bit but we think we have them set to maximize the low end.

So the best bang for the buck is the header muffler combo. FYI, I have been told the 930s or the 911 family in general will pass emmisions and mine has (on a dyno as required here) in this bolt-on plus cams modified form.

Good Luck, I will repost once we have sorted the cam thing out. We are going to pull the cams to make sure we did not get a 964 grind in error which would take away from the bottom end as I am experiencing.

Have fun my wife has threated to kill me each time the bill comes in for the "little repairs on that damned red car but I always go back for more.

Bob
red87930

pig4bill

If I may be so rude as to ask, how much did that header/turbo setup set you back? I assume you lost your heater in the process.

ZCAT3

pig4bill -

I am having my headers replaced next week and already have the K27 turbo in the car that Steve Weiner so often advocates as the best turbo for the 930. I am also having a light weight clutch assembly installed and an Andial 1 bar adjustable waste gate. I will let you know how this affects performance. As for cost, the turbo was put in the car about 1 year ago by the prior owner at a cost of about 1K for parts and several hundred dollars labor (he may have received a credit for the old turbo).

The changes I am making next week should be around 2K for the headers and heat exchangers, around 1K for the new clutch parts (the car is ready for a new clutch anyway), a few hundred dollars for the waste gate, and labor to be determined (the expect 1.5 to 2 full days of work for this).

At the completion of the project, the car will be basically in line with the PowerHaus stage 1 930 bolt on upgrade they have on their website (less the larger intercooler as I am sticking with the stock version for now but adding the lightweight clutch that they do not add until their stage 2 upgrade). According to PowerHaus, this would put the car over 400 HP. By the way, I spoke to PowerHaus about their stage 1 kit, and the cost for that kit is 6K for parts.

As for CA emissions, you have 2 choices, change the muffler back to stock every time you need to pass smog (as the 930 Cat is attached to the muffler pipe coming out of the turbo), or leave the stock muffler in place and just change the headers. I am told by GHL Headers that they are currently designing a cat attached for their muffler/header system for CA cars. They expect to have this ready soon.

I hope this is useful -

Bob 87 930

Asking pricing is not rude at all in the p-car family. The B&B header was about 1900 with heater boxes so I still have hot hot heat and the B&B muffler was a grand. Excellent purchase from my perspective.

Just as a side note for those that like cool sounds cut the muffler off the wastegate. Just make sure you cut it so it has a nice downward flow and besure you adjust the scavenge pump oil return line to be out of line with the fire that will come out when the wastegate dumps but it does add a n interesting sound when you overboost.

Bob 87930

pete77930

I have a 77' 930 that is undergoing a complete rebuild, 3.2 p/c's, balanced crank, etc. my questions are
1)looking at ghl exhaust, is it a good product, what exhaust has the best sounds?

2)I've heard that the k-28 turbo is the new hot ticket, is this true?

3) Whats the best intercooler avalable, and can a fullbay intercooler be custom made to fit under the lid with the a/c condenser and by who?
P.S. can you make the car shoot flames at a light sitting still?
Thankyou,
Pete

pig4bill

Thanks, all, for the responses. Zcat, I'll be watching your project with particular interest because you're local and doing many of the things I'd eventually want to do. At 400 hp it seems you'd be on the threshold of where Steve says you need twin-plugging, etc ($$$$$).

Bob 87 930

Pete,

I can not shoot flames when sitting still.
I can only do it after being on boost.

Bob

ZCAT3

Hey pig4bill -

The car is in the shop and will be ready next week. I actually have spoken to Steve W about all of this and my general impression is that the only modification he would not make is the 1 bar spring. He did say that if we did set it at 1 bar, then a bigger intercooler should be added. We are going to stay with the stock intercooler for now. If the car runs hot under boost, then we will upgrade as we do not want to hurt engine life.

Michele

Pig4bill -
It's a sad state of affairs when a wife has to learn from a chat room that their 930 is having the headers replaced when she thought it was just going in for a clutch replacement! As the more frequent driver of this car - I'll also let you know what I think about its new performance...if we ever get it back from the mechanic.

Be very afraid, ZCAT3.