Jon B.

Just looking around for suggestions and I know it's probably different from car to car. But, what are the good rules of thumb for the pre-installation maintenance of the Murf kits?

I'm looking at having my car gone through prior to my redeployment (military), and want to make sure that everything that isn't up to snuff is remedied. So I've started compiling a list, and will add whatever is recommended here to it.

My car is an early '86 5-speed. TB/WP was less than two years ~15k miles MAYBE. Cam timing was checked, and set properly at the same time. It has the S4 regulator, and honestly runs very strong with Porken chips. I was chasing a warm/hot stalling issue which will be fixed 100% prior to installation. I'm planning on changing all fluids, etc with this service as well. The MAF was recently rebuilt also. All rubber fuel lines, as well as dampers/regulators have been replaced. I think that it MAY need a new fuel pump sooner rather than later. Not sure if that comes in one of the kits. I know that injectors do. I was tracking the 044 pump as being used regularly?

What am I not thinking of? Also, regardless of how recent certain things are on the car, they will be checked out again. I'm planning on Stage one.

Shane

I replaced all the sensors, had the intake resealed, vacuum lines, a/c etc, I wanted things running 100% stock, to prevent any down time on the Murf install fixing other issues. It worked well. The 044 pump and the S4 reg should have been done along with the install but time was a factor so I delayed (for too long). At stage one your head gasket won't (shouldn't) be an issue, it wouldn't have been an issue for me as well cept for delaying the pump and pressure bump on the fuel side of things.

AO

Shane pretty much covered it. The only thing I would add would be to make sure the clutch is up to the task. The 86 is a dual disk and can handle things better than the 87+ single disk, but just be ready to pop for an upgraded clutch and resurfacing of the flywheel.

Jon B.

Shane & Andrew,

Thanks for the replies, I really appreciate it. I knew I needed to check/replace the vaccum lines, I'll add the Intake as well. I'm thinking I should just do a complete refresh at the same time. I have a receipt for almost $20k on a top-end rebuild from TBF at some point in the car's past. I need to itemize what exactly they replaced/touched. Stan had the car after the fact, and he's pretty thorough also.

I was planning on checking the clutch system as well. I hope that it doesn't need too much attention.

AO

What stage are you thinking about? Stage 1 should be fine with your stock clutch. Stage 3... ummm not so much.

Shane

Yup stage 1 won't stress the dual disk much. Primary is to solve any issue before adding boost as it has a way of magnifying problems.

When Tim was fitting the kit to my car they dynoed it at Stage 1 and with an auto it put down 370hp/333tq at the wheels. So with a 5sp you should be closer to 400rwhp.

http://www.erik27.com/shane/Rennlist%20post/dyno.jpg

Jon B.

Andrew, I'm planning on just doing the Stage 1 for the time being. I'll upgrade to "big boy" status after I put money into the interior of the car. Either that, or paint...

Shane, I looked through your thread when looking for S3 info, and I noted the Stage 1 results like you posted. I was thinking around 400rwhp as well. My car has an X-pipe, and different exhaust after the X as well. So, I shouldn't run into the "issue" you had without a RMB, or something similar.

What dual-disk options are there for clutch upgrades? Or would I need to go single for an upgrade?

Also, I posted this on the Murf forum, and got these recommendations from Z for those interested;

- 044 fuel pump with Murf Strainer. Makes installation much easier for the larger pump.

- Fuel Filter

- Plugs (one to two heat ranges cooler) Not platinum, thinking NGK?

- Low temp thermostat combined with Water Wetter, and a good old fashioned cleaning of all the debris between the radiator and AC condenser

I should also note for those following this that any question I've posted on the Murf928 website forum is answered in about a 12 hour time-frame. Z has answered all of my questions with plenty of information and if the ownership experience is anything like that, I'm sure that I'm not going to be disappointed at all.

dprantl

I run BCPR7ES NGK plugs in my non-murf supercharged 928. These are 2 heat ranges colder than stock and the car runs very well with them.

Dan
'91 928GT S/C 475hp/460lb.ft

Shane

Our dual disk clutches are the upgrade for the S4/GT guys, for us to upgrade we would need to go to the performance clutches like what Carl sells at 928 motorsports.

The NGK are good plugs and are what I ran in my twinscrew.

All of Zs' recommendations are

Mrmerlin

Jon if you didnt see it there is a cutout on the bellhousing to adjust the I plate H tabs.
This idea was taken from some other poster that was having issues adjusting the clutch. With one you have simply removing the cover and having someone press the clutch pedal down will show what is going on with the release.
Otherwise if your not having any issues you can leave things the way they are.

FWIW I never did have any clutch issues with the car nor did i have to adjust the I plate,
but thought I would mod the cover just in case.
Since there were so many other issues that had to be fixed
You also might consider getting a used bell cover if you dont want the modded part or use it as a swap out /testing part

Jon B.

Dan & Shane, glad to hear that you guys are running what I was thinking. Looks like I'll continue that direction. I figured that upgrading the dual to something else would be aftermarket, I'll tackle that once I go with the Stage 3.

Stan, I had been down there was curious about it, but since it came from you that way I figured it must have been for a reason! So, thanks for that clarification. I don't (didn't) have any issues with the clutch/gearbox as far as I can tell. But, like everything else, it's getting a good once-over.

I've been debating going with headers for the setup as well, but I think I'm just going to replace everything south of the X pipe with new piping and Borla XR-1 mufflers. That'll about take care of everything I think. The car has newish rubber on it and I'm doing the brakes up to S4+ spec at the same time.

dprantl

A stock DD clutch in good condition will hold up to 420rwhp or so. Mine has been doing this for years now. There is also the option of going with a pressure plate that has 50% more clamping force with the rest of the components stock.

Dan
'91 928GT S/C 475hp/460lb.ft

Jon B.

Dan, is that some sort of "hybrid" setup? Any more info would be appreciated!

dprantl

No, it's just all stock DD components but the pressure plate is modified to be stronger. Mark Anderson was able to source this modified pressure plate in the past.

As an aside, I was told by several people that ~420rwhp would overpower my stock DD clutch, so I actually bought the modified pressure plate. It has been sitting in the garage now for a couple of years as it has not been needed. I'm sure I will need it soon when I put down 500rwhp though

Dan
'91 928GT S/C 475hp/460lb.ft

Jon B.

Dan,

How long have you been running the DD setup at 475? I'm pretty sure that the strength of the stock DD setup is underrated, like you and others have stated.

So long as it's shown to be in good order, I'm not going to worry about the upgrade until Stage 3 numbers similar to what you'll likely be putting down.