Porsche 944 Track Basics

Got my hands on a "weathered" 1986 Porsche 944 NA and am looking to try to get it on the track this summer. The car will solely be used for travel to/from and on the track. Primary goals here are to make the car safe, budget friendly as possible, and serviceable to forge some good habits/driving skills. 

Right now we have a few basic projects we are trying to get done so we can attend our first tack day later this summer.

- Replacing the brake hardlines (there is a leak in one of the rear lines)

- Stainless flex lines

- Brake bleed

- Coolant flush / oil change

- Tightening up the shift linkage

We were also considering swapping the pads out for something more appropriate for track use. Any suggestions for good pads that would work for beginners? At present we are planning on keeping the stock calipers if they check out.

Any other suggestions, advise would also be welcome. 

You're on the right track with your list there, especially starting with the brakes. Definitely upgrade the pads, I've had good luck with the Hawk HP+ in the past and now use their street/race pads which I use on the street and haven't let me down on track. They use the same compound as the DTC-30 race pads but with street backing plates and chamfers, they work well cold but can also handle a lot of heat so as you get faster and use them harder they will keep up.

As you start to the push the car on track it will reveal any weaknesses the car has, make sure it is mechanically sound before you get there so you don't waste an entry fee with a broken car (looks like you have a good plan for that). I ran into cooling issues personally that I could not replicate on the street (at least safely) that showed up right away on track, in my case it was a low quality rad that the PO had installed that just couldn't pull heat out fast enough at high rpm and load so don't cheap out on the parts you are replacing. 

What track are you planning on running at for your first event?

Also, start a build thread and post some pics! (coming from the guy that doesn't have a build thread...yet)

Adam

Plan on rod bearings either now or later.  It’s a good time to do them if you have to do the clutch as you can yank the motor at the same time.  Otherwise, pull the crossmember after supporting the motor from above.

New motor mounts can help with vibrations/noise.

If your power steering leaks, fix it.  The pump and rack can be resealed through a couple of seal kits, the reservoir should be replaced and the main feed line.  Fill with ATF.

Check the oil cooler for any mixing of coolant/oil and replace the o-rings.

Only944.com has a great set of parts for the linkage, including the shift lever, support arm and linkage.  They have some other neat parts as well.

You can fill the transaxle mounts with 2-part pourable urethane from McMaster-Carr to improve shifting and reducing driveline “windup”

Look at sway bar mount braces to help reduce front sway bar flex that could potentially break the inner mounts.

Lots of urethane/Deleon bushings are available to replace worn out rubber.

Look/ask around with the Spec944 racers to see what they recommend for pads and mainentance.  There’s also a website with a decent information.

For day to day maintenance, http://Clarks-garage.com (RIP Clark) is still a great place to visit for service information and tips.

Do you know when the timing belts were last done? If you don't know or it was more than a couple years ago, that needs to be done before getting anywhere near a track. If the suspension is all original stock I'd guess the shocks have seen better days and I'd bet money that the bump stops are partially or fully disintegrated which can make for some interesting handling characteristics. Also don't be surprised if you can't tighten up the shift linkage much. That stuff, especially the shifter itself, is not the greatest design and just wears out and can only be fixed by replacing parts.

BrewCity20 said:

- Stainless flex lines

Having done this mod myself, I now recommend against it. The change in brake feel is miniscule and the packaging disadvantages, due to the much lower flexibility of a SS line and, if uncoated, its extreme abrasiveness to anything it might touch, are enormous. Instead I'd recommend just putting fresh rubber lines in. A trick to improve line feel is to add zip ties to the rubber line at regular intervals. A zip-tied rubber line gives about half the squishiness reduction of a SS line - which again, is very little.

For pads, I'll say +1 for Hawk Street/Race for a beginner, and when you have more experience I'd recommend moving up to EBC Yellowstuff which will withstand high temperatures better and might actually be nicer on the street, but are harder to control.

The firmness is a minor addition, the braided hoses helps prevent brake line failures on the track. 

For a street car, they aren't necessary and can make it hard to know when the hoses need to be replaced.

adam525i said:

You're on the right track with your list there, especially starting with the brakes. Definitely upgrade the pads, I've had good luck with the Hawk HP+ in the past and now use their street/race pads which I use on the street and haven't let me down on track. They use the same compound as the DTC-30 race pads but with street backing plates and chamfers, they work well cold but can also handle a lot of heat so as you get faster and use them harder they will keep up.

As you start to the push the car on track it will reveal any weaknesses the car has, make sure it is mechanically sound before you get there so you don't waste an entry fee with a broken car (looks like you have a good plan for that). I ran into cooling issues personally that I could not replicate on the street (at least safely) that showed up right away on track, in my case it was a low quality rad that the PO had installed that just couldn't pull heat out fast enough at high rpm and load so don't cheap out on the parts you are replacing. 

What track are you planning on running at for your first event?

Also, start a build thread and post some pics! (coming from the guy that doesn't have a build thread...yet)

Adam

Thanks for the info. Seems like HP+ is the way to go. I suspect a set is in my future.

Depending on how long it takes to get the car in running order, I believe Milwaukee Mile or Road America will likely be our first go. Assuming we can limit the number of gremlins we need to address.

I will!

In reply to dps214 :

The timing belt was done about a year before we bought the car (which subsequently sat for that year in a barn) so I suspect it should be good (the old belt and pulleys actually came in the trunk).

Shocks are on our "tier 2" list for now. I'm hoping to get through this summer season without too much capital investment and am putting those off. I guess we will see how the car handles at speed to see if that was a dumb strategy. They are toward the top of the list for a winter project though.

I've looked into the Only944 kit for the rear linkage and may swap that out if I can't improve the shifting through tinkering. Right now I have an issue where the shifter is nice and smooth front to back (e.g., between 1st and 2nd or between 3rd and 4th) but is really sticky side to side. I suspect the plastic bushing on the transaxle is corroded. Will have more info on that this weekend when I pull it off. If anybody has run into this issue before advice would be much appreciated. 

In reply to Stefan :

Thanks, some great stuff here.

This actually touches on one other issue we currently have. The previous owner pulled out the power steering pump to convert to manual steering for racing (not happy that he did). My inclination was to leave it for our first go and just run it as a manual). Is this a mistake? I have the old pump and can likely do a rebuild if necessary. The power steering rack is still in the car.

I also think the PO wasn't smart to take it out, but I don't think trying it with manual steering is a terrible mistake. It's RWD, well-balanced and not too heavy, it shouldn't be too awful without power assist, at least in short stints.

Stefan said:

The firmness is a minor addition, the braided hoses helps prevent brake line failures on the track. 

For a street car, they aren't necessary and can make it hard to know when the hoses need to be replaced.

This. 

No idea why anyone would run uncoated lines......are there reputable companies that even sell them?

BrewCity20 said:

In reply to dps214 :

The timing belt was done about a year before we bought the car (which subsequently sat for that year in a barn) so I suspect it should be good (the old belt and pulleys actually came in the trunk).

Shocks are on our "tier 2" list for now. I'm hoping to get through this summer season without too much capital investment and am putting those off. I guess we will see how the car handles at speed to see if that was a dumb strategy. They are toward the top of the list for a winter project though.

I've looked into the Only944 kit for the rear linkage and may swap that out if I can't improve the shifting through tinkering. Right now I have an issue where the shifter is nice and smooth front to back (e.g., between 1st and 2nd or between 3rd and 4th) but is really sticky side to side. I suspect the plastic bushing on the transaxle is corroded. Will have more info on that this weekend when I pull it off. If anybody has run into this issue before advice would be much appreciated. 

Honestly, I'd still consider replacing the belts or at least pulling the covers off and inspecting everything. Maybe not much of a concern on a street car, but for the abuse you're going to put it through, it's cheap insurance and the belts are under-designed and really don't respond well to sitting for long periods. On that note, if it's been sitting that long be prepared to replace a lot of rubber parts, and don't be surprised to have to do the oil cooler seals that were mentioned at some point.

dps214 said:

BrewCity20 said:

In reply to dps214 :

The timing belt was done about a year before we bought the car (which subsequently sat for that year in a barn) so I suspect it should be good (the old belt and pulleys actually came in the trunk).

Shocks are on our "tier 2" list for now. I'm hoping to get through this summer season without too much capital investment and am putting those off. I guess we will see how the car handles at speed to see if that was a dumb strategy. They are toward the top of the list for a winter project though.

I've looked into the Only944 kit for the rear linkage and may swap that out if I can't improve the shifting through tinkering. Right now I have an issue where the shifter is nice and smooth front to back (e.g., between 1st and 2nd or between 3rd and 4th) but is really sticky side to side. I suspect the plastic bushing on the transaxle is corroded. Will have more info on that this weekend when I pull it off. If anybody has run into this issue before advice would be much appreciated. 

Honestly, I'd still consider replacing the belts or at least pulling the covers off and inspecting everything. Maybe not much of a concern on a street car, but for the abuse you're going to put it through, it's cheap insurance and the belts are under-designed and really don't respond well to sitting for long periods. On that note, if it's been sitting that long be prepared to replace a lot of rubber parts, and don't be surprised to have to do the oil cooler seals that were mentioned at some point.

Do you suggest re-doing the whole timing kit (e.g., pulleys and the like) or should just replacing the belt itself be sufficient?

Replace the fuel lines coming up to the rail on the engine, there are two of them.  They degrade over time and then break, burning your car to the ground.

z31maniac said:

Stefan said:

The firmness is a minor addition, the braided hoses helps prevent brake line failures on the track. 

For a street car, they aren't necessary and can make it hard to know when the hoses need to be replaced.

This. 

No idea why anyone would run uncoated lines......are there reputable companies that even sell them?

Braided SS lines are only more resilient against external physical damage and overpressure, which only happen due to installation mistakes or crashes. On the other hand when they're old and worn out, they suddenly blow out their internal linings and lose pressure without any kind of warning the driver or mechanic could pick up on, while a rubber line will usually have visible signs of aging/wear and increased pedal squish before it blows out. So I don't think the safety/reliability advantage is so solidly on the side of the braided SS lines.

It's only within the last decade that uncoated lines have become less common on the market, they used to be available from all the expensive brand names, but they're not so easy to find outside of sketchy ebay ricer kits these days.

BrewCity20 said:

In reply to Stefan :

Thanks, some great stuff here.

This actually touches on one other issue we currently have. The previous owner pulled out the power steering pump to convert to manual steering for racing (not happy that he did). My inclination was to leave it for our first go and just run it as a manual). Is this a mistake? I have the old pump and can likely do a rebuild if necessary. The power steering rack is still in the car.

That's akin to asking about the best religion. 

My take?  I prefer power steering and the stock parts don't provide too much boost and makes the car easier to drive. 

At speed, the lack of power steering may not make a noticeable difference until the suspension is heavily loaded.  I know there are people that prefer the stock rack sans power, but even my lighter 924 with the slower ratio manual rack seems a bit too heavy to me.  To each their own though.

There are posts online about converting to an electric power steering column for the 924 and 944, it uses a Chevy Cobalt/Saturn ION column.  Its a bit involved, but it could be a solution down the road if you want power steering without the potential leaking issues or complications of the engine bay.  Couple it with the stock speed sensor and you can have speed sensitive steering, or just an adjustment knob on the dash somewhere.

A buddy bought a 924S to convert to 944 Turbo power, but he had a lot of fun tossing it around at track days with old worn out suspension.  The cars are so balanced that as long as the drivetrain is in good shape, you can generally fling them around and have a ball.  Lots of improvements can be made, but generally new bushings, stiffer springs/dampers and decent tires make a huge difference.

BrewCity20 said:

Do you suggest re-doing the whole timing kit (e.g., pulleys and the like) or should just replacing the belt itself be sufficient?

Belt(s). I'm not sure how expensive the pulleys are, but it couldn't hurt if they're cheap. But if you pull it all apart it's pretty easy to tell if the pulleys are bad or not by spinning them.

Also, yes, definitely do the fuel lines too. Forgot about that.

Manual steering is fine if you properly depower the rack. Not sure how it behaves without that but if the lines are looped and not just plugged it's probably still fine temporarily.

Stefan said:

Plan on rod bearings either now or later.  It’s a good time to do them if you have to do the clutch as you can yank the motor at the same time.  Otherwise, pull the crossmember after supporting the motor from above.

New motor mounts can help with vibrations/noise.

If your power steering leaks, fix it.  The pump and rack can be resealed through a couple of seal kits, the reservoir should be replaced and the main feed line.  Fill with ATF.

Check the oil cooler for any mixing of coolant/oil and replace the o-rings.

Only944.com has a great set of parts for the linkage, including the shift lever, support arm and linkage.  They have some other neat parts as well.

You can fill the transaxle mounts with 2-part pourable urethane from McMaster-Carr to improve shifting and reducing driveline “windup”

Look at sway bar mount braces to help reduce front sway bar flex that could potentially break the inner mounts.

Lots of urethane/Deleon bushings are available to replace worn out rubber.

Look/ask around with the Spec944 racers to see what they recommend for pads and mainentance.  There’s also a website with a decent information.

For day to day maintenance, http://Clarks-garage.com (RIP Clark) is still a great place to visit for service information and tips.

Highly recommend the only944 linkage stuff, it made the entire shifter feel 1000x better. I think I have 75% of the stuff on only944.com lol. 

I did the transaxle bushings with urethane as well, which definitely got rid of the windup feel. I think I made a post about it on here someplace, if you look around. 

Make sure to do the timing and balance shaft belts and tensions them correctly. 

Carry a spare DME relay (or buy the solid-state one, which I just ordered). 

For new fuel lines, shoot an email to len.cummings (at) verizon.net. He makes them at a reasonable cost and is great to deal with regarding fit, style, attachment options, etc.  Don't forget to do the jumper line from the rail to the FPR. 

docwyte said:

Replace the fuel lines coming up to the rail on the engine, there are two of them.  They degrade over time and then break, burning your car to the ground.

Thanks. That will be a must-do. I'll place that on the list.

BTW, I don't know why, but many people pay way too much for fuel lines for these cars with fancy kits that require cutting tube, etc.  Not to say they won't or don't work, just that they seem overly complicated for a fairly simple situation.  If you wanted to reroute the hose away from the heat, that wouldn't be a bad idea in the long run that is a different conversation.

All you need is the proper length and diameter EFI-rated hose and the appropriate non-worm gear clamps.

Cut the old band clamps and hose off, verify the diameter, length and routing.  Reuse the fittings with the new clamps.  Done.

Plan on replacing the hose every few years as a preventative measure and keep spare on hand in case of damage.

The 944 uses fuel pressures similar to other Bosch-EFI equipped cars of the period.  This includes the Turbo-Dodges I used to have, but they run slightly higher base pressure and route the hose over the hot turbocharger/exhaust and only had fires if the hose was left to rot or was damaged, similar to the 944.  Many just used higher (EFI-rated) rated generic rubber hose and clamps.  Porsche over complicated things with their fittings and caused more issues than they solved.  The return hose wasn't even EFI-rated as it saw very low fuel pressures.

I used a similar method on my 924 Megasquirt EFI conversion and its worked a treat.

In reply to irish44j :

Is there any way to get the tension correct without buying special tool 9201? I can't imagine that all 944 owners spring for that thing given how expensive it is.

BrewCity20 said:

In reply to irish44j :

Is there any way to get the tension correct without buying special tool 9201? I can't imagine that all 944 owners spring for that thing given how expensive it is.

I"m sure Stefan can give you a better description, but it can be done by "twisting" the belt between two fingers on the longest "open" run. IIRC the timing belt should be able to twist 180 degrees with (strong) finger effort and the balance shaft belt is 90 degrees (but I may have that backwards, look it up).

You can also tell by the noise it makes. When too tight, you'll hear a "whine" from the cam tower and the balance shafts. So basically you get the whine and slightly loosen it until it goes away (when car is warm).

Totally unscientific, and yeah plenty of people who ahve never worked on these cars do it without the Cricket tool or the Porsche tool. Also make sure to orient the idler pulley correctly, as that can be a source of noise. It takes a good bit of fiddling around. 

Again, though, will defer to Stefan, who is an actual expert on these cars (whereas I'm just a guy who restored a 924S and has little long-term experience with them. 

I'm no expert, just someone who's done plenty of reading on the cars and hanging around people who own and race them.  I've only ever owned a 944 Turbo and a 924.  I sold the 944 Turbo relatively quickly and kept the 924 because I find the 2.5L a complicated and annoying engine to work on (though the turbo stuff likely makes this worse than the NA).

Twist the timing belt 90 degrees on the longest straight section, it should be hard to do so.

Twist the balance shaft belt 180 degrees on the longest straight section, it should be easier to do so, but stop at 180 degrees.  They will be a little noisy at first and you'll want to check the tension after a few miles.

http://www.clarks-garage.com/shop-manual/eng-10.htm

The tensioner tool is available to rent from some vendors and some enthusiasts loan them out, but you're right most don't buy the tool as you can set the tension manually if you know the feel.  Less expensive, more modern tension tools could also be used, but I don't have direct evidence of using them.

Stefan said:

They will be a little noisy at first and you'll want to check the tension after a few miles.

The last oen I did I set them a little tight and then just let them eat. But that was on a car that I didn't really care about and didn't feel like having to disassemble everything to check (turbo so there's lots of intake stuff in the way). Also, since nothing important is driven by the accessory belts you can just slap the intake back on and fire it up to make sure it sounds okay before you go through the effort of reassembling everything only to find out you got the tension wrong. The belt twisting test requires a little bit of "feel" to get it perfect, but even having never done it before you should be able to get it close enough.