In reply to gearheadE30 :
I'll take a look inside the distributor from my '79 to see what that looks like...
In reply to gearheadE30 :
I'll take a look inside the distributor from my '79 to see what that looks like...
That is a good question for the geeks at 924.org and while you are there check out the supercharger kit someone designed. With the low compression and terrible combustion chamber stuffing boost is perfect.
I do like that supercharger kit, but at the moment I'm trying to not go too deep with this one. Get it to a good driveable fun state, and then shift work back over to finishing the engine and transmission swap on the 325es. Once that's done and I figure out which one I'm going to keep, maybe I'll circle back for some boost.
I got the distributor back together after giving it a good clean and lube and modifying it for more mechanical advance. Still only one advance spring, which appears to be correct for the 1980 cars at least. They changed the distributors a lot over the years on these it would appear.
The way the advance mechanism is set up, one weight has a stop on it before the other so you get a fairly aggressive initial advance ramp, and then the last 5 degrees or so come in more gradually after the first weight hits its stop. It was just barely nice enough out to drive to work today, but I grabbed a quick video of acceleration as it finally pulls through the rev range the way I feel like it should. Yeah, it could use more power, but at least it is linear and doesn't feel like I need to be shifting before 5000 rpm. Much smoother and happier feeling.
Yes, it is fully warmed up. I'm not sure why, but the temp gauge sits at or below that first mark unless you're idling in traffic for a while. It is ~40F out, though.
Bunch of little fixes ongoing.
Replaced the driver's door brake. The aftermarket door brakes kind of suck, with a very pronounced "notch" where it locks fully open. The original door brakes are much more progressive
New hatch seal went on, and I realigned the hatch latches. Much quieter, and no more exhaust smell in the car. The hatch also actually unlatches and pops open like it is supposed to now.
Found a rattle - the heat shield on the exhaust manifold is cracked and 2 of the 3 holes holding it on weren't doing anything. I've just removed it for now, and will keep an eye on the spark plug boots. The remaining metal is rust-pitted badly enough that grinding and welding is unlikely to be effective.
Since it is now cold and snowy here in the midwest, I decided it was time to address the sound system. It was only making noise out of the center speaker in the dash, and what noise it made was crunchy and distorted. the wiring is very strange on these - the rear driver's side speaker and dash center speaker are wired in parallel, and the passenger rear speaker is on its own. All three speakers are 8 ohm 4x6 Blaupunkts.
this car had a Jensen RE-518 head unit feeding an audiovox amplifier of some sort. Very interesting old school setup, and as I was fiddling with it, it stopped producing sound altogether. The wiring was shoddy so I think I just wiggled something loose, but at this point I had already pretty well decided I was not going to reuse any of it.
If anyone wants this stuff, let me know. It will eventually go up on eBay.
there's enough space in the rear speaker areas to install 6.5" round speakers. Big upgrade over 4x6s, that just never seem to produce great sound in my experience. No, I didn't go high dollar with my speaker choice, but there was a pretty good deal going on over the holidays and the sound stage in a 924 with 3 speakers is never going to be great anyway. the crossovers are mounted in the cavity behind the speakers.
The front speaker will be a matching 4x6 Kicker unit. I tried to fit a pair of smaller round speakers up there, but the duct for the defrost vents is right there behind the speaker and there's just no way to get any more depth out of it. I want it all to be invisible when installed, which ruled out changing the mounting around too much.
Speakers are being driven by a small Kenwood class D 4 channel amp. This one is bridgeable, which I will use to drive the front speaker and will have to use the gain to balance output. This gives me the mono signal needed for the center speaker. It's also small enough to fit behind the center console. I am not using a head unit, and instead bought a small half-DIN equalizer with built in bluetooth. I've not done something like this before, but my hope is that it will resolve by concerns about ridiculous-looking head units. It hasn't shown up yet, so no pics of that.
Stock speakers looking truly dried out:
I did also make a few more discoveries about the car. The passenger rear window has been broken out before, and is not original. The entire rear quarter behind the panel card was full of shattered glass. It also looks like ~3 inches of standing water spent some time in the rear footwell. Fortunately nothing seems rusty besides the seatbelt hardware, there's just a defined water line on the carpet. So all of that will get cleaned up. Presumably that happened whenever the window broke, and fortunately it doesn't look like it spent long like that.
There's also been some evidence that this is not a 40k mile car. It needed tie rods, and the general amount of road grime under the hood just didn't make a lot of sense for something that really didn't get driven. The wear on the strut shafts also struck me as excessive for a low mile car. But the final confirmation was an oil change sticker I found under the driver's seat. 43,475 miles on August 2, 1999. The odometer currently reads 40475 miles, so that says it has rolled over. Considering all of the parts I replaced were original, I would say it definitely has not rolled over twice, and the odometer worked until I broke it, so it probably really does have about 140500 miles on it now.
Am I putting too much effort and money into this unloved old car? Probably. But it is more fun than I expected, and that further complicates my decisions about what cars to keep and what to sell. First world problems, I know.
gearheadE30 said:But the final confirmation was an oil change sticker I found under the driver's seat. 43,475 miles on August 2, 1999. The odometer currently reads 40475 miles, so that says it has rolled over.
with 4 out of 5 digits the same, and it's an analog odo, my money is on "odometer input broke sometime before that last oil change, and the thousand digit has rotated in the wrong direction from 3 back to 0."
the odo in my 86 944 changed readings in a similar manner.
Second the broken odometer theory.
In reply to AngryCorvair (Forum Supporter) :
The odometer in my 924S was broken when I got it. Took it apart and replaced the gears, and now the trip odometer advances properly, but the main odometer sometimes has a mind of its own (I know I at least mis-aligned the numbers). I am NOT taking it out again...
Agree with Angry. Odometer broke for sure, very common
I agree with the broken odometer theory.. is it possible it broke previously and rather than fix it was replaced with a working unit from another car? I am not familiar with Porsche but every odometer I have ever seen when it rolls over the first digit isnt aligned with the others anymore.. it rolls slightly as an indicator its over 100k. Just a thought
I've been following this thread and keep seeing these cars everywhere on FB.
They're pretty-light 2400lbs according to wikipedia. Is there a path to using them as a challenge car that doesn't involve weird LS engine swaps?
EDIT: Target for the challenge would be around 300hp for the engine, a drivetrain that can take repeated 1/4 mile launches, and a tire package that can put the power to the ground.
The broken odometer theory is pretty darn interesting...I'm not looking forward to pulling it out and trying to remove that gauge bezel without destroying it, but I would like to get it working again. This one does still have the first digit aligned perfectly, and I'll have to see if I have any other paperwork with 4X750 on it just to see.
I am quite sure it's the original gauge, this car is so original and untouched that I'd be pretty shocked if the thing someone opted to swap out was the speedometer. There's no evidence that the dash has ever been apart exept for the aftermarket head unit - no tool marks on hardware, missing hardware, random zip ties, or anything like that. And many of the bulbs were burned out anyway. If they couldn't be bothered to replace bulbs, I doubt someone would replace the whole gauge. Plus, I'm the third owner - this thing hasn't ever had the "cheap Porsche as a first car" owner that usually butchers at least a few things.
@CrustyRedXpress - Yep, they're all over and cheap in non-running condition. Mine went across the scales at 2880 lbs with me (185 lbs) in it and a full tank of gas (~15 gallons I think).
The 2.0 can get into the 250hp region pretty well with boost. They have terrible airflow characteristics but seem to be quite sturdy. But the 2.0 NA cars have a weaker transmission and a thinner torque tube shaft along with a different bellhousing and oddball clutch vs. the Porsche - engined 2.5+L cars. The only straightforward swap into the early 924 is the Audi 5 cylinder (I think 7A?) engine, which is easy to get those numbers out of. A gentle driver could make the drivetrain last, especially if you start with a 924 Turbo and just add an intercooler and turn up the boost.
For the 2.0 cars, realistic goals without an engine swap are ~150hp NA or 200-250 hp with boost from what I've seen. Challenge budget depends on your fabrication skills, but if you learn how K-jet works, you can do it without major fuel system modifications.
Otherwise, the later 924S or the 944 are a better-supported solution for engine swaps. Stronger torque tube, plenty of adapters available for that bell housing pattern for an 07K, LS, etc, stronger transmission options, stronger clutch options, and a lot more room under the fenders for tires in the case of the 944. The early 924 has a lot of small quirks that make things harder too, like an engine that hangs from its mounts instead of sitting on them, and some suspension and steering parts that were completely changed for the 944.
No matter what you choose, hard launches on a prepped surface are dangerous in a high power transaxle Porsche. Ring and pinion, torque tube, and rear axles are all somewhat known to fail without upgrades. Solutions exist, but most aren't in a Challenge budget.
Very cool. First Porsche I ever rode in was a 924S. There have been several for sale not far from me that have me wanting one. Actually just ran across an old PDF of the build sheets for the old 924D Spec build cars for SCCA.
Those D Production cars are very interesting, I've done some research on them as I try to decide what I want to do with this car. A lot of the stuff they did for those isn't really too far out of the question for a street car, but even those never quite got to the 100 hp/liter mark. They used the 931 cylinder head with some custom pistons to get the compression ratio back - the 931 head has an actual combustion chamber, and the ports are dramatically better for flow velocity.
After probably way too much effort, the sound system works. This is the first time I've ever run into a case where the voltage drop in the factory wiring was so bad that it caused the amplifier to clip. Ended up having to run dedicated power and a better ground to take care of that, and fixed a couple other things under the dash while I was in there. One of those projects that seems so simple, but took all day. The blue light is a little annoying, its the status light for the bluetooth so it does turn off if you use the aux input. It sounds good, but the amp doesn't have enough punch to really get much bass response. There's just not enough space for a bigger amplifier in the center console, so it is what it is. 180 watt RMS/400 watt peak Kenwood class D unit, it does just fine, I'm just spoiled by the sound system in the Suburban.
Still need to re-glue the rear door cards before I put those back in, and clean up a few things while it's apart. Hopefully I won't need to tear into all this again for a very long time.
The odometer gear breaks when someone tries to reset the trip while the car is moving. If your odo is moving at all that is probably not the case but after so many years it might have been fixed then broke again.
The dogleg 5 speed is fun on the track but can be a pain in traffic on the street. I have a real thing for them thanks to a neighbor 50 years ago who bought a pantera the summer I got my license. So the first sports car I drove had the dogleg and now if I find a car with one I must buy it. Bought a 91 300 SL stick because of that shift pattern. Oh, it also had a 7000 rpm redline so that helped.
My odo is not moving at all, it's completely dead. I looked into pulling it out last night, but it looks like the steering column needs to come apart to get the cluster out. I need to be able to move the car out to paint a few things, so that's going to wait a bit. I wish it was like the BMW stuff where you just buy the right gearset based on a motometer or VDO cluster, but it seems like there is a lot of variation in these and you have to see what you've got first.
I've never actually driven a car with a dogleg box, it does seem like it would take some reprogramming of my brain. These only had the dogleg box in 1978 and 1979 in the US I think, and it was optional in Europe over the standard 4 speed transmission.
I nearly bought a manual transmission 300 SL years ago, but just couldn't scrape the money together. Apparently they only made a bit over 300 of them for the US, very cool cars. I didn't realize they revved that high; I don't normally equate Mercedes with high rev engines.
I was an idiot with the sound system and was causing myself all kinds of issues. Clipping is resolved, it sounds wonderful (or as wonderful as a 3 speaker system will sound) now. I have been using those foam XTC speaker surrounds on the last few systems I've installed, and I didn't realize that you are supposed to cut holes in the back and just use them for shrouding/water protection. I had a random thought about it last night, and decided to pull one of them out just to see what it did. Well, lo and behold, the speaker behaves visibly different and no longer clips! Duh. Zero airspace behind the speaker means zero bass without massive mounts of power, and I think some strange speaker dynamics as well. Pulled the other one, way more happy with it now. Also re-glued the rear panels as the vinyl was mostly separated and got those reinstalled. Windows will go back in sometime later this week.
Starting to look at the engine mounting. Thanks nlevie for your help with this, makes it much easier when I can develop something without taking the car down for weeks while I wait on parts! Pictures of this stuff seems to be hard to find online, so going into a bit of excessive detail here in case it helps someone later.
The engine hangs from the mounts in an early 924. The two bolts on the metal bracket mount to the frame rails, and the single stud mounts through arms that come off the sides of the block and extend down below the frame rail overhangs. The frame rail overhangs are solid between the arms of the
This is a driver's side engine mount. Rubber, with primary stiffness in the fore-aft direction. Some sagging but generally usable. You can see there is a lot of vertical free travel before it would hit the travel bumpers, but it's probably sitting on, or nearly on, the lower travel bumper when installed. You can see where the rubber is "clean" where it touches.
The bottom area of the mount is open. The outer section of the mount is rubber over-molded steel, and it appears that the outer steel frame is the same as the driver's side one you'll see below. Where the rubber passes through the hole limits the amount of radial deflection.
The passenger side mount is the one that always fails. The spring is supposed to do most of the work supporting the engine, with the rubber donut being the lower travel stop and the little rubber cap on the top of the steel washer being the upper travel stop that hits the frame. The lower rubber donut ID also works as the radial travel limiter. This one is broken, and you can see where the rubber donut should be pushing against the steel frame instead of just free-floating.
Disassembled, you can see the broken spring. The spring fails because the cowl drain sends water straight into the rubber donut from above, so the spring sits in water and eventually fails due to rust propogation. This dramatically reduces the stiffness of the mount, so the engine sits very low on the passenger side. This puts the exhaust manifold into contact with the heat shields along the frame, and will cause contact in aggressive driving. It also results in the oil pan hitting the crossmember.
The mounts have been NLA for years, back to about 2005 as far as I can tell. Someone had a run of replacement springs made, but those are also long gone.
Vibra-technics does make a mount for the early 924, but by all accounts they are very stiff. I believe they are around $300 a pair. The EA831 is not exactly a smooth engine, with a truly astounding amount of reciprocating mass for such a small engine, and no balance shaft. This isn't ever going to be a track car for me, I want it to be fun on the street.
I have a plan for some solid rubber mounts that should work well in this application. My hope is they'll limit some of the free movement in the drivetrain without adding to NVH too much. I've used similar mounts for 4-cylinder diesel engines at work with some success, so I think there's a chance it will work. The design of the factory mounts is such that I should be able to use the stock bracket. About half the bits are ordered, I'll update once I know if it is going to work or not.
My 79 had a failed pass side mount also but I figured it was heat from the header. Went to the grocery store with the new mount and found something in a metal can (fruit or pasta sauce I think) that had a can just big enough to go over the mount. Wrapped it in insulating foil and used that.
Yep, heat shielding is high on my list. That mount is RIGHT next to the manifold.
Parts are here, so far so good. Isolators are maybe a hair too stiff but they sell a softer version the same size that I can swap out or mix and match upper and lower halves, and they are cheap. Even though the diameter through the bracket is small, the bushing shape around the sleeve opens up in the middle to provide some extra cushion. Nice and fat vertically where I want it. These are rated for 380 lbs each, the EA831 weighs a bit under 300 lbs depending on who you believe online. The next softer mount is in the mid 200 lb each range.
My super accurate durometer measuring device (my finger) suggests similar rubber stiffness to the stock mounts, but obviously a completely different design so not really comparable. I wanted to err on the stiff side since these mounts also have to support force from the transmission and torque tube.
I've got a sleeve coming to weld into the mounts so the bushings are properly supported. Just sitting in the hole in the picture.
Put the rear windows back in last night, noticed that my re-glued rear door/side panels already have minor lifting. I've tried several different fabric adhesives over the years and have yet to find one that works really well. Any ideas? The material has shrunk so much that the vinyl doesn't go up under the window seal anymore, so at least they are easy to get out if I want to re-do them again.
Right after I redid the distributor, I discovered the thrust washer for the mechanical advance sitting on my workbench rather than inside the distributor where it belonged, so I put that back in last night. I also tested the vacuum advance while it was out because it felt like that wasn't working right since the rebuild. Turns out there are 3 different screw lengths holding that thing together. Two short screws, and two long but one of the long ones is a mm or two longer than the other. I had them in the wrong place...the end of the longest one was just barely touching the part of the vacuum advance that rotates, locking it in place. So that's fixed now, and I've also confirmed the advance diaphragm is in good shape and doesn't leak. Duh. Nothing like creating a little extra work for myself.
Put in another order of parts, valve cover gasket being key among them so that I can check the valves and camshaft condition. The rear cover on the head has a slow oil leak that I'm going to ignore for now - the gasket on the distributor cured most of the leaking back there. The only significant leak left is the oil pan gasket, so I ordered one of those too. Cheap enough to have on hand for whenever I get the time, fortunately it only leaves a few small drops on the ground.
O2 sensor is a whopping $13 for this car, so that also made the list. It surges noticeably in closed loop, but it's fine in open loop (idle, over 3500 rpm, or whenever the second throttle plate is open), so hopefully it's just a deteriorated sensor. I still need to confirm fuel pressure, set idle mixture, and get an oscilloscope on the frequency valve to understand what all it's doing, so there's a few things on the list there, but these old cheap one-wire sensors are not known for durability. This one appears to be original.
I just recovered the headliner and the pillar covers in my e36. I used 3m headliner adhesive on the headliner and one of the trim pieces and Barge cement on the rest. We shall see how they last but so far so good. It's been months with no lifting but it's also been in the garage the whole time
Interesting, I used 3M 77 (super 77? something like that) because the the can of 3M headliner adhesive I had said it wasn't great for heavy materials like the vinyl on these panels, but would expect them to perform similarly. I do think some of it might be operator error - you are supposed to spray both surfaces and let them tack up before mating them. I didn't wait long enough on the first panel (waited 10-15 minutes on the second one) and the first panel is the one that's lifting. Might just have to retry at some point, once I know if the driver's side panel is going to hold up.
I finally got time to check pressures - thanks porschenut for the help with the test equipment, that made it easy. Some useful discoveries, some I'm still trying to understand.
lower control pressure = richer mixture, higher control pressure = leaner mixture. I need to keep repeating this in my head...
So all of this tells me that my fuel system is good on the supply side and on the control pressure side, and that I don't have the common WUR filter plugging issue which would result in abnormally high control pressures. All good there.
What I am not 100% on is the frequency valve and if it's working correctly. I totally misunderstood how it works until today - I thought it was another control pressure meter, but it isn't. It actually is a "vent" to bypass pressure from the injector diaphragms. To enrich the mixture, the duty cycle increases to vent this compensation pressure to return, and to lean out, the duty cycle decreases. Cars without the lambda system maintain system pressure in these diaphragms at all times. All of these regulated bypasses must mean there's a ton of unused fuel flow in this thing.
When I first got the car and the frequency valve didn't work at all, it was closed, resulting in a very lean mixture. From my testing, it's a normally closed solenoid valve. After testing all the system and control pressure bits, I wanted to make sure this was working...but tripping the switches on the throttle body did nothing. I went to check the o2 sensor figuring I could at least measure its output voltage and....the wire went to nowhere. Disappeared between the starter and the heat shield that covers it. Not a lot of space in there, but I was eventually able to free the wire and connector from under the shield. Of course it is rock hard from heat, and both it and the connector it is supposed to be plugged into disintegrated when I tried to connect them. But that immediately resulted in different running, and I was able to adjust the idle mixture. So now I have a nice steady idle and a much smoother engine - it was running pig rich at idle.
My multimeter has some frequency settings on it, and the Hz setting seems to be trustworthy - 69 Hz, near enough to the 70 Hz I was expecting. The "%" setting I'm not sure I trust yet. It seems to bounce around a lot, somewhat nonsensically. Anywhere from 60 to 75% from what I saw, and the WOT switch didn't lock it in to any kind of fixed value that I could see. I'll play with it some more tomorrow and see if I can get that reading to make sense, I was just tripping switches with the car idling in the driveway.
Another test drive, another improvement - it does run a lot more smoothly, but it's still not perfect. Driveability is definitely better, but still some surging. It wouldn't surprise me if that old O2 sensor is shot from living in an over-rich environment for so long. WOT once again seems marginally better, like every time I fix something I pick up a few more of those missing horses. Internet lore suggests the frequency valve defaults to 50% duty under all conditions if the sensor is unplugged, so it makes some sense that I'm probably getting a bit more fuel at high load now.
And of course, pictures. Sewed up the hole in the shift boot, so it looks good again:
Dog has discovered the viewing platform:
And the 924 continues to be hilariously small compared to modern cars:
Went for a drive and measured frequency valve behavior this morning. there's no "normal" range quoted in 924 literature, but the 911 CIS-lambda quotes 45%-65% is normal.
I inverted the leads originally. Correct connection is the ground to the test port in the engine bay and positive to a ground location, otherwise you get inverted duty cycle signals. I've not quite wrapped my head around why this is, but that's what it seems to be.
During warmup, duty cycle is 50%. Oddly, unplugging the coolant temp switch makes no difference here, even though I've confirmed that switch is working fine. It actually appears that warmup cycle is governed by o2 sensor getting hot enough to start switching, not by coolant temperature.
WOT is 65%. WOT doesn't appear to be an overriding switch where WOT always is 65%, but instead seems to be WOT + engine speed.
Light throttle is 40-50% duty
Idle is 30-40% duty
My understanding is that higher duty cycle = more fuel bypassed from the lower chamber of the fuel distributor, which means richer mixture.
Things I don't understand:
EDIT - rather than immediately making another post, I tried running with WOT unplugged - it never goes into open loop without the WOT switch. With the WOT switch, it goes into open loop 65% at 4000 RPM + WOT. It still appears to run CL below that, or if it isn't, it's a very fluttery ~50%. Still no idea on the idle or coolant temperature switches.
I did also time a 0-60 with a very lazy launch at about 10.5 seconds. Still slower than it should be, C&D got 9.9 seconds out of a 95hp 4-speed earlier model though I'm sure they beat on the car more than I want to, and the 4 speed gets you to 60 in second. But at the very least, it's close to what it's supposed to be now. For comparison, they got 7.5 seconds out of a first-year 924 Turbo, and I've seen comments that the 1980 cars are usually in the 10 to 10.5 second range.
Well poo. Guess these were on the shelf a little too long...leaking from the adjuster button.
I've been confused about the surging I have been feeling, so I did some more testing today. Discovered that where the spec is 19-25 degrees of advance at 2500 rpm with base timing of 0, I am only getting about 15 degrees. I found this after doing a base timing test, trying to understand if any power was left hiding there. I did 2nd gear acceleration from 2000 rpm to 6000 rpm, which is 17 mph to 50 mph on the GPS, starting at 0 degrees base timing and going up in increments of 5 degrees. I expected to run into detonation around 15 degrees and then back off and see if there was any difference, but to my utter surprise, I made it up to 25(!) degrees of base timing with no knocking or pinging before I decided something wasn't right. 20 and 25 degrees did the best times and also fixed my surging issue a bit, but they idled horribly.
It can't be that the timing marks are off, because with a 6 bolt pattern that would put me 60 degrees out of time and there's no way the car would run that way.
I'm not sure what's going on, because the distributor is correct for the car and appears to be working fine when disassembled. Clearly though, it isn't right. More to come on that.
In the process, I accidentally learned another thing about the frequency valve. I confirmed that it does function at idle rather than running a set duty cycle like WOT does, and I also learned that it can run all the way down to 0 duty cycle....because I heard it happen and thought it had stopped working again. CIS has the equivalent of an idle mixture screw on the fuel distributor, and mine was too rich even though I thought I'd gotten it close. The result was that the frequency valve didn't have enough authority to dial in the AFR.
The problem is that the frequency valve duty doesn't seem to be modulated all that quickly, or has a ramp rate cap. When the duty goes to zero, if you give it throttle to pull away, it takes a notable amount of time for it to kick back on so you get this horrible lean bog for maybe half a second. So that's seemingly fixed now, or at least a lot closer - feels like I'm finally getting really close to this car running "right".
Another pile of parts came in, so I replaced some trim clips and grommets and checked the valves. All of them were pretty much in spec, so that was good. The cam oiler bar is also in good shape and the cam shows no signs of wear, which is great because these cars do have a tendency to wipe cam lobes if not maintained well. The inside of the engine does have some schmoo in it but I think a few good synthetic oil changes will help clean that out.
There's a bit of noise coming from the engine when hot so I removed the belt just to make sure the alternator wasn't the cause of the noise - it isn't. Sounds like a dry ball bearing or possibly some piece of metal resonating, but it could also be the engine contacting something due to those engine mounts I haven't fixed yet. It's pretty minor and you can only hear it with the hood open so I'm not too worried. It passes the torque tube bearing noise test, so that makes me happy at least.
The valve adjustment is goofy on these - solid tappets, and there's a screw with a tapered flat running through the middle. To adjust the clearance, you turn the screw one full revolution in or out with an allen key so the tip of the valve then rides on a different part of the taper. It's easy, but man that's a lot of mass in the valvetrain. Everything is properly massive compared to newer engines. Spec is 0.1mm intake and 0.4mm exhaust, which is a pretty darn large amount of clearance on the exhaust compared to what I'm used to.
Then took the car to go have dinner with friends yesterday, their house is down a pretty good back road that's got a mile-ish long section of curves with really good sightlines. It's no rocket, but it is a lot of fun on the back roads. I'm anxiously awaiting the arrival of the torsion bars and shocks so I can get the rear suspension done - it understeers aggressively on throttle right now, but it is really unstable entering corners, so you have to make sure you're on throttle by the time you turn in or the chassis gets overwhelmed with weight transfer on multiple axes. The people on the internet who say you can install 250 lb front springs with stock torsion bars and have a good-handling car are wrong - fortunately it was never the plan to leave it this way.
This little stretch of road did highlight the braking system...after only a mile of fun, with a car that's still a bit down on power on very not-sticky tires, the smell of brakes was strong and the pedal feel was starting to change. I've driven that road a hundred times, in the Tahoe, in various E30s, my old SVX, etc - I've never had brakes smelling after that stretch that I can remember. I'm sure good pads would help - it's just got OEM street replacement stuff on there now - but brake temperature control definitely seems like a weak point on this car. The fronts are actually the same diameter as the E30s I'm used to at ~260mm, but they're solid rotors instead of vented. It's a street car so it doesn't really matter, and would be fine for an autocross, but I'll just have to keep an eye on it if I'm on longer fun back road stretches or if I ever do a TNIA event or something with it.
Once it gets warmer, I need to do some scrubbing under the hood, too.
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