In the E28 the in tank pump seems to help when the fuel level in the tank is below 1/4, if it's not working then you can get some cutouts through corners as the main pump sucks air. It may be worth going and hitting some twisty roads with a low fuel level and make sure it's not a problem, the fact that you aren't trying to suck through an old dead pump may take care of that problem too.
Adam
You really should put the in tank pump back in there. When you are low on fuel it prevents the main pump from cavitating. That cavitation kills the main pump rather too quickly. Also Adam's comment above is accurate, cornering loads with low fuel level are when it cavitates first. Early E9 cars did not have it and there was a cornering stumble problem that caused a recall campaign to install an in tank pump. I did a few of them
adam525i said:In the E28 the in tank pump seems to help when the fuel level in the tank is below 1/4, if it's not working then you can get some cutouts through corners as the main pump sucks air. It may be worth going and hitting some twisty roads with a low fuel level and make sure it's not a problem, the fact that you aren't trying to suck through an old dead pump may take care of that problem too.
Adam
TurnerX19 said:You really should put the in tank pump back in there. When you are low on fuel it prevents the main pump from cavitating. That cavitation kills the main pump rather too quickly. Also Adam's comment above is accurate, cornering loads with low fuel level are when it cavitates first. Early E9 cars did not have it and there was a cornering stumble problem that caused a recall campaign to install an in tank pump. I did a few of them
The upshot is that I rarely have less than half a tank in this car. For rally, the weight of fuel is typically helpful for traction (where the e30 tank is), and due to the unknown and frequent hold-ups in rally (sitting between stages, long transits, etc) it's never good to run anywhere close to empty (especially with a fuel gauge that is not all that accurate). Plus, the side loads of corners in rally aren't what they are in road racing. We've never had any issues with fuel starvation, so that's not really a concern.
In any case, my plan is to put a high-pressure in-tank pump in eventuall (primarily because I dislike having the pump down under the rocker where it can get hit by rocks). I have a brand-new fuel tank going in sometime this summer and when I do that, the intention is to go HP in-tank and run new high-pressure lines where there are currently low-pressure (i.e. above the tank and exiting the tank hard lines to the current pump position.)
So yep, it's on the list. This is pretty much just a "get me through" thing until I do the tank, which I'm not really looking forward to doing, so keep pushing off lol. This car won't see below half a tank of gas before that time regardless.
irish44j said:time to cut and modify the old skidplate as a stopgap. Remember, this is 1/8" stainless steel, so it's pretty damn thick.
The 3/8" thick steel skidplate in teh RX-7 laughs at your puny skidplate. As well as everything else.
(Yes, it is heavy. I calculated it at 70 pounds. It also survived me hitting "something" late at night on I-71, hard enough to send the car airborne and mangle the mounts, but the oil cooler and radiator were undamaged, so that 70lb paid for itself in spades that day. Err, night.)
Knurled. said:irish44j said:time to cut and modify the old skidplate as a stopgap. Remember, this is 1/8" stainless steel, so it's pretty damn thick.The 3/8" thick steel skidplate in teh RX-7 laughs at your puny skidplate. As well as everything else.
(Yes, it is heavy. I calculated it at 70 pounds. It also survived me hitting "something" late at night on I-71, hard enough to send the car airborne and mangle the mounts, but the oil cooler and radiator were undamaged, so that 70lb paid for itself in spades that day. Err, night.)
you literally have thicker skidplate than any stage rally car in the country, then, lol...
In reply to irish44j :
It was $25 at Summit in their clearance rack. it's for a Chevy K1500, but turned around backwards it fit perfectly.
In reply to Knurled. :
not for nothing, but don't you think taking 50lbs off the nose of your car would be beneficial for rallycross? I mean, even my oversize SS skidplate is only about 30lbs, and it's way heavier than anyone else's in our region, and heavier than most stage cars (most people use aluminum).. I guess since your engine doesn't weigh much you have more allowance up there, but still, 50lbs is a lot of a 2000 lb car.
In reply to irish44j :
Good thing I have a 2400lb car, then!
(The engine is not light. V8 swaps tend to keep the same weight. What I have is good weight distribution. Stock RX-7s are 100lb or so nose heavy but with some resitribution, I was 100lb nose-light, WITH the skidplate, and before the ~40-50lb heavier 9" rear)
irish44j said:In reply to Knurled. :
not for nothing, but don't you think taking 50lbs off the nose of your car would be beneficial for rallycross? I mean, even my oversize SS skidplate is only about 30lbs, and it's way heavier than anyone else's in our region, and heavier than most stage cars (most people use aluminum).. I guess since your engine doesn't weigh much you have more allowance up there, but still, 50lbs is a lot of a 2000 lb car.
Not everyone... Pretty sure my 3/16 steel plate one is heavier. Although, mine is smaller, so maybe around same weight.
bluej said:irish44j said:In reply to Knurled. :
not for nothing, but don't you think taking 50lbs off the nose of your car would be beneficial for rallycross? I mean, even my oversize SS skidplate is only about 30lbs, and it's way heavier than anyone else's in our region, and heavier than most stage cars (most people use aluminum).. I guess since your engine doesn't weigh much you have more allowance up there, but still, 50lbs is a lot of a 2000 lb car.
Not everyone... Pretty sure my 3/16 steel plate one is heavier. Although, mine is smaller, so maybe around same weight.
damn, yours is that thick?? Never noticed.
I will note, of course, that I also have the "U" support bar there as well, so that probably adds 5lbs or so.
So, all packed up for tomorrow's season opener rallycross, in which there are 16 cars in my class (almost all of which are fast drivers) and 65 total entries. So, we'll see how this goes..
Also, it turned out that my buddy Jason was heading down through Harrisburg, so he stopped off at Rusty's house, and grabbed the Integra wheels rusty picked up for me for $60. "Rally Mail," as we call it.
I decided to take the Porsche to pick them up at Jason's about 20 minutes away, to see if I had fixed the stalling/fuel issue. Seems that I have, No stalls and I pushed the car pretty well.
some curbing, but otherwise they look pretty decent for a $60 wheel. I may or may not use these for a street wheel (and sell my Euroweaves since they are wasted on a rallycar that doesn't get driven often). I also got a set of Mini Cooper 15s down in N.C. (another fellow rally driver picked them up for me), so now I have two sets of 15s. I want at least one more before I start unloading most of my 14" stuff...
Will do a short recap of today's first rallycross of the season, and a longer one later. In short: In the morning, I had a lot of trouble figuring out how to drive this car with so much more power, and it showed both in my mediocre times and my cone count. In the afternoon, made a few changes to the car setup and to my driving approach and smoothed it out and put up some pretty good times in a field of very fast movers. In the end, dug wa too big a hole in the morning and only managed a 6th place finish (out of 15 or so entries in the class), but the engine held up well and with some adjustments to the car i think it can be pretty fast.
Here's some vid of one of my better runs, if you're interested (with good engine sound and a bit of transmission whine).
ok, so recap of the first event. Saturday was 75 degrees and beautiful. When I left my house at 530am Sunday it was 60. At the mountain, the temps quickly went down and it was really windy, in the 40s all day but felt a lot colder (and so much blowing dust)
Anyhow, one of DC's largest events ever with almost 65 drivers registered. MR class as expected was big, with over 15 drivers registered. Making it even more intense, we had all the front-of-the pack regulars from last year - Nick D in the M3, Sennett in his M52 e30, Stephen and Chris in the 325i, Neil and Eric in the 325i, and others. So right there is about six guys who have won at least one event in the past year or so. To add to that, Jeff Geier, who was one of the faster guys two years ago, returned from his year-long adventure motorcycle trip around the continent and got right back into going fast in his co-driven 325. Aaaand, Jeremy Sitar, one of the fastest guys in Appalachian region 2 years ago, returned to rallycross in his e36 328i. To add to that, Dan Gugger left his M10 e30 at home and showed up with a Porsche 944 on fresh rally tires. Plus we had a couple Miatas and a couple BRZs, plus a few other newbies. So that's a lot of fast movers, any of whom can win on any given day.
Huge group....65 cars coming up the hill to grid
The MR crew
From the start, I knew it was going to be tough. With the M42 it was quick and balanced, and you coudl pretty much just put the pedal to the floor and go. On my first couple runs, I found out the hard way that the torquey M50 isn't going to have that, as I almost spun a couple times and killed a few cones in the process. My times weren't awful, but they weren't great either. I was running soft DMack gravels up front and hard DMack gravels on the rear, and keeping the tail under control was quite a bit of work, as the car would over-rotate in anything tight. This was exacerbated by only having replaced one trailing arm, while the other one was still 1/2" toe out, giving some tendency to snap oversteer under braking.
By lunch break my cones and some sloppy driving overall put me out of contention, something like 15 seconds behind the class leader, Nick. So, people ate lunch...
Meanwhile, I messed with the car. I switched on my Maxsports (much softer tread and sidewalls) to the rear in place of the hard gravels, and I strapped two spare wheels/tires into the trunk to get some weight in the back.
So up we went for afternoon runs. And whadya know....I worked on modulating the throttle more and "point-and-shoot" more coming out of turns with later throttle application, and on the 2nd run of the afternoon I had the fastest time in the class for that run. The rest of the afternoon runs I ran pretty consistently. A few people had faster runs and I did pick up another cone, but overall the car felt pretty good and I started to get the hang of what it wanted to do. Overall I think I picked up a couple seconds on Nick in the afternoon, and finished in 6th place. So, not terrible considering the lousy start and the huge amount of talented competition.
Nick won, beating Sitar by 2/10ths of a second and once again hitting no cones (neither of them did) - though Nick, remember, I know you hit one that didn't get counted, because you said you did ;) But, it only counts if someone calls it in!
So, this isn't autocross so what you did on one or some runs is irrelevant. However, for the sake of metrics I did a quick look at just the afternoon runs at the top of our class:
Nick: 334.3 seconds (no cones)
Jeremy: 331.6 seconds (no cones)
Chris H: 335.1 seconds (no cones)
Eric E: 336.9 seconds (+1 cone = 338.9)
Stephen: 335.8 seconds (+2 cones = 339.8)
Me: 333.8 seconds (+1 cone = 335.8)
Jeff G: 338.3 seconds (+4 cones = 346.3)
Neil : 339.6 second (+1 cone = 341.6)
Josh S: 341.1 seconds (+3 cones = 347.1)
Takeaway: If you are pretty quick and hit no cones, you will probably be on the podium
Sooo....on raw time alone I was faster in the afternoon than everybody except Jeremy, and he was absolutely flying. The one cone i did get was on my last run with Julian riding shotgun where we were kind of goofing around late in the course and I overshot the turnaround. So, afternoon *could* have been a bit faster, to boot. So, I feel pretty good about the afternoon driving - looking at the numbers I was a bit better than I thought I was. With some fine tuning hopefully I can get back into contention at the next event, just have to calm down on cones and be consistent.
So, some takeaways and notes:
I need the "rally weight" in the trunk with these M3 springs, just like I did with the M42. Two tires seems to be about right, with a mostly-full tank of fuel. Now I have enough power to not worry about weight.
Front springs felt GREAT. I went up 25lbs of rate, but they actually feel way better than they did before.
Refreshing my braking system paid dividends, as the brakes felt really good and were only tranction-limited in one or two spots.
The drivetrain feels VERY responsive in all ways. I will note that with sold motor and transmisison mounts, man, my tranmission has substantial increase in NVH. Even the brand-new throwout bearing I can hear easily with the clutch pressed, With the clutch out and in neutral, there is a high level of layshaft/input shaft bearing noise from the transmission. It was likely there before, but I had soft poly mounts on it before rather than UHMV through-bolt ones. Getrag transmissions from e30s are known to have noisy bearings at high miles and it isn't said to be a major issue, but boy it is very apparent now. Also an audible gear whine that I couldn't really hear before. Just to test whether it's just the extra NVH from the sold mounts vs. something actually wrong, I'll probably throw some stock mounts in this week and go drive around and see what it sounds/feels like.
Diff: The 4.10s are just too short. Luckily this course was more technical than the usual Panthera courses (the two big straight hills were too torn up and rutted to run), so I could do the whole course in 2nd, but on a "typical" course here I would have needed 3rd a few times, which I'd prefer not to do. So I will almost certianly put my 3.73 LSD diff back in the car. It was a bit too long for the M42 that liked to rev, but should be just about right with this engine.
I pulled that diff off the shelf and tested the breakaway torque on the LSD, and it was taking close to 60lb-ft to break away - so that says it's locking up right about where it should.
So, will get that diff and the other trailing arm in this week. My new skidplate should be in tomorrow as well so will get that fitted up this week.
random: This newcomer e30 was just an M20, but the previous owner had planned to put a Yamaha Taurus SHO engine in it with ITBs, so built this hood to fit it (and never fitted the engine).
Also since I can't find his thread, here's a good one of Shawn (moxnix)
Not much to show tonight. My new skidplate from #Red46 came in. Ben builds a nice selection of stainless steel rally/rallycross skidplates for e30s (including ones with engine swaps) and other cars. This one is substantially larger than those and built to my specs, just like the one that's been on the car for years. They're really nicely done and very heavy-duty - so definitely check them out if you need a skid for your rally or lowered or regular e30. www.red46.net
He also laser-etches the logo into them, which looks cool in a subtle way
Just for fun, I shot the front half of mine with some translucent red paint. I know it'll get scraped off pretty fast, but I like color, so why not
I need to take the other one off and make some marks to drill the mount bolt holes, which I'll take care of sometime this week.
Also put together the new bearing and hub for the second reinforced trailing arm, which I'll put on this week. I have a bunch of cans of red spray paint (from Pat Henry, leftover from when he painted his Comanche), so in the interest of not wasting money, pretty much anything under the car gets painted red.
While I have that out, I'm going to swap out my 4.10LSD with my 3.73 LSD to try to get better gearing for rallycross. The 4.10 will probably be the one to use for stage rally, but don't have one of those anytime soon and want the car set up best for rallycross at the moment.
I need to retrofit some mount studs to this diff like I have on the 4.10. Likely will just cut down and re-use the wheel studs I just replaced on the hubs for this purpose, which is how the 4.10 is set up.
60 ft-lb????
No wonder you can turn in.
Knurled. said:60 ft-lb????
No wonder you can turn in.
Probably closer to 50, really. That torque wrench tends to read a bit high and 60 indicates "brand new" plates and springs in an e30 medium case diff now that I think of it Though, this diff was bought from a guy who raced, so I guess it might have an additional clutch pack in it (i.e. a cheater diff). I've never looked to see. Either way, as long as it's over about 40 I'm fine with that.
As to what I can do now, well the one on the car is an older 4.10, which last tested last year was around 45-50.
I'm interested to see whether you chew up the plates in that LSD with the more powerful engine. The breakaway on our RX7 was set to around 75 ft-lb and I felt like that was a little too slippy and hard to predict on corner exit sometimes, although braking and turn-in were fantastic. The XR4Ti's LSD is 200ft-lbs+ and needs to be beaten into submission (or a yank of the handbrake) to get it to start turning... but then again, the car is sort of a pig and was actually worse on turn-in with an open diff.
Would you mind sharing the dimensions/attachment methods of your skid plate? I'll eventually want to upgrade my "off-the-shelf" Red46 unit and it looks like you're getting some great coverage with that thing.
artur1808 said:Would you mind sharing the dimensions/attachment methods of your skid plate? I'll eventually want to upgrade my "off-the-shelf" Red46 unit and it looks like you're getting some great coverage with that thing.
The front attachment is about 2-3" forward of the upward bend (to keep the bolts from being directly hit). There are three bolts, and all are attached to tabs off the front of the U-shaped crossbar (which runs from the forward frame rails). The tabs have weld nuts in them. If you go back a page or two you can see a photo of the very beat-up U-brace made of DOM tubing.
The rear attachment is 3 or 4 weld nuts inserted into a metal U-profile bar that's about 18" long and is welded directly to the bottom of the car's front subframe (so I didn't drill into the subframe). There's a pic of it somewhere earlier in the thread, but it's not all that exciting.
I like to use through-hole weld nuts in a lot of places in this car (with M12 bolts) for things like underbody protection and holding the skidplate
I'll try to take some new pics this week while I'm installing the new skid.
The skid also has an 18" or so long narrower HDPE "panel" bolted to the trailing end of it, which runs to the transmission tunnel crossbrace and provides some measure of protection from debris getting up into the transmission and driveshaft/ujoint/shifter area. It's not all that strong, but it's not acting as a skidplate per se, just environmental protection from mud/rocks etc.
¯\_(ツ)_/¯ said:I'm interested to see whether you chew up the plates in that LSD with the more powerful engine. The breakaway on our RX7 was set to around 75 ft-lb and I felt like that was a little too slippy and hard to predict on corner exit sometimes, although braking and turn-in were fantastic. The XR4Ti's LSD is 200ft-lbs+ and needs to be beaten into submission (or a yank of the handbrake) to get it to start turning... but then again, the car is sort of a pig and was actually worse on turn-in with an open diff.
Certainly possible, though i don't hear from other e30 rally/ralycross guys with 6cyl engines that they have killed the diffs at any significant rate. I managed to chew up my small-case 3.91 LSD after 5-6 years, but that was literally original to the car so 30 years old......
I've never had turn-in problems with a stock-lockup e30 diff of any kind.
Things I hate: anything that requires messing with the trailing arms...
I really want to thank the designers at BMW for their thoughtless design that for some reason put the fuel filler right in the way of removing one of the trailing arm bolts - necessitating removal of the filler hose. This isn't that hard, but if you have more than half a tank of gasoline in the tank, you're gonna have to drain it or spill it (I did plenty of both).
I mean, would it have really been that hard to move it over toward the center of the car a few inches??
Anyhow, trailing arm #2 off, and the reinforced one on (with new bearings, new brake pads, etc).
While in there, I dropped the 4.10 diff out
And put the 3.73 in, for better gearing for rallycross (I will still use the 4.10 for stage, I think)
Note: the dog was no help at all...
A look back at the plated trailing arms and some of the car's underbody protection
Also started getting the new skidplate fitted, but got tired of working on the car and called it a day, so will finish that up later.
I remember saying to myself when working on the E30, "it's like this car was designed by teams of talented engineers who never talked to each other..."
Ian F said:I remember saying to myself when working on the E30, "it's like this car was designed by teams of talented engineers who never talked to each other..."
I'll be honest - I have a brand-new gas tank to put in at some point this summer. I'm seriously considering cutting and patching the stock inlet pipe and welding a new one on 3-4" farther over just to avoid this issue again. Since the tank has never had gasoline in it, it's probably the one and only time I could do something like this.
In reply to irish44j :
Maybe cut out an oval including the fill port, rotate 180 and re-weld?
My guess is the FSM method for removing the trailing arms is to drop the sub-frame, which is probably why the issue you're running into would never occur to the designers.
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