E30 Rally Build Thread

[MasterOfPuppets]

Just drove the E30 to work after lunch. On the way, was cruising along at ~45 mph and heard a "ping" in the roof vent directly above my face. Turns out it was a giant wasp/bee of some kind, and if my vents didn't have the grating on the inside, it would have bounced directly into my face. Moral of the story, make sure there's grating on your roof vents.

[iamsam]

I still can't believe that you are going to paint up these wheels.... I dunno, it might grow on me, kind of like your orange and blue grills did.

[MasterOfPuppets]

Advice on cage, we built our first one and paid for the rest. Find a shop who does Rally builds and get to know the owner. They will build a cage that follows the car and tie it in properly. You as a driver want as much room as you can get around you. Elbows and ankles hitting bars hurt...

Thanks for signing up to post... I have just one question: Do elbows and ankles hitting bars hurt more than the price tag of a pro cage build? Because that hurts a lot... :mrgreen:

But seriously, good points... and the firehose o' gravel will be a good image to consider as I shield up the underside of the car this winter.

Just want to chime in with the gears - the reverse on my 260 really has to be pushed left with a fair amount of force and I've never been afraid of accidentally engaging it.
Not sure if/what has been done to it.

Hmmm... wonder if mine's just really tired. I still do it when I drive the car now even after not having the Z06 for a few months. I think a reverse lockout bar will have to be implemented.

In other news, as soon as the USG gets off their collective ass and pays me for my move, I'll be ordering wheels and tires for the car. As a sanity check, here are my wheel and tire choices:

Wheels: TRM C1 15x7" +25mm offset:



Tires: Lassa Rally 3 195/65R15



The wheels will get painted two orange, two blue to help keep the directional sides separate (and to help with the crazed look). Total cost for the wheels and tires (four each) shipped will be just over $1100. Yes, I know I will want more later for spares, but for now I just need to cram them on the car to see how they fit and gauge the need for a suspension lift.

[Fusion]

Just want to chime in with the gears - the reverse on my 260 really has to be pushed left with a fair amount of force and I've never been afraid of accidentally engaging it.
Not sure if/what has been done to it.
Nice build. I would love to build a car like this.

[difuser]

A little late to the replies but the HDPE skidding is great advice but I would say to use full length sheets down each side with a small Alum/ Steel plate as a diverter for all the roost off the front wheels at your exhaust. Over time the leading pipe will easily get ovalled.
We use it on our RS in 2-3 overlapping sections. I also did the same with my old AE86 Corolla.

Think of the underside of your car getting a firehose filled with gravel aimed at it and anything square you will want to have some sort of skidding or?? to divert that blast.

The build looks great so far. Your camera mount when you get to any kind of official scrutineering will be vetoed quickly.

Advice on cage, we built our first one and paid for the rest. Find a shop who does Rally builds and get to know the owner. They will build a cage that follows the car and tie it in properly. You as a driver want as much room as you can get around you. Elbows and ankles hitting bars hurt...
If you are not involved locally now get on with a team to learn the ins and outs and people who can help you $$$ reducing your cost because you know them. You will also understand the ebb and flow of a day competing alot better than walking in blind. It can be very crazy your first Rally or 2.

Good luck, I've built 4 Stage legal cars and it was a blast but also can be frustrating getting the last details nailed down. I've been away the last 6-7yrs and was very suprised how much they have changed the rulebook with cage design and construction.

I'm looking for a decent E30 for my wife to use as a RallyX car. She got a ride last weekend in the RS at a local event and is hooked now....

[Frog]

I can't seem to find it in the thread, but can you tell me what you used to cover your dash?

[MasterOfPuppets]

That sucks. I had no idea that it would fail anytime soon.

What about taking the clutch packs from the stock 3.73 LSD and putting them in the 4.10 LSD? Or go the other route, take the gears from the 4.10 and put them in the 3.73? The 3.73 will have the lowest mileage. It might require re-shimming... You could take the diffs to a transmission shop and they might be able to do the swap for you.

Of course there is always the quaife option ($$$).

Yeah, it seemed fine when I bought it. No odd noises, and it definetely functioned then. Is what it is.

Good idea on the parts swappage... I'll have to dig into how hard that is. Most likely, I won't have time to touch it before my 1600mi trek up to MI, at which point it will only be driven for shakedown purposes and so fooling around with diffs becomes easier. We'll see.

[rstraugh]

1.) Within five minutes of starting to rally, the LSD was no longer L. No idea what caused it, and it still works fine as a one-wheel-wonder, but slip is no longer limited. Pretty irritating, really, since one of the main reasons I bought this particular car was for the 4.10 LSD... oh well. I'm debating welding one up and going locked to remove any concern for reliability... we'll see.

That sucks. I had no idea that it would fail anytime soon.

What about taking the clutch packs from the stock 3.73 LSD and putting them in the 4.10 LSD? Or go the other route, take the gears from the 4.10 and put them in the 3.73? The 3.73 will have the lowest mileage. It might require re-shimming... You could take the diffs to a transmission shop and they might be able to do the swap for you.

Of course there is always the quaife option ($$$).

[MasterOfPuppets]

HDPE is awesome stuff.

Where to buy?

[SlapDash]

What's a good pliable thickness on the HDPE sheets?

That was some seriously muddy E30. Nice work!

[KennyT]

A 270K transmission definitely explains things. I'm more used to the pair of 120k G260's I have and the 60k Roadster box. You could crack open that transmission and replace the 1st and 5th alignment springs with new/stronger.

You will want to protect anything important (oil pan, fuel tanks, fuel crossover line, etc) with at least .250 Plate Aluminum. I wouldn't use steel for the sake of weight. Anything that just needs to be shielded from rocks and sand (swingarms, axles, subframe bolts, wheel wells, etc) should be protected by HDPE. At the first night of Oregon Trail my driver hit a dividing fence, trashed the front quarter panel, and chucked the wheel liner. I was able to reinstall that liner without any issue. HDPE is awesome stuff.

For the rest of the rest of the belly pan you don't need anything other than maybe spray on bedliner. The pan will be shiny after every race and you just respray it after patching the cracks and holes.

[MasterOfPuppets]

On the shifting topic: You are trying way too hard. Slow down so you can be smooth. You probably don't need to be heel-toe shifting either, most competitors just drive the transmission hard and replace the clutch as needed. An OEM capacity or slightly above would be fine. The reverse lockout is a bad idea as the transmission will rotate and may jam gears. Do you have a short throw shifter installed? A longer throw might do you well in this case.

Fender liners and underbody protection: HDPE is the answer. You will probably want to make panels to completely block off the engine bay from underneath.

Pedals/Floor: Skateboard grip tape. 3m stuff may be cheaper and available at Lowes, but the skate stuff should hold up better.

Thanks for the feedback! All points taken, but a few clarifications and follow ups:

I try to heel-toe not for clutch preservation but to avoid loss of rear wheel traction when the low gear engages and spins up the engine. I thought I could get away from it but ended up spinning pretty good a few times approaching turns. May be a technique issue but I figured it was an important part of rallying...

On the shifter itself - I find this happening even on the street, so it's not entirely a hurry-up-and-shift issue. And I try to keep telling myself "slow is smooth, smooth is fast..."

I don't fully understand the problem with the lockout, is your idea that the shifter will torque the trans around the pivot where it hits the proposed lockout bar? I really don't apply much pressure to the left, I think the spring in the trans/shifter is just a bit weak after 270k miles. But yeah, taking some time and concentrating a bit more on shifts would be better in this case.

And on HDPE... I guess it's better than steel from a weight point of view, but I'd much rather fly off the road and grind across rocks on a steel underbelly than plastic. I'll hit a few rallies and see what works for folks... I now have one vote in the "HDPE" column.

[KennyT]

On the shifting topic: You are trying way too hard. Slow down so you can be smooth. You probably don't need to be heel-toe shifting either, most competitors just drive the transmission hard and replace the clutch as needed. An OEM capacity or slightly above would be fine. The reverse lockout is a bad idea as the transmission will rotate and may jam gears. Do you have a short throw shifter installed? A longer throw might do you well in this case.

Fender liners and underbody protection: HDPE is the answer. You will probably want to make panels to completely block off the engine bay from underneath.

Pedals/Floor: Skateboard grip tape. 3m stuff may be cheaper and available at Lowes, but the skate stuff should hold up better.

[MasterOfPuppets]

Rally at CORE as a shakedown

So I took the car out to CORE for a day of rally practice and car test this weekend (full pic thread is here). From the car design point of view, I had a few objectives:

1.) Learn to rally the LSD/manual combo
2.) Evaluate the car's reliability
3.) Evaluate my mods to the car
4.) Identify potential improvements

The last time we were at CORE is was a dry dustfest, so that's what we were expecting this time. However, when we arrived, we found that much of the track was covered in puddles in all the wrong places (e.g. in a banked corner, the low part.) This meant that as soon as anyone hit a puddle and spread water over the width of the course, that corner became impassable. We got stuck several times and slid off the track many more. Probably a good experience in obstacle avoidance and bad conditions, but not good for someone focused on car control and finding the right line through a normal corner.

So, in the order of my objectives above -

1.) Within five minutes of starting to rally, the LSD was no longer L. No idea what caused it, and it still works fine as a one-wheel-wonder, but slip is no longer limited. Pretty irritating, really, since one of the main reasons I bought this particular car was for the 4.10 LSD... oh well. I'm debating welding one up and going locked to remove any concern for reliability... we'll see.

As for the manual, I did get good practice, especially heel-and-toeing, but since the clutch is veeery slippy it's hard to say if I'll be any good when I get a grippy clutch in. I at least got in the habit of getting my feet in the right position coming up to a turn.

I also found that the BMW shift pattern is my arch nemesis. In every other manual I've ever owned or driven, including my current Z06 DD, the shift pattern is something ending in "RUR," in this case "6RUR":



The E30 5-speed, though, is of course a "5UR-RUL." What this means to me: when I want to do a 3-2 downshift, which seems very common on a rally course, I basically yank the lever down and to the left with quite a bit of pressure to the left. On my Z06 especially, there's a good bit of L-R spring pressure to overcome to go into first or second from third or fourth, in fact almost as much as to put the E30 into reverse. So in the E30, when I attempt to do a 3-2 downshift, I pull down and left on the shifter which slides it into the reverse slot but obviously won't let it pull back since there's no gear there. This is especially apparent in any kind of bumpy situation since any kind of finesse with the shifter goes out the window. I probably did a 3-nothing heel-toed downshift hundreds of times on Saturday :curse:. Here's an example of an attempted 3-2 downshift, at :03 you can hear the throttle blip as I go for the heel-toe, then you can hear the engine revs fall off and then pick back up at :06 when I find second:



I'll fix this by simply putting a reverse lockout bar next to the shifter, so that when I pull left it hits the bar and stops in the 1-2 slot. The bar will of course be removable so that I can use reverse if need be, which will hopefully be rare in a rally stage...

Man, this is a long post...

2.) Other than the insta-fail LSD, the car proved extremely reliable. The only minor issue I had was the front plastic brush guard and fender liners all ripping off. I figure they would have been pulled anyways and replaced by suitably heavy-duty steel, but I definitely validated that reqt. The suspension took a pretty good flogging with no apparent negative effect (which was surprising, honestly).

3.) My mods all worked out great. The engine stayed cool even during extended flogging, no doubt in some small way due to the hood vent and AC removal. The roof vents were awesome and only pulled in mud if I really screwed up. The shift knob worked great. The hood pins worked despite being coated in mud. I never wore sunglasses the whole day and was never blinded by the sun's reflection off of dash or hood. And the Bilstein HDs handled everything I threw at them, including some air time:





4.) I came up with a long list of future mods to the car, especially if I ever have the need to race in mud again:

- Reverse lockout bar
- Mud flaps (required anyways)
- Grippy pedal surfaces
- Grippy floor surface beneath the pedals
- Supportive seats (I was running stocker non-sport seats)
- Much better wiper sprayers
- Bigger wiper fluid reservoir (maybe)
- Tires with tread
- Better underbody protection

I was pleasantly surprised by the performance of the suspension. While I will probably still go for a coilover conversion, this setup really isn't too bad. It absorbed everything CORE threw at it pretty well, which I can't imagine is too much smoother than an actual rally stage. Coilovers, another inch of ride height and an inch bigger tire and I'll call it good to go.

[MasterOfPuppets]

I almost built a rally e30 instead of my current track build. Only reason is that, surprisingly, in this dirt lovin redneck state, there is no rally sport in GA. Epic bu
Ild, thanks for sharing!

Get out there on the dirt oval with the sprint cars! I'm sure you could be competitive.

But seriously, sprint cars are badass.