irish44j Josh Hickey Junior Moderator Location: Northern Virginia Join Date: 05/25/2016 Age: Midlife Crisis Posts: 13 Rally Car: 1985 BMW 318i (M42) |
FWIW I've been very happy with the four sets of DMack DMG3's I've owned. Less happy with the Yokos and Hankooks. I hear the Dmacks in 15" size are a BITCH to mount though (14" DMacks are pretty easy though) |
formyhealth Danny Maxwell Senior Moderator Location: Oregon Join Date: 05/24/2016 Age: Settling Down Posts: 60 Rally Car: 1991 BMW 318is |
Do you have one of those harbor freight jobbies for debeading/mounting tires? Or do you just use a few bars? Those DMACKs are a pretty good price, are you running softs or hards? I was interested in the maxsport rb3s as they are ~$88 a piece so I could get 8 of them for about $150 more than a set of 4 of the DMACKs. |
irish44j Josh Hickey Junior Moderator Location: Northern Virginia Join Date: 05/25/2016 Age: Midlife Crisis Posts: 13 Rally Car: 1985 BMW 318i (M42) |
I have a friend who I rallycross with who has proper tire machines in his basement and does all my tires. I would think it woudl be nearly impossible to mount gravels just using bars. I run medium compounds on the DMacks usually but have a couple softs as well. Depends on the temperatures/surfaces of your local venue. In Oregon you guys are probably on cooler dirt/mud so softs may be preferable. Also Maxsports are retreads. Some guys local use them for rallycross and they're fine (though apparently a lot softer sidewalls than most other gravel tires), but I woudln't use them for stage rally. |
formyhealth Danny Maxwell Senior Moderator Location: Oregon Join Date: 05/24/2016 Age: Settling Down Posts: 60 Rally Car: 1991 BMW 318is |
Dang, lucky dude it'd be nice to have a friend like that. Thanks again for the advice, retreads would probably be cool with me for practice and such, trying to keep the price down for now because I'm new to the sport and am trying not to dive in head first like I do with all my other hobbies (which are now on the back burner) |
NoCoast Grant Hughes Elite Moderator Location: Whitefish, MT Join Date: 01/11/2006 Age: Midlife Crisis Posts: 6,818 Rally Car: BMW |
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formyhealth Danny Maxwell Senior Moderator Location: Oregon Join Date: 05/24/2016 Age: Settling Down Posts: 60 Rally Car: 1991 BMW 318is |
I feel like I can stay in 2nd for most of it because of how short the 318is gearing is. I'll have to go out and give it a go before I decide what will be best. |
Nate.Vincent Nate Vincent Ultra Moderator Location: Pomfret, Ct Join Date: 07/29/2014 Age: Settling Down Posts: 29 Rally Car: BMW 318ti |
In that case (no pun intended) I may keep the small case 4:44 diff. I'm running that exact engine set up and was planning on keeping it as a spare, but if it held up in his car it should hold up in mine. Was Kern's differential modded at all or left alone? |
formyhealth Danny Maxwell Senior Moderator Location: Oregon Join Date: 05/24/2016 Age: Settling Down Posts: 60 Rally Car: 1991 BMW 318is |
Or, or, or, you could sell it to me! |
formyhealth Danny Maxwell Senior Moderator Location: Oregon Join Date: 05/24/2016 Age: Settling Down Posts: 60 Rally Car: 1991 BMW 318is |
So my uncle called me today, he is having problems with his 1998 528i wagon and just wants to get it out of his garage, so it looks like I'll have 2 wagons now.
decided I'll keep it, it's a nice color! Exciting! Edited 1 time(s). Last edit at 05/29/2016 02:11AM by formyhealth. |
irish44j Josh Hickey Junior Moderator Location: Northern Virginia Join Date: 05/25/2016 Age: Midlife Crisis Posts: 13 Rally Car: 1985 BMW 318i (M42) |
You guys must have some slow/tight courses. A 2.93 with a G240/M42 at our events would result in constant 1-2 shifts throughout the course and being below the torque curve in 2nd, it seems to me. Then again, my car routinely hits 60ish a couple times per run on our courses. Our course designers are stage guys, so they like to keep it pretty open Hmm....I have an open 2.xx out in the shed. Maybe if I'm bored I'll throw that into the car and see for sure at a test&tune or something.... Edited 1 time(s). Last edit at 05/27/2016 08:14PM by irish44j. |
paperpaper Dan Downey Infallible Moderator Location: Franklin, MA Join Date: 02/24/2014 Age: Settling Down Posts: 28 Rally Car: e30 |
For Rallyx it all depends on the course. until he knows how fast he can go on course he has no idea what ratio is best. For stage lower is better. Especially with our retarded 3rd gears. Given money, time, and guarantee that I would trailer my car to every event, I would buy that ring gear for 5.44 in an instant. AFAIK both medium and small case Diffs are 25% locking from the factory. nothing to loose/gain there. The Med case is certainly not 40% stock. Says so on my fancy Germany delivery sheet. Both are build-able for more. 4.10's are readily available in both small and medium form near me. not sure if you live in black out zone. As I said before for Rallyx you will have no idea what gearing you need until you try the course and find out how fast your car(and you) can push it on the straits. But any where from 3.73 to 4.10 should be easy to find. |
formyhealth Danny Maxwell Senior Moderator Location: Oregon Join Date: 05/24/2016 Age: Settling Down Posts: 60 Rally Car: 1991 BMW 318is |
You're not wrong! I am having a difficult time locating an lsd variant of the small case differential here in Oregon. I've tried a used part search website with no luck, I have found some on Ebay but who knows really? I'm still looking though, I figure a 4.10 would be fine for me as of now, and then can and will change the ratio when changing venues. |
NoCoast Grant Hughes Elite Moderator Location: Whitefish, MT Join Date: 01/11/2006 Age: Midlife Crisis Posts: 6,818 Rally Car: BMW |
Its rallycross, run whatever ratio comes with the diff.
Ironically I was reading an article today about Xtrac devising and building a test rig for mevhanical differentials, which until then were essentially untestable aside from on track/road. A 20% diff from an M3 could be a 40% diff in a M42 engined car.... Grant Hughes |
irish44j Josh Hickey Junior Moderator Location: Northern Virginia Join Date: 05/25/2016 Age: Midlife Crisis Posts: 13 Rally Car: 1985 BMW 318i (M42) |
FYI also depends on which G240 he has. The early G240 actually has longer gearing 1-3 than the G260 in your 325. The late 318is G240 has a longer 1-2, but a much shorter 3rd (1.61 vs. 1.40). As to the diffs, I certainly could be mistaken, but I've been told that by Jon Thayer (who basically rebuilds BMW diffs nonstop) and also (IIRC) by someone from Metric Mechanic. I have two totally rebuilt diffs here (3.91 small case and 3.73 medium), both rebuilt to stock spec with OEM parts. The ratios are not very different in reality, but in terms of on-course feel the 3.73 most certainly *feels* like it has substantially more lockup. Could be butt-dyno, but I know this car pretty damn well. One would think with larger clutches in the medium case, it would have more lockup - that seems logical. But I don't know if the ramp angles are the same, so..... As to small vs. medium, there are things to "lose and gain." The small case is substantially lighter (I have swapped them back and forth many times, I know it well). The medium case has a spacer in it allowing for a third clutch pack to be installed for additional lockup with no modifications to the case. The small case does not, so you're stuck with two clutch packs no matter what. You can increase lock a bit using the Porsche clutch packs and different preload, but that's fairly mnimal. Edited 1 time(s). Last edit at 05/31/2016 04:20PM by irish44j. |
paperpaper Dan Downey Infallible Moderator Location: Franklin, MA Join Date: 02/24/2014 Age: Settling Down Posts: 28 Rally Car: e30 |
All i know is BMW claimed 25% from factory with Med case so take that gray space as you will. Certainly a third plate will yeald more ( especially when you mess something up and the diff binds to full welded lol). All I have is form info so all grain of salt.
Really for Rallyx run what ya got as long as it is LSD. hell weld a open one. smooth is fast and the rest is just bullshit talk anyways. as long as you got both wheels pushing forward you have got it made. Join your local e30 FB pages and scrounge the junkers. you will find something. I know that pacific northwest has huge e30 following. respect your elders is filmed out there. along with the e30 picnic. just as long as you beat the xraty's. |