Construction Zone
Don\
Welcome! Log In Register

Advanced

BMW test build

Posted by NoCoast 
Forum List Topic List Start New Topic
Page 3 of 5    Pages: Previous12345Next
Newer Topic Older Topic
DaveK
Dave Kern
Godlike Moderator
Location: Centennial
Join Date: 07/11/2008
Age: Midlife Crisis
Posts: 1,085

Rally Car:
Compact M3 & Evo IX
DaveK
Re: BMW test build
January 09, 2013 12:55PM
Quote
aj_johnson
Go take a spin in one, as a street car the new turbo 135 or whatever it is, is an absolutely stupid fun car, I can only imagine what the M would be like, but if I had the disposable income I'd love to have one as a daily driver.

I worked a BMW program last summer where I got to drive/hoon the V8 M3 and several 335 cars (some auto, some manual). Loved the power delivery and that little "woomph" from the exhaust pipe of the turbo cars on upshifts, but can't imagine spending that kind of money on a car to get to work and back. My current daily driver is a $3k beater legacy wagon with a JDM swapped EJ20...probably spent too much on that and certainly spent too much time on it.

Big issue to be aware of on the earlier model 335s is that they had lots of problems with the fuel delivery system.

Dave
Please Login or Register to post a reply
phlat65
Sean Medcroft
Ultra Moderator
Location: Edmonds, Washington
Join Date: 02/12/2009
Age: Possibly Wise
Posts: 1,802

Rally Car:
Building a Merkur
phlat65
Re: BMW test build
January 09, 2013 01:58PM
Dave, Derik's E36 M3 came in under 2500lbs on street tires with no spare and tools. Something like 2460, so there is plenty of weight to remove.

Quote
DaveK
Quote
Wannabe
I've driven BMWs for many years now, albeit not in a rally but definitely testing the limits on the cars I've owned. So the one thing that's great about BMWs and not great about BMWs is their weight. I've read through this thread and not really clear if you are planning on using a different body or BMW everything? (I know in rally the weight of every little piece makes a difference winking smiley ). You should go out and test drive a 1 series if you haven't yet. I'm sure you know this but they put the old M3 engine in a smaller lighter frame and its a blast to drive. They revamped the all the M series engines a few years ago.

While 1 series would be fun, I'd guess its still a heavier car than the E36, just with the march of technology and all the extra crap that gets added to newer vehicles. The other problem with the 1 series is cost. Old 3-series can be found running with a few issues (bad window regulators, broken sunroof) for about $1000.

Second, BMWs tend to have loads of crap in them that gets removed during the rally preparation process. A "luxury car" is going to have much more weight that's removeable as compared to say an Evo, where the whole interior was designed to be somewhat light. In the BMW the carpet is heavy, seats are heavy, knee protection under the dash is heavy, sound deadening is everywhere, rubberized coating on the underside is gooped on thick and so on and so forth. For a quick/cheap build, only some of these items will be addressed though.

Third thing to consider is that if you were building a Group 2 car, a 3.0L engine has a minimum weight of 2535 lbs. My Compact started life at 2820 with a little gas in the tank. Its now at about 2650 lbs (though missing spare tire, tool kit, spill kit that would be added at rally time) but other than that about ready to race. There are commercially available bits to order that should easily drop 100 lbs from the car. Here's weights on a few items that can be swapped:

Front Bumper 27 lbs (skin, crash beam, & mounts)
Other Front Brackets 16 lbs (brace, top of bumper, not including lights)
Hood 38 lbs (as removed from car, sound deadening still attached)
Front Fender 7.5 lbs
Dash Assembly 17 lbs (still had a few vent peices attached to bottom)
Rear 1/4 Windows 7 lbs (seal still attached to glass)
Rear Bumper Assembly 30 lbs (skin, beam, & mounts)
Hatch 46 lbs (hatch, glass, both struts)


Dave
Please Login or Register to post a reply
NoCoast
Grant Hughes
Senior Moderator
Location: Whitefish, MT
Join Date: 01/11/2006
Age: Midlife Crisis
Posts: 6,818

Rally Car:
BMW
NoCoast
Re: BMW test build
January 09, 2013 02:32PM
Okay, here's some pictures...





Disassembled diff:






A little short on plates. Belleville washer, steel disc, and friction plate. That's it on this side. Didn't dig in to see if other side is the same.




45 degree ramp angles on accel and decel.


Obligatory Merkur photo...



Grant Hughes
Please Login or Register to post a reply
john vanlandingham
John Vanlandingham
Junior Moderator
Location: Ford Asylum, Sleezattle, WA
Join Date: 12/20/2005
Age: Fossilized
Posts: 14,152

Rally Car:
Saab 96 V4
john vanlandingham
Re: BMW test build
January 09, 2013 03:02PM
Grantie-poo dahrlink, this is your chance to set the diff pre-load and stack the plates for max grip..
There should be a small washer in a recess that you can swap or add shims under, maybe 020" and up the breakaway torque..

You familiar how to do this?

If you're going to be fucking with these things you oughtter get an extra output flange thang and weld a bug 1" or 1 1/4" nut into the middle , then you have sumpin to put the torque wrench on when checking break away..

You know what I'm talking about?


John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.



Edited 1 time(s). Last edit at 01/09/2013 03:02PM by john vanlandingham.
Please Login or Register to post a reply
NoCoast
Grant Hughes
Senior Moderator
Location: Whitefish, MT
Join Date: 01/11/2006
Age: Midlife Crisis
Posts: 6,818

Rally Car:
BMW
NoCoast
Re: BMW test build
January 09, 2013 03:16PM
Yes. There was a little shim under there already. So adding shims there will increase the preload by increasing pressure on the outer ring of the Belleville right?
I'll have at least two extra output shafts so will weld on a nut ASAP.

What's thought on modifying ramp angles to get less lock on decel?


Grant Hughes
Please Login or Register to post a reply
DaveK
Dave Kern
Godlike Moderator
Location: Centennial
Join Date: 07/11/2008
Age: Midlife Crisis
Posts: 1,085

Rally Car:
Compact M3 & Evo IX
DaveK
Re: BMW test build
January 09, 2013 03:19PM
Forget shims...is there room to add more plates?

I think guys cut down the shims and add more plates with the Evo diff so they go from 6 to 8 plates.
Please Login or Register to post a reply
NoCoast
Grant Hughes
Senior Moderator
Location: Whitefish, MT
Join Date: 01/11/2006
Age: Midlife Crisis
Posts: 6,818

Rally Car:
BMW
NoCoast
Re: BMW test build
January 09, 2013 03:49PM
Quote
DaveK
Forget shims...is there room to add more plates?

I think guys cut down the shims and add more plates with the Evo diff so they go from 6 to 8 plates.

No, but you could machine the top plate down a bit to fit more plates in. If I'm lucky the 4.10 diff I'm grabbing tomorrow will also be a LSD one and we can entertain that possibly...

What would be the benefit of more plates?


Grant Hughes
Please Login or Register to post a reply
DaveK
Dave Kern
Godlike Moderator
Location: Centennial
Join Date: 07/11/2008
Age: Midlife Crisis
Posts: 1,085

Rally Car:
Compact M3 & Evo IX
DaveK
Re: BMW test build
January 09, 2013 03:55PM
Quote
NoCoast
What would be the benefit of more plates?

More surface area over which to spread the locking. I think that helps with operating temperatures and probably longevity, may also allow you to have it lock harder, but not sure if that last one is something we need offroad.
Please Login or Register to post a reply
NoCoast
Grant Hughes
Senior Moderator
Location: Whitefish, MT
Join Date: 01/11/2006
Age: Midlife Crisis
Posts: 6,818

Rally Car:
BMW
NoCoast
Re: BMW test build
January 09, 2013 04:08PM
Some other research indicates they "might" be the same as Porsche diffs internally? Emailed our local Porsche differential specialist to see if he knows anything about that. Also to see if he can supply plates. Not sure how to assess the quality or need for replacement of the plates in the diff either.


Grant Hughes
Please Login or Register to post a reply
DaveK
Dave Kern
Godlike Moderator
Location: Centennial
Join Date: 07/11/2008
Age: Midlife Crisis
Posts: 1,085

Rally Car:
Compact M3 & Evo IX
DaveK
Re: BMW test build
January 09, 2013 04:10PM
Quote
NoCoast
Not sure how to assess the quality or need for replacement of the plates in the diff either.

This is similar to the duct tape/WD-40 flow chart:



Does it leave 2 stripes....beer.
Does it leave 1 stripe...fix.
Please Login or Register to post a reply
danster
Haggis Muncher
Ultra Moderator
Location: Haggisland UK
Join Date: 01/04/2013
Age: Possibly Wise
Posts: 409

Rally Car:
VWs (for my sins)
danster
Re: BMW test build
January 09, 2013 04:28PM
Quote
DaveK
Does it leave 2 stripes....beer.
Does it leave 1 stripe...fix.

^^^ thumbs up smileys with beer

You could always ask Patrick Snijers to test the diffs for you. He certainly is a man who could chuck a BMW around. Check him out laying down the rubber as he test his diff! In fact the kid in the other thread who trashed his daddy's M3 was probably trying to emulate the master himself... (and failing).





Disappointingly not yet a Jackass



Edited 1 time(s). Last edit at 01/09/2013 05:08PM by danster.
Please Login or Register to post a reply
NoCoast
Grant Hughes
Senior Moderator
Location: Whitefish, MT
Join Date: 01/11/2006
Age: Midlife Crisis
Posts: 6,818

Rally Car:
BMW
NoCoast
Re: BMW test build
January 09, 2013 06:03PM
E30 and tarmac. yawn... smiling smiley

Just met the guy with the quicker and linear Z3 rack. So I got that now also. The stock rack is progressive and slower ratio. Increase of about 40% with the Z3 rack and got it for pretty cheap AND the guy delivered it to me. Sweet.
Gonna take the diff up to a friend who's company makes Porsche diffs and gearsets once I get the ring and pinion I want to use. Hopefully next week sometime. Will post pictures of course. Hopeful we can get a few more plates in and test breakaway and get a decent setup worked out.


Grant Hughes
Please Login or Register to post a reply
danster
Haggis Muncher
Ultra Moderator
Location: Haggisland UK
Join Date: 01/04/2013
Age: Possibly Wise
Posts: 409

Rally Car:
VWs (for my sins)
danster
Re: BMW test build
January 10, 2013 05:22AM
I did find a great 15 minute vid of BMWs on both gravel and tarmac but thought it a bit long to post. Just wanted to show a diff working.

I have been reading up on the few BMW topics and threads on here and it certainly makes me think there is a lot of potetinal in them. We have plenty E36 including compacts over here available for very little money. In fact even the later E46 are now turning up for around a 1000GBP.
When I look at the older mk1 & 2 VW platforms I muck around with and compare them to the more modern cars I really see how the strength of the shells has improved. This has got to be a major safety consideration.
I pulled some panels off a mk4 golf last year and behind the outer sills it was incredible to see the way it was put together and how strong it was. I'll presume BMWs of that era are pretty much the same as they were all passing similar crash tests.
And I would go as far as to say that a mk1 golf with a basic cage might just be as strong as a mk4 golf without one.


Disappointingly not yet a Jackass
Please Login or Register to post a reply
john vanlandingham
John Vanlandingham
Junior Moderator
Location: Ford Asylum, Sleezattle, WA
Join Date: 12/20/2005
Age: Fossilized
Posts: 14,152

Rally Car:
Saab 96 V4
john vanlandingham
Re: BMW test build
January 10, 2013 09:55AM
Danny, modern shells are strong in just exactly the way the need to be for the US DOT or EU crash tests..

Years ago I was reading a German mag about this and the figures ---Germans really do love figures----showed yep if you smack a car into a solid concrete wall exactly square, at 50km/hr---31 (English) mph for youse 9duddn't that piss ya off that you have to use ENGlish miles?) ---everything is just marvelous

But figures show cars hitting things at a slight offset were killing the drivers even in big supposedly best safe cars like big Mercedes, big Bee Em, big Lexus, all full of airbags etc..

Modern CAD with FEA capability alows designers to make stuff "strong enough" in the intended usage and that means a car driving straight ahead going to get groceries..
An excellent example is the Frod Fuckus rear suspension. OK to go straight down the road. pure unadulterated ka-ka against any side loading.

Wanna see piccies to illustrate?


John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.
Please Login or Register to post a reply
DaveK
Dave Kern
Godlike Moderator
Location: Centennial
Join Date: 07/11/2008
Age: Midlife Crisis
Posts: 1,085

Rally Car:
Compact M3 & Evo IX
DaveK
Re: BMW test build
January 10, 2013 10:03AM
^ Probably why most cars are designed to understeer into things! Hell, even traction control systems are trying to keep the damn things headed straight and ruin all the fun.

Dave
Please Login or Register to post a reply
Page 3 of 5    Pages: Previous12345Next
Newer Topic Older Topic
Forum List Topic List Start New Topic
Sorry, only registered users may post in this forum.

Click here to login