BMW M5 Forum and M6 Forums banner
1 - 8 of 8 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter · #1 ·
Hi Everyone!

First of all i want to introduce myself:

My name is Nikola. I live in Hungary. I was 7 when my father has an e34 525i with full m-packet on it. I fell in love with that car and decided when i grow up i will have a real E34 M5. And my dreams come true last summer so iam happy owner. I can't describe by words what i feel when i drive my car, but i think all of the e34 M5 owners are feel the same :) I use my car for everyday use and i could say that once a week i push it realy hard. (maybe someone doesn't agree with me but i think an M should drive like a racecar sometimes)

For this summer i decided to upgrade my car a bit:
I realy like the original suspension, so i don't want to change it, but i want to lower a car a bit. What do you think if i buy a new spring set would it change the car behavior?

I plan to bring the car for a remap, or by a chip. Do you have experience about it? I don't have big requirements just i want to make may car a bit faster.

Thank you in advance and sorry for my bad english :)
 

·
Registered
Joined
·
497 Posts
Hi Nick,

Welcome to the forum,
My personal advice. Do NOT lower the car. It's low enough for fast driving. I would spend my money on replacing the bits and pieces that need to be replaced. To name a few:
1) Chain tensioner > A no brainer to me:)
2) all the tubing on the inlet side
3) EDC if you still have it:)
4) Suspension bushings
5) Disks and tyres
6) Valve clearances
7) Throttle bodies (TPS) and all the inlet seals.

Unless you're sure all the above is already recently done and/or in mint condition I wouldn't consider lowering the car unless you're seeking for an early meltdown.......

Hope this helps:)
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #3 ·
Thank you for your reply.

My car i in mint condition. I did everything you wrote + i change the waterpump + wisco to an original new one.
The reason why i want to lower my car is just for me it looks better lower, but if you said it will kill the geometry of the original suspension i will not make it.

In the future i plan to buy a 6 speed gearbox if it possible. Do anyone tried to match the S38b36 enginge with the s38b638 6 manual?
 

·
Registered
Joined
·
7,677 Posts
Welcome to the forum Nick and congratulations on fulfilling your dream !

You can fit the 6 speed E34 M5 Box directly to your S38B36 , although you will need the shorter 6 speed prop .

D
 

·
Registered
Joined
·
508 Posts
Welcome to the fourms Nick. I pretty much did just as you did and recently purchased oe of the cars i dreamed about as a kid.

Anyways, i am in the process of replacing all the suspension bushings and rubber + lower the car with H&R springs and Koni Sport Yellow shock inserts. I have driven the car with the old SLS system in it rides like **** especially in the back because the SLS is not working properly and it is bouncy. To worsen the problem, all the bushings needed changing and tierods were loose. So after I change all of this which shouldnt take more than a 1-2weeks, time depending, I can let you know how it rides.

I can tell you that I had a VW GTI MK2 1.8v with Neuspeed race springs and Koni Sport shocks and new rubber bushings and steering componenets. It handled like a dream. If you want to have a really aggressive ride, I would suggest it just based on the past experience. However, if your roads are bad I would not suggest this suspension. Additionally, I would strongly suggest you change the struts/shocks with bilstein or koni unless done so recently.

On another note, does the chain tensioner have to be changed or replaced? I mean is there an interval at which it is good practice to change it? I didn't even think about replacing this...should I?

*Forgot to say that I had mine the first time with the installed Tunermotorsports Chip and like it. I think it is well worth the money.
 

·
Registered
Joined
·
65 Posts
When I bought my car it was equipped with a full Stage III Dinan suspension package, sway bars, lowering springs, camber plates... and it drove like a dream on smooth flat roads. But on back roads where there are ruts it was all over the road. So I pulled the springs, lowered it to the bump stops and raised it one cm at a time carefully measuring toe and camber at all four wheels. I learned two things:

1) It is worth making sure the steering box is properly centered. Often the mechanic will align the front by adjusting only one side and as you go over bumps the front toe changes differently on each side. Also, this introduces extra play in the steering as play is minimum when the box is centered.

2) The BMW engineers knew what they were doing when they set the ride height. Any lower than stock and there are dramatic changes in rear camber as the suspension moves due to the semi-trailing arm design. I understand lowering the car for better looks or for a pure track car (in which case very stiff springs are in order) but for a street driven car that you want to perform at the highest level, keep the stock springs.

I switched to stock springs, Dinan front sway bar, M-Touring rear bar, kept the front camber plates and added adjustible bushings in the rear trailing arms to minimize rear camber. I can't say enough good things about this combination. The twitchy behavior is gone. Understeer is greatly reduced to to increased rear roll stiffness reduced rear camber.

The other thing that helped was going to factory offset wheels and tires - same size front and rear.
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #7 ·
Thank you for your replies.

I think i will keep the original suspension till it become bad. If anything needs to be changed i'll buy a koni set for myself. I think it will worth a try.

I also try the Tunermotorsport Chip what you suggest Stija, because i hope it will give me that little powergain what i looking for.

After i did that i will upload the results, before the chip and after install it.

I will upload a few pics soon.
 

·
Registered
Joined
·
2,890 Posts
In the future i plan to buy a 6 speed gearbox if it possible. Do anyone tried to match the S38b36 enginge with the s38b638 6 manual?
You must also change the diff,, it would be to low geared imo in 1.2.3.4

have a look.........


6-speed and differential upgrade

Conversion done by Brett Anderson of KoalaMotosport
web: Koala Motorsport Home e-mail: [email protected]

All '89-'94 M5s were equipped with the Getrag 280 gearbox. This is a good, robust gearbox that follows it's lineage back through the E28 M5's virtually identical 280, and the 265 and 260 used in the 535i, 533i, and 6-series variants. Despite a propensity to get a bit "crunchy" in 2nd gear, it can take a lot more power transmitted through it that BMW ever supplied. The 280 in my 475hp E28 M5 Turbo felt as good at 35K miles as any brand-new unit.

The differentials in M5s varied by market. '89-'94 cars sold outside of the USA had the 3.91 limited slip differential. This diff, coupled with the 5-speed's gear ratios, provided a good spread in ratios and reasonable highway cruising.

In the USA, only the '91 cars had the 3.91. Apparently for fuel economy reasons, the 3.73 gearset was used in the '92-'93 cars. Why "fuel economy" was a factor in the country that has almost the lowest gas prices in the world is a bit of a mystery.

In 1995, the last year of E34 production, BMW fitted the Getrag G420 6-speed transmission to the M5. The gear ratios are completely different than the 5-speed 280, and the differential gearset was changed to the 3.23 to take advantage of the change. Instead of installing a close-ratio box, the net effect of the 6-speed/3.23 combo is simply an additional overdrive gear. 1st-5th are basically the same as the 5-speed/3.91 combo, and the 6th allows low-rpm cruising. A performance change? No. This was done strictly for fuel economy as well.

Nevertheless, this does not preclude the possibility of re-configuring a few parts to create the best of both performance and economy worlds; enter the 6-speed and either 3.45 or 3.64 combination. These are not common gearsets, the 3.45 comes from various older 7-series models and the 3.64 from the 8-series. Thes gearsets are completely compatible with the M5's differential housing.

I originally used the 3.45, but eventually change to the 3.64. First, compare the numbers for the factory combinations and my combinations:



5-speed
with 3.73 TRANS
& DIFF GEAR OVERALL
GEAR MPH @
3000 RPM MPH @
7250 RPM
1st 3.51 13.09 17 40
2nd 2.08 7.76 28 68
3rd 1.35 5.04 44 105
4th 1 3.73 59 142
5th 0.81 3.02 73


5-speed
with 3.91 TRANS
& DIFF GEAR OVERALL
GEAR MPH @
3000 RPM MPH @
7250 RPM
1st 3.51 13.72 16 39
2nd 2.08 8.13 27 65
3rd 1.35 5.28 42 100
4th 1 3.91 56 135
5th 0.81 3.17 69 167

6-speed
with 3.23 TRANS
& DIFF GEAR OVERALL
GEAR MPH @
3000 RPM MPH @
7250 RPM
1st 4.23 13.66 16 39
2nd 2.53 8.17 27 65
3rd 1.67 5.39 41 99
4th 1.23 3.97 56 135
5th 1 3.23 69 166
6th 0.83 2.68 83 200

6-speed
with 3.45 TRANS
& DIFF GEAR OVERALL
GEAR MPH @
3000 RPM MPH @
7250 RPM
1st 4.23 14.59 15 37
2nd 2.53 8.73 25 61
3rd 1.67 5.76 38 93
4th 1.23 4.24 52 126
5th 1 3.45 64 155
6th 0.83 2.86 77 187

As shown, the original equipment setup for the 6-speed/3.23 is effectively the same as my car's original 5-speed/3.91 combination. By building a diff with the 3.45 gearset, the effective result is a 7% lower 1st-5th gears and 6th gear taller than the original 5th by about 10%.

The results are excellent for most needs. Acceleration is quicker without having to abuse the clutch, and cruising rpm is noticeably reduced. 80mph in 6th gear is 3,000rpm... very relaxed, yet the 3.8l motor has enough p
 
1 - 8 of 8 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top