GOD'S VENGEANCE - Complete Drivetrain Redux

Murfinator · Post by **Murfinator** » Jan 28, 2011 11:35 PM

mooseheadm5 wrote:Drool!

With boost you may find that you will have different desires for gear ratios and final drive ratio. Probably a good thing to keep the 265/6 for now.

That's what I'm thinking. Initially I was led to believe the CR was counterproductive with a turbo...then I met Paul. With his assistance this will one hell of a fun car to drive.

Corner Carver · Post by **Corner Carver** » Jan 29, 2011 1:02 AM

Murfinator wrote:
BBS RS 16x8et20,16x9et24

Do. Want.

shocka · Post by **shocka** » Jan 31, 2011 8:12 PM

Looks like your definitely doing things the right way the first time. Nice work, those Rs's are pure sex.

Black Steel · Post by **Black Steel** » Feb 01, 2011 5:30 AM

Murfinator wrote:I'll be installing the 265/5 CR box and keeping the OD as a spare. I won't be in first except in the pits. The CR also suits the driving I'll be doing on and off the track. Fifth being strong at 1:1 and will be perfect for the freeway when I need to pass without a downshift or want to do a run into the triple digits.

For wheels I'm trading off diameter for sidewall. I'll be able to put down more power to the ground with a taller sidewall on a 16" wheel than I will with a shorter sidewall on a 17" wheel. I'll also squeeze as big a contact patch as possible with a little bending and grinding. 275/45-16's sound about right.

Here's the wheels:

BBS RS 16x8et20,16x9et24

265 on the rear of an E28 is more than enough. To fit 275 you will have to do more than grinding & bending!
You will have to stretch the rear arches almost all the way up to the swage line!
Just fit some really sticky 265's. You will be able to keep the lines of the car intact then.

I am running staggered style 5's.
8 x 18" -- 225/40/18 on front & 9 x 18 -- 265/35/18 on the rear.

I'm running PZero corsa's all round.

With 235's on the front you are in danger of the inside of the tire coming in contact with the front anti roll bar on full lock with the suspension unloaded

Not good!

You could adjust your lock stops but do you really want to do that on an E28!?!

Your wheels look great by the way & I'm glad you got them in the correct offset

Murfinator · Post by **Murfinator** » Feb 01, 2011 11:48 AM

Black Steel: Thanks for your input. How much power is your motor producing at the wheels? My concern is that when running a motor with 400+ ft/lbs torque that a 265/35-18 tire, despite a large contact patch, will not be capable of maintaining traction no matter the softness or tread wear rating of the tire due to a short and stiff sidewall.

Given that I'll be running 16x9 rear wheels a 265/45-16 Ecsta V710 seems a better fit but I'm still searching. I'm not worried much about wet weather handling because the car won't be driven in the rain.

Black Steel · Post by **Black Steel** » Feb 01, 2011 3:17 PM

Murfinator wrote:Black Steel: Thanks for your input. How much power is your motor producing at the wheels? My concern is that when running a motor with 400+ ft/lbs torque that a 265/35-18 tire, despite a large contact patch, will not be capable of maintaining traction no matter the softness or tread wear rating of the tire due to a short and stiff sidewall.

Given that I'll be running 16x9 rear wheels a 265/45-16 Ecsta V710 seems a better fit but I'm still searching. I'm not worried much about wet weather handling because the car won't be driven in the rain.

You should update your diff to at least 40% lock. 25% is useless with that much torque. E30 M3 track cars use a 75% locking diff!

Also your not going to like that dog leg gearbox.

In the UK they got a bad reputation because first gear was so low that people used second gear to pull away all the time putting extra stress on the bearings which caused them to fail prematurely.

My car is putting out around 340bhp at the crank which with my gearing is more than enough for the cross country driving that I have built it for & with my 6 speed gearbox gives me:

6-speed with 3.45 trans & diff gear overall gear mph:-

@3000rpm = second to last col. @7250rpm = last col.
1st 4.23 14.59 15 mph 37 mph
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

A true Audi killer

Your M30 with an 8:5:1 CR will be putting out 185bhp before the turbo cuts in. If you tailor your boost correctly then by the time all that torque comes in you will be rolling fast enough for traction to be maintained with the 265's.

The question for you to ask yourself is how far do you really want to go? Do you want the car to remain as a road car first, track day toy second or the other way round?

It's a slippery expensive slope!

Murfinator · Post by **Murfinator** » Feb 02, 2011 11:28 AM

Out with the old. Both the cylinder head/intake and the short block are sold.

turbodan · Post by **turbodan** » Feb 02, 2011 9:17 PM

The difference in performance between 265s and 275s will be minimal. The sidewall height won't do anything for you either unless you're running drag radials or slicks. Street tires will just spin.

You shouldn't have to worry about diff locking ratios a whole lot unless you're running on a track. Straight line acceleration and stability are fine with the stock diff in my experience.

Murfinator · Post by **Murfinator** » Feb 02, 2011 10:09 PM

I'm not as concerned with the tire clearance on the inside as I am the hub to fender dimensions. Still need to take some good measurements. The fender lips have been rolled and the gas tank splash guard adjusted to accommodate my 255/40-17 Falken Azenis. It's not worth it to attempt squeezing 275's in there. Since this car will never be a DD and won't see rain I'll be running a track oriented, dry weather tire such as the 265/45-16 Ecsta V710. It's sticky and darn near a slick.

Added sidewall height is driving my wheel choice. I'd love to go with 18's for looks but even at a 265 width they will never outperform a 265/45-16, especially on the track. I won't claim to understand all the physics but here's the basics:

Your coming out of the apex of a turn, you've downshifted and now roll into the throttle with a motor that cranks out 450+ ft/lbs of torque. The shock of this sudden increase in power is transferred through the drive train to the wheel and tire. If the tire is short and stiff the shock is transferred violently through to the tire and traction is lost due to the jerk in twisting force. At this point you're likely skating across the track and into the dirt. Now, if the tire is taller (more sidewall) this shock is better absorbed by the tire rather than transferred violently to the contact area. I'm not going to be drag racing the car from a dead stop but think of a slow-motion video of a drag racer with huge wide slicks and a tall sidewall. The wheels by necessity are bead-locks because in the video you can see the sidewall fold and partially collapse when the power is applied then if the traction is sufficient the tire launches the dragster down the track. Otherwise you get a burnout with little forward motion.

The car will be driven maybe twice a week: up the canyons and out to the track once or twice a month. At the track I was competitive in the turns but in the straights I would lose ground and get passed. Sure, driving skill is one aspect which is being addressed by the excellent driving school at the motorsports park, but the other is the lack of power which necessitated this build. As you'll notice from the track overview there are plenty of turns to slingshot out of and also a nice long straight.

On the freeway while driving to and from the track or canyons I want to stay in 5th (1:1), hit the throttle and pull away from those punks running new M3's. I'll be lighter by 2-300# and will have 10-15% more power on tap. We'll see...

Murfinator · Post by **Murfinator** » Feb 17, 2011 11:19 AM

Progress: bored, o-ringed and decked the block. Balanced the rotating assembly: pistons, rods, crank. Installed restrictors on the oil passages to the cylinder head. Painting the block next: BMW Motorsport Pantone Warm Red

Murfinator · Post by **Murfinator** » Feb 28, 2011 12:41 PM

This just in: MM high-volume, blueprinted oil pump with a bored out pressure relief valve re-sleeved in silicon bronze, smaller sprocket (E32) and shorter chain. Write-up: http://www.metricmechanic.com/catalog/r ... l-pump.php

Black Steel · Post by **Black Steel** » Feb 28, 2011 1:32 PM

Very Very nice

Post by **mooseheadm5** » Feb 28, 2011 1:53 PM

300 worth of oil pump and sprocket? Damn. I'm going to have to start saving more for my build.

SilverBullet · Post by **SilverBullet** » Mar 03, 2011 8:21 AM

Did you install the oil restrictors because of the oil pump you are using or is there another reason?

Murfinator · Post by **Murfinator** » Mar 04, 2011 12:57 AM

SilverBullet wrote:Did you install the oil restrictors because of the oil pump you are using or is there another reason?

I've been told the oil restrictors are prudent due to the higher output of the pump with the smaller sprocket. Also felt the freshened pump was a good investment because it will keep the oil flowing at sufficient pressure from high RPM's to idle. New piston oilers have been installed as a precaution.

Also newly installed...

EuroShark · Post by **EuroShark** » Mar 04, 2011 10:51 AM

Awesome! Keep it coming. I'm excited to see where this is going!

E.rouzbeh.28 · Post by **E.rouzbeh.28** » Mar 06, 2011 8:45 PM

I love how your wheel matches your seats.

Great job on the build so far and I can't wait to see it finished.

ealoken · Post by **ealoken** » Mar 07, 2011 7:13 AM

Nice project

But i have some questions.

Where did u buy the steering wheel?

And, your Turbo exhaust house is WAY to smaal, schould have been 1.06!

Keep the pictures coming:)

George · Post by **George** » Mar 07, 2011 7:45 AM

ealoken wrote:
And, your Turbo exhaust house is WAY to smaal, schould have been 1.06!

Its a T fucking 4 footprint. It will make 500 hp all day long with that housing and A/R.

ealoken · Post by **ealoken** » Mar 07, 2011 8:03 AM

George wrote:
ealoken wrote:
And, your Turbo exhaust house is WAY to smaal, schould have been 1.06!

Its a T fucking 4 footprint. It will make 500 hp all day long with that housing and A/R.

backpressure like a mamuth.
bad respons on top!

500 bhp on a 2 liter engine. This 3.5 liter is pushing WAY more exhaust!

George · Post by **George** » Mar 07, 2011 8:58 AM

ealoken wrote:
George wrote:
ealoken wrote:
And, your Turbo exhaust house is WAY to smaal, schould have been 1.06!

Its a T fucking 4 footprint. It will make 500 hp all day long with that housing and A/R.
backpressure like a mamuth.
bad respons on top!

500 bhp on a 2 liter engine. This 3.5 liter is pushing WAY more exhaust!

You have some learning and testing to do.

ealoken · Post by **ealoken** » Mar 07, 2011 9:03 AM

I say this by experience. I had gt35 and ar82 on my 2.3 liter volvo.
And sevral guys have 500+ on their 3.5 liters, with 1.06 exhaust.

Lurker27 · Post by **Lurker27** » Mar 07, 2011 9:39 AM

ealoken wrote: 500 bhp on a 2 liter engine. This 3.5 liter is pushing WAY more exhaust!

Please explain how 500hp does not = 500hp in terms of air and exhaust flow.

George · Post by **George** » Mar 07, 2011 9:54 AM

I'm not going to clutter up Mike's thread. Pm or email me if you want to further the discussion.

Murfinator · Post by **Murfinator** » Mar 09, 2011 3:18 AM

New upper and lower control arms: Moosehead spherical bearings in the Lemforder UCA's and Grunts in the LCA E34 aluminum sports. If I don't like them I can always press in the originals.

MyE28.com

MyE28.com

GOD'S VENGEANCE - Complete Drivetrain Redux