GOD'S VENGEANCE - Complete Drivetrain Redux

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.

derrith · Post by **derrith** » Mar 12, 2011 11:31 AM

Murfinator wrote: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.

Any reason you went with urethane for the lcabs over installing e31 monoball lowers?

Murfinator · Post by **Murfinator** » Mar 12, 2011 9:09 PM

derrith wrote: Any reason you went with urethane for the lcabs over installing e31 monoball lowers?

Like these? : http://cgi.ebay.com/ebaymotors/ws/eBayI ... K:MEWAX:IT

I've had the Grunts sitting in a box for a few years after having purchased them on eBay for $35 shipped. Had them posted here in a FS thread for a month with no interest. If they fall apart I'll go with spherical bearings in the LCA's.

Murfinator · Post by **Murfinator** » Mar 20, 2011 3:59 PM

paul burke wrote:
Murfinator wrote:
T_C_D wrote:Major update. I have some explaining to do. As it turns out my freshly built JE piston engine only lasted 500 miles. The machine shop didn't bore the cylinders large enough so the pistons almost seized. The rings were frozen. The pistons were galled. The cyl walls were trashed.
That's terrible! It would be my worse nightmare to get a major build completed only to have the motor fail in <500 miles.
Mike, from the pictures it looks like they did a good job on yours, restrictors appear to be correct size (.109 and change). If you want to purchase a cheap dial bore gauge and a 3 to 4 micrometer I will walk you through the measuring process.

Paul

...continued from Todd's thread regarding issues with his freshly built motor at less than 500 miles likely caused by improperly bored cylinders:

Would the cheap measuring tools at Harbor Freight work? Looked around at the local auto parts store and didn't find anything that seemed like it would be any more accurate than my Blue Point digital calipers. I measured the bore diameter and came up with 92.35 mm. The spec sheet with the pistons calls for 92.5 mm. I'll be taking the motor back to the machine shop for balancing of the rotating assembly. Should I have the bores opened some more? Note I only measured the bores at the tops and not throughout the bore. eBay perhaps?

Post by **mooseheadm5** » Mar 20, 2011 4:03 PM

Calipers are not the right tool for the job. You should grab the bore gauge as suggested.

Murfinator · Post by **Murfinator** » Apr 10, 2011 4:40 PM

Motor painted BMW Motorsport Warm Red:

Black Steel · Post by **Black Steel** » Apr 11, 2011 6:52 AM

Cool colour.

My block is painted red.

Corner Carver · Post by **Corner Carver** » Apr 11, 2011 10:52 PM

I like it!

Actually, I am surprised how much I do like it

The red really brings out the nuances of the block, much more than black does

Thanks Mike...... now there is a red block in my future

Cooperman · Post by **Cooperman** » Jun 01, 2011 1:16 PM

Bump for update

fries_man · Post by **fries_man** » Jun 01, 2011 2:30 PM

Murfinator, I like that red block!

Which paint did you use on it?

Murfinator · Post by **Murfinator** » Jun 01, 2011 3:25 PM

fries_man wrote:Murfinator, I like that red block!
Which paint did you use on it?

I did some research into the Pantone/RAL colors which correspond most closely with the BMW Motorsport colors. Warm Red is the Pantone color which is the closest match. My local finishing shop has my notes with the actual numbers. I purchased two pint cans of Rennsport ROT (stock # 107409) by Uno. Since they mixed it for me I cannot return the second pint can that I have no need for. The local machine shop who frequently paint engine blocks recommended this brand for its excellent heat and oil resistance. I mixed it with the recommended proportions of reducer and hardener and sprayed it through an air gun. Two medium coats provided excellent coverage with only a couple sags due to the uneven surface. Overall I'm pleased with the result.

If you're interested in the extra pint of paint let me know.

MyE28.com

MyE28.com

GOD'S VENGEANCE - Complete Drivetrain Redux