what performance mods can you do with a e46er m3 without running a chance of blowing her? :dunno

AC Schnitzer 3.91 ///M rear differential upgrade.

Suspension
Brakes
Wheels/Tires
Fuzzy Dice (did I just say that?)
Exhaust

Originally posted by themadhatter
AC Schnitzer 3.91 ///M rear differential upgrade.
stupid question...but what does this upgrade do and how much does it cost?:95

Originally posted by E462k3m3

stupid question...but what does this upgrade do and how much does it cost?:95

changes gear ratios! :)

I think higher gear ratios = faster acceleration, less top speed and lower gear ratios = slower acceleration higher top speed!

someone correct me if i'm wrong!:dunno

Originally posted by BoostFed325
what performance mods can you do with a e46er m3 without running a chance of blowing her? :dunno

wash it with Zaino, you'll get better drag! :D

You can get the new engine mod which Phantom,Jon and myself have recently put in, its nice :)

Enigma is gonna organize a group buy I heard.

Brian

Originally posted by marwan


changes gear ratios! :)

I think higher gear ratios = faster acceleration, less top speed and lower gear ratios = slower acceleration higher top speed!

someone correct me if i'm wrong!:dunno

Marwan is basically correct. With the E46 M3, gearing is estimated at over 200mph with the current setup. You'll never see that speed in an M3 without serious aerodynamic and motor work.

So, ACS devised a non-invasive upgrade. The rear diff is an excess of $3,000 and dramatically increases acceleration without hurting the limited/unlimited top speed of the car. Better quarter mile times, better acceleration and possibly a higher usable top speed.

Of course you could supercharge the car for a little more and risk blowing up your engine. :biglaughb

Changing the final drive ration will NOT do much for your acceleration. It helps acceleration in 1st gear but that is it. It forces you to make your shifts at lower speeds. You will need 3 gears to get to 60. Odds are this will make you slower espically because the car is mostly traction limited on street tires anyway.

For those simply into drag racing it will help you get a better 60' time.

TC-Kline has a lightweight flywheel & clutch for the car. A few places have exausts and chip upgrades. I would not expect much more than 15hp max improvement without MAJOR work.

Hamman has the airbox and chip, but not sure how much it's good for. Just wait for the CSL to be produced, then you can pickup the BMW intake.
Nowack has a 400HP upgrade that involves opening the engine and changin out the rods, pistons and I think the cams as well. You'll also need 100 Octane fuel and it revs to 8400 RPM... don't know how good an idea that is but at least the internals are strengthened, unlike the Hamman software that also increases the redline to 8400.

Originally posted by Enigma
Changing the final drive ration will NOT do much for your acceleration. It helps acceleration in 1st gear but that is it. It forces you to make your shifts at lower speeds. You will need 3 gears to get to 60. Odds are this will make you slower espically because the car is mostly traction limited on street tires anyway.

For those simply into drag racing it will help you get a better 60' time.

TC-Kline has a lightweight flywheel & clutch for the car. A few places have exausts and chip upgrades. I would not expect much more than 15hp max improvement without MAJOR work.

what's wrong with having to shift up at 30mph? I don't own it, but I'm sure ACS did their homework on this piece before releasing it. Besides, it's completely hidden...not that the car is a sleeper of course. :) But I'd have to respectfully disagree that it only helps in first gear.

Originally posted by themadhatter
what's wrong with having to shift up at 30mph? I don't own it, but I'm sure ACS did their homework on this piece before releasing it. Besides, it's completely hidden...not that the car is a sleeper of course. :) But I'd have to respectfully disagree that it only helps in first gear.

It does only improve acceleration in 1st gear. The car with the stock final drive will still be in 1st while the modified car has shifted into 2nd. This will give the advantage to the stock car. Once the stock car shifts to 2nd then the modified car has the edge again and it goes back and forth. On a run from more than 30mph I doubt there would be noticable diffrence in acceleration.

Its all just math. Yes each gear pulls harder in a car with a shorter final drive, but since you spend much of you time in a higher gear you don't gain anything. This subject has been beaten to death in a number of texts.

The reason you DO gain in 1st is because there is no lower gear for the stock car to be in at the launch.

Bottom line is that this is is a drag racing modification.

I have heard that the ACS exaust can COST hp so I wouldn't put a lot of faith in them doing their homework.

I know you are looking at engine/exhaust mods; however, a good lightweight set of wheels will help reduce unsprung weight and benefit acceleration and handling.

I think the wheel that most of us are using on the track is SSR Competition. Stock 18"s and 19" are roughly 24lbs each (19"s are forged) and the 18"s SSR Comp are roughly 16lbs front and 18 lbs rear.

http://www.wheelweights.net/ has a good page which shows the weights for various wheels. When you see how little the SSR Comps weigh in comparison to the others you will be calling Tire Rack or EvoSport the next day!

Just my $0.02

Originally posted by Enigma

Bottom line is that this is is a drag racing modification.

I have heard that the ACS exaust can COST hp so I wouldn't put a lot of faith in them doing their homework.


I understand your point on the diff.

As for the exhaust, where have you heard this from? Their systems are designed and manufactured with aid from one of the largest OE and aftermarket manufacturers in the world. They didn't take a universal system and slap on specific pipes. It was designed for that specific car.

-Ron

Originally posted by themadhatter
As for the exhaust, where have you heard this from? Their systems are designed and manufactured with aid from one of the largest OE and aftermarket manufacturers in the world. They didn't take a universal system and slap on specific pipes. It was designed for that specific car.

-Ron

I heard the same thing... I heard a car lost 7HP when the put the ACS exhaust on. I never saw a dyno chart, but that's what I heard...

Since we're on the subject, when is the appropriate time to shift into second gear (and third) on a fully broken in vehicle? I heard every 15 mph for normal driving but what about drag racing or for quick acceleration...is it to redline???

That will depend on the car. Ideally you want to shift where the RWTQ for the next gear is the same as the current gear.

Since you don't normally have this information available the next best thing is to look at a dyno chart of the car and figure out where the hp for the shift RPM is roughly equal to the hp for the RPM in the next gear. This will always result in a shift point above the HP peak of the engine.

In our cars shifting at readline is a pretty safe bet unless you have some odd modifications that move the peak power down in the power band.

Originally posted by Enigma
That will depend on the car. Ideally you want to shift where the RWTQ for the next gear is the same as the current gear.

Since you don't normally have this information available the next best thing is to look at a dyno chart of the car and figure out where the hp for the shift RPM is roughly equal to the hp for the RPM in the next gear. This will always result in a shift point above the HP peak of the engine.

In our cars shifting at readline is a pretty safe bet unless you have some odd modifications that move the peak power down in the power band.

So, where can I get a dyno chart for a 2002 M3? (and what does RWTQ stand for anyway?)

On the M3 since the HP peak is 7900 and the readline is 8000 just shift at the redline and you will be good.

RWTQ = Rear Wheel Torque

Originally posted by badbadm
You should shift when the SMG shiftlights tell you to.

Unfortunately, manual transmission involves a little more human judgement...no lights that tell you when to shift.

with 4-wheel drive and front wheel drive becoming ever popular I am beginning to think in my mind:
Real World HP and TQ rather than Rear Wheel
:dunno

Brakes, suspension (I have completely replaced my suspension, thinking about brakes) you still have warranty. Personnaly I will do nothing to to my driveline. With the uncertainty of whether or not you were unlucky enough to end up with a hand grenede engine, I wouldn't touch anything in the driveline while in warranty.