Author Topic: How can I improve throttle response? (Read 7931 times)

P. Kennedy · « **on:** August 17, 2007, 05:28:08 PM »

It takes a fair amount of gas pedal to get my beat 318is moving. What steps can I take to improve the throttle response? If you were to say "buy a Mark D. chip," that would be great, as I am looking for an excuse to get one. But other suggestions welcome.

denious · « **Reply #1 on:** August 17, 2007, 05:29:47 PM »

Lighter flywheel? The m42 one's ridiculously heavy..

ak96ss · « **Reply #2 on:** August 17, 2007, 05:34:04 PM »

+1 on the lighter flywheel - I wish I had one. It takes a fair amount of time to get all elebenty-billion pounds rotating... well, really only like 30 lbs, but still....

Make sure your AFM is in tip-top shape. I understand a conversion to a MAF will help, but don't know that it helps enough to make it worthwhile. Someone with some experience in that should chime in here.

Lukis · « **Reply #3 on:** August 17, 2007, 05:38:30 PM »

If you swap to a alloy flywheel, or a early m20 flywheel you would get better resons.
In case you got a bigger budget you could change the intake manifold.

BrandC · « **Reply #4 on:** August 17, 2007, 08:11:00 PM »

Tighten your throttle cable.

P. Kennedy · « **Reply #5 on:** August 17, 2007, 08:19:45 PM »

Thanks hombres. I hope to do a flywheel swap in the not too distant future.

christophbmw · « **Reply #6 on:** August 18, 2007, 12:38:53 PM »

....get the revs up above 4K, that should do the trick.

Kedge · « **Reply #7 on:** September 03, 2007, 08:26:05 AM »

Removing the heater plate on the throttle body is meant to make a difference as well. Yet to get the engine in yet to see the difference yet though.

bmwman91 · « **Reply #8 on:** September 03, 2007, 10:00:18 AM »

Try tightening the throttle cable a little. If the pedal does not press perfectly smooothly and there is a lot of resistance, you need to replace the cable. THa can make a world of difference.

+2 on the flywheel. Best mod aside from a chip.

If you press the pedal and the motor does anything short of revving happily & willingly, you might have problems. Maybe a vacuum leak or bad AFM? How does the motor do above 4000RPM?

P. Kennedy · « **Reply #9 on:** September 03, 2007, 02:09:01 PM »

Thanks for your response. My throttle cable appears to be somewhat screwed up, there's electrical tape holding things together. I will attempt to get that sorted out. Above 4K, the car runs like a scalded dawg!

asubimmer · « **Reply #10 on:** September 03, 2007, 04:17:55 PM »

convert to a electric fan also.

bmwman91 · « **Reply #11 on:** September 03, 2007, 05:18:08 PM »

You know, I have heard many many things regarding the electric fan swap. Assuming you did it (and nothing else simultaneously), did it really make a difference in response? I am always looking for an excuse to mess with things in there, but the cost/benefit ratio I hear about this put me off a bit.

tjts1 · « **Reply #12 on:** September 03, 2007, 09:00:37 PM »

If you have a good functioning clutch fan that shows a lot of resistance when you try to turn it while hot, yes you will notice the difference with the clutch fan. I tried it out at first by simply driving the car with the clutch fan removed (cold night, no idling) and I was convinced. Also removed the PS which also helps in throttle response. Next step for me is chip and flywheel.

asubimmer · « **Reply #13 on:** September 03, 2007, 11:19:48 PM »

Quote from: tjts1;33016

If you have a good functioning clutch fan that shows a lot of resistance when you try to turn it while hot, yes you will notice the difference with the clutch fan. I tried it out at first by simply driving the car with the clutch fan removed (cold night, no idling) and I was convinced. Also removed the PS which also helps in throttle response. Next step for me is chip and flywheel.

qft

I removed my fan clutch and it was deff noticable. I decided to go electric. But I have since taken off the PS, AC and have the m20 single mass flywheel now. Throttle response is pretty good I would say, although its not ITBS...

ose30 · « **Reply #14 on:** September 04, 2007, 08:19:23 AM »

Quote

early m20 flywheel you would get better resons

I suppose M40 engine is not available in the USA? In Europe 316I & 318I use 1,6 & 1,8 liter variants of M40 engine. basically it is a 8V version of M42 engine. M40 flywheel is lighter than M20 flywheel and it is a direct bolt on job to M42 engines. Actually most of the european 318IS have this flywheel, because in most cases 318IS does not have AC. Plenty of those flywheels available in Europe.