1st gear acceleration

1st gear acceleration

Author
Discussion

dan101smith

Original Poster:

16,857 posts

217 months

Monday 23rd June 2008
quotequote all
...on my M3 Evo feels nowhere near as quick as I'd expect, but not a problem in any other gear. Definitely feels like it's being held back - is there some sort of electronic restriction around this, or am I just being daft?

Neil.D

2,878 posts

212 months

Monday 23rd June 2008
quotequote all
No there is, you're not going mad. I have never really found out the cause, but yes, it is ever so slightly restricted.

Neil

dan101smith

Original Poster:

16,857 posts

217 months

Monday 23rd June 2008
quotequote all
OK...so the next question is how does it know I'm in 1st gear to apply the restriction? I didn't think a manual gearbox had a "gear indicator" sensor?

tdm34ds

7,394 posts

216 months

Monday 23rd June 2008
quotequote all
It's a common thing on big bikes to have the torque limited in the first three gears
to stop you looping them, I believe that a lot of hi-power cars have torque limiting in the
first two gears to protect the gearbox,diff and the tyres and/or to prevent traction problems.

Regards Gandalf..............................

derestrictor

18,764 posts

267 months

Monday 23rd June 2008
quotequote all
tdm34ds said:
It's a common thing on big bikes to have the torque limited in the first three gears
to stop you looping them, I believe that a lot of hi-power cars have torque limiting in the
first two gears to protect the gearbox,diff and the tyres and/or to prevent traction problems.

Regards Gandalf..............................
Indeed; t'M5 suffered this. Briefly.

M3John

5,974 posts

225 months

Monday 23rd June 2008
quotequote all
I'm glad you've mentioned this as i've recently converted mine from SMG to manual and although it feels a bit more resposive in-gear whilst on the move, 1st on the other hand feels as if it's being held back ever so slightly, not as violent as the SMG on `take off`.

Edited by M3John on Monday 23 June 18:58

lingus75

1,698 posts

228 months

Tuesday 24th June 2008
quotequote all
I cant find the thread but there is a detailed fix for this issue on the Evo. It's a small wire connected to a point on the gearbox which limits the torque in 1st gear. You can launch it with about 3.5k revs and get traction but it does feel slightly artificial. By removing this you can get full power but risk frying the clutch etc..........

If you do a search then you will find the article.

gwatson

2,565 posts

247 months

Tuesday 24th June 2008
quotequote all
lingus75 said:
I cant find the thread but there is a detailed fix for this issue on the Evo. It's a small wire connected to a point on the gearbox which limits the torque in 1st gear. You can launch it with about 3.5k revs and get traction but it does feel slightly artificial. By removing this you can get full power but risk frying the clutch etc..........

If you do a search then you will find the article.
Very interesting. I've also tried a search but not found anything, would love to try it though.

G

M3John

5,974 posts

225 months

Tuesday 24th June 2008
quotequote all
lingus75 said:
I cant find the thread but there is a detailed fix for this issue on the Evo. It's a small wire connected to a point on the gearbox which limits the torque in 1st gear. You can launch it with about 3.5k revs and get traction but it does feel slightly artificial. By removing this you can get full power but risk frying the clutch etc..........

If you do a search then you will find the article.
Be sure to post back up on here if you do find it please !

gwatson

2,565 posts

247 months

Wednesday 25th June 2008
quotequote all
cluelesscarnut said:
I've been doing a bit of reading on this last night, but it's not conclusive if A) It actually makes a difference and B) if you need to remove the connector or bridge it.

G

AM-BM

261 posts

206 months

Thursday 26th June 2008
quotequote all
Hmmm, this is interesting. I have never heard of any restrictions like this before. But now you mention it, the car does seem to lack a little midrange in 1st as opposed to the rest of the gears!?

AM-BM

261 posts

206 months

Thursday 2nd October 2008
quotequote all
I think we need to investigate this. I would like to remove this restrictor. It really hapers my acceleration in 1st. It definatly struggles in first untill about 5000 rpm, a flat spot. The rest of the gears are fine!?
I had trouble with a blinkin Merc E320 Diesel up to 40mph for godness sake!

E30M3SE

8,475 posts

202 months

Thursday 2nd October 2008
quotequote all
AM-BM said:
I had trouble with a blinkin Merc E320 Diesel up to 40mph for godness sake!
That maybe something to do with the 400 lb/ft of torque he has from 1500rpm upwards and his 7 speed gearboox if it was latest model.

AM-BM

261 posts

206 months

Thursday 2nd October 2008
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Er 400 !!!! Yep was 08 model!
quick but still nailed him in the other gears!

E30M3SE

8,475 posts

202 months

Thursday 2nd October 2008
quotequote all
AM-BM said:
Er 400 !!!! Yep was 08 model!
quick but still nailed him in the other gears!
Sounds about right then.

tjw110

498 posts

228 months

Thursday 2nd October 2008
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I find this can be overcome when you light up the rears, yes it's going to cost you in tyres, but theres no hesitation in 1st when you do it

AM-BM

261 posts

206 months

Thursday 2nd October 2008
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Lol, I would love to and will be tracking it soon before I get some new tyres :-)

Seriously though, I gonna have to get to the bottom of this first gear power loss, since dan101 mentioned it I have really noticed it!

daveco

4,218 posts

213 months

Thursday 2nd October 2008
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Does anyone know if this is the case with the E46 330ci?

breezy

180 posts

232 months

Thursday 2nd October 2008
quotequote all
dan101smith said:
...on my M3 Evo feels nowhere near as quick as I'd expect, but not a problem in any other gear. Definitely feels like it's being held back - is there some sort of electronic restriction around this, or am I just being daft?
Think that the ignition timing in first gear is retarded to avoid breaking traction. Couldn't tell you how the car knows what gear you are in however...