Cruising RPM at 80mph DCT in 7th

adameldridge · 10-09-2021, 09:29 AM

Hey fellas.

New to me M3 in 7th at 80mph im north of 3500RPM. Seems awful high to me. 2013 Comp DCT in Manual Shift Mode. Wondering if I've got different gear ratio in the Diff. ??

Thank for your input

DukeofAlexandria · 10-09-2021, 09:59 AM

Quote:

Originally Posted by adameldridge

Hey fellas.

New to me M3 in 7th at 80mph im north of 3500RPM. Seems awful high to me. 2013 Comp DCT in Manual Shift Mode. Wondering if I've got different gear ratio in the Diff. ??

Thank for your input

Uhhhh, that COULD be right. What tire sizes are you running?

Quick math with a 3.154 ratio, 1.00 7th gear and 3500 gets you to around 80+, but I have to use a ridiculously small tire. What is that and we can tell you more, thx.

Edit; additionally, give EXACT numbers: wtf does "north of 3500" mean? Yes, it matters.

-Duke

CamasM3e93 · 10-09-2021, 04:14 PM

Quote:

Originally Posted by adameldridge

Hey fellas.

New to me M3 in 7th at 80mph im north of 3500RPM. Seems awful high to me. 2013 Comp DCT in Manual Shift Mode. Wondering if I've got different gear ratio in the Diff. ??

Thank for your input

That sounds high. I have 19s and I think 80 is more like 3200. I'll check it out and get back to you

slcook54 · 10-09-2021, 04:21 PM

Roughly 3200 at 80mph with 275/35/18

Davisca455 · 10-09-2021, 05:18 PM

3500rpm is closer to 87mph (90mph indicated) for my '08.
Front 245/35/19
Rear 305/30/19
Diff = OEM

Redd · 10-09-2021, 07:52 PM

Based on 255/35/19 tires, the 7th gear speed at 3500rpm for each final drive are:

3.15 (stock) = 86 mph
3.45 = 78 mph
3.62 = 75 mph

You may have an aftermarket final drive.

omgzirra_exe · 10-10-2021, 01:22 AM

Quote:

Originally Posted by adameldridge

Hey fellas.

New to me M3 in 7th at 80mph im north of 3500RPM. Seems awful high to me. 2013 Comp DCT in Manual Shift Mode. Wondering if I've got different gear ratio in the Diff. ??

Thank for your input

buys a dinan M3, yet super confused on why it has a high rpm.. ITS BECAUSE YOU HAVE A DINAN M3

DukeofAlexandria · 10-10-2021, 08:24 AM

Quote:

Originally Posted by omgzirra_exe

Quote:

Originally Posted by adameldridge

Hey fellas.

New to me M3 in 7th at 80mph im north of 3500RPM. Seems awful high to me. 2013 Comp DCT in Manual Shift Mode. Wondering if I've got different gear ratio in the Diff. ??

Thank for your input

buys a dinan M3, yet super confused on why it has a high rpm.. ITS BECAUSE YOU HAVE A DINAN M3

Uhhhh, where did he say it was a dinan M3? He said it was a comp package (zcp), not a dinan.

And even if he had said dinan, since when did the stage 1 or 2 do anything with gear ratios or DCT final drive ratios? I was under the impression both (zcp and dinan) messed with suspension, edc, and a few other cosmetics.

Edit: just read his other post on the 4.6; that doesn't make a difference either, as dinan never adjusted or changed dct/gear ratios here either. At least that's what the package originally said….

-Duke

mubarak · 10-10-2021, 02:04 PM

Quote:

Originally Posted by Davisca455

3500rpm is closer to 87mph (90mph indicated) for my '08.
Front 245/35/19
Rear 305/30/19
Diff = OEM

Stock wheel for 305 in rears?
Oil temp too high !!!!! Even in 40C here I do not get this high.

Davisca455 · 10-10-2021, 04:26 PM

Quote:

Originally Posted by mubarak

Quote:

Originally Posted by Davisca455

3500rpm is closer to 87mph (90mph indicated) for my '08.
Front 245/35/19
Rear 305/30/19
Diff = OEM

Stock wheel for 305 in rears?
Oil temp too high !!!!! Even in 40C here I do not get this high.

Widened (to the inboard side) stock rear wheels allow the 305s.
I eventually added 5mm spacers though, because at full suspension droop (like getting airborne over a RR crossing) the inside of the rear tires would just touch the V-Brace.

The 265s just didn't have enough grip once the blower was installed.

Much better traction now, plus stealth.

Normally the oil temp needle is on or near the 210 mark.
But when I took the picture it was 106f outside, I'd been on the road for 6 hours, was in the mountains between California and Oregon, and had just finished doing some pulls with a Lamborghini.

Also, my oil temps will easily get above the 255f mark when I'm on track.

CamasM3e93 · 10-10-2021, 07:28 PM

Quote:

Originally Posted by adameldridge

Hey fellas.

New to me M3 in 7th at 80mph im north of 3500RPM. Seems awful high to me. 2013 Comp DCT in Manual Shift Mode. Wondering if I've got different gear ratio in the Diff. ??

Thank for your input

Dct on 19" wheels, barely 3100 rpm

DRLane · 10-10-2021, 09:34 PM

Quote:

Originally Posted by CamasM3e93

Quote:

Originally Posted by adameldridge

Hey fellas.

New to me M3 in 7th at 80mph im north of 3500RPM. Seems awful high to me. 2013 Comp DCT in Manual Shift Mode. Wondering if I've got different gear ratio in the Diff. ??

Thank for your input

Dct on 19" wheels, barely 3100 rpm

It's tire diameter not wheel size that's impacting

CamasM3e93 · 10-10-2021, 10:12 PM

Quote:

Originally Posted by DRLane

Quote:

Originally Posted by CamasM3e93

Quote:

Originally Posted by adameldridge

Hey fellas.

New to me M3 in 7th at 80mph im north of 3500RPM. Seems awful high to me. 2013 Comp DCT in Manual Shift Mode. Wondering if I've got different gear ratio in the Diff. ??

Thank for your input

Dct on 19" wheels, barely 3100 rpm

It's tire diameter not wheel size that's impacting

Uh huh. You feeling ok?

Gossypiboma · 10-10-2021, 10:19 PM

Quote:

Originally Posted by CamasM3e93

Uh huh. You feeling ok?

Well he's correct.

DrFerry · 10-11-2021, 08:47 AM

Quote:

Originally Posted by Gossypiboma

Quote:

Originally Posted by CamasM3e93

Uh huh. You feeling ok?

Well he's correct.

This calculator might help..

https://www.blocklayer.com/rpm-gear.aspx
.

Helmsman · 10-11-2021, 09:35 AM

Quote:

Originally Posted by Davisca455

Widened (to the inboard side) stock rear wheels allow the 305s.
I eventually added 5mm spacers though, because at full suspension droop (like getting airborne over a RR crossing) the inside of the rear tires would just touch the V-Brace.

The 265s just didn't have enough grip once the blower was installed.

Much better traction now, plus stealth.

Normally the oil temp needle is on or near the 210 mark.
But when I took the picture it was 106f outside, I'd been on the road for 6 hours, was in the mountains between California and Oregon, and had just finished doing some pulls with a Lamborghini.

Also, my oil temps will easily get above the 255f mark when I'm on track.

How did it go vs the Lambo..?

Davisca455 · 10-11-2021, 10:07 AM

Quote:

Originally Posted by Helmsman

Quote:

Originally Posted by Davisca455

Widened (to the inboard side) stock rear wheels allow the 305s.
I eventually added 5mm spacers though, because at full suspension droop (like getting airborne over a RR crossing) the inside of the rear tires would just touch the V-Brace.

The 265s just didn't have enough grip once the blower was installed.

Much better traction now, plus stealth.

Normally the oil temp needle is on or near the 210 mark.
But when I took the picture it was 106f outside, I'd been on the road for 6 hours, was in the mountains between California and Oregon, and had just finished doing some pulls with a Lamborghini.

Also, my oil temps will easily get above the 255f mark when I'm on track.

How did it go vs the Lambo..?

I came up from behind him catching the pack he was maneuvering thru, he picked up his pace when I got to his bumper, so rather than pass, I tucked in behind him and we were together maneuvering thru traffic for 45 minutes to an hour, between 80-90 mph depending if a pass was being made.
At some point he moved to the right lane to let me pass, then he followed me.

We were in the left lane, just clearing a pack of cars as a looong straight section of open freeway appeared, no cars in sight ahead for miles.
From my mirror I could tell he also saw the wide open freeway approaching, and he closed up the gap on my rear bumper. As we cleared the last car in the pack we were going thru, he moved to the right lane, I was still leading, I dropped a couple gears and nailed it.
He nailed it as well.
He did not catch me, but I did not increase the distance between us.
Acceleration wise, the cars were very close.

(His car sounded WICKED!!!)

Helmsman · 10-11-2021, 10:14 AM

Quote:

Originally Posted by Davisca455

I came up from behind him catching the pack he was maneuvering thru, he picked up his pace when I got to his bumper, so rather than pass, I tucked in behind him and we were together maneuvering thru traffic for 45 minutes to an hour, between 80-90 mph depending if a pass was being made.
At some point he moved to the right lane to let me pass, then he followed me.

We were in the left lane, just clearing a pack of cars as a looong straight section of open freeway appeared, no cars in sight ahead for miles.
From my mirror I could tell he also saw the wide open freeway approaching, as he closed up the gap on my rear bumper. As we cleared the last car in the pack we were going thru, he moved to the right lane, I was still leading, I dropped a couple gears and nailed it.
He nailed it as well.
He did not catch me, but I did not increase the distance between us.
Acceleration wise, the cars were very close.

(His car sounded WICKED!!!)

What a great little story, and love the ending - thanks mate!

Davisca455 · 10-11-2021, 10:23 AM

Quote:

Originally Posted by Helmsman

Quote:

Originally Posted by Davisca455

I came up from behind him catching the pack he was maneuvering thru, he picked up his pace when I got to his bumper, so rather than pass, I tucked in behind him and we were together maneuvering thru traffic for 45 minutes to an hour, between 80-90 mph depending if a pass was being made.
At some point he moved to the right lane to let me pass, then he followed me.

We were in the left lane, just clearing a pack of cars as a looong straight section of open freeway appeared, no cars in sight ahead for miles.
From my mirror I could tell he also saw the wide open freeway approaching, as he closed up the gap on my rear bumper. As we cleared the last car in the pack we were going thru, he moved to the right lane, I was still leading, I dropped a couple gears and nailed it.
He nailed it as well.
He did not catch me, but I did not increase the distance between us.
Acceleration wise, the cars were very close.

(His car sounded WICKED!!!)

What a great little story, and love the ending - thanks mate!

I do sometimes wonder what he was thinking though…

"How cute, the old man in the M3 thinks he has a cool car…I'm gonna blast by him and give him a real thrill….oh dear lord the old guy is dropping gears, you have got to be kidding me…fine, I'll put him out of his misery….WTF!!!? Why-am-I-not-catching-a-fucking-M3?"

DRLane · 10-11-2021, 02:46 PM

Quote:

Originally Posted by CamasM3e93

Quote:

Originally Posted by DRLane

Quote:

Originally Posted by CamasM3e93

Quote:

Originally Posted by adameldridge

Hey fellas.

New to me M3 in 7th at 80mph im north of 3500RPM. Seems awful high to me. 2013 Comp DCT in Manual Shift Mode. Wondering if I've got different gear ratio in the Diff. ??

Thank for your input

Dct on 19" wheels, barely 3100 rpm

It's tire diameter not wheel size that's impacting

Uh huh. You feeling ok?

Yes, but you included wheel size with definitive RPM like it meant something. That's all.

Helmsman · 10-13-2021, 02:56 AM

Quote:

Originally Posted by Davisca455

I do sometimes wonder what he was thinking though…

"How cute, the old man in the M3 thinks he has a cool car…I'm gonna blast by him and give him a real thrill….oh dear lord the old guy is dropping gears, you have got to be kidding me…fine, I'll put him out of his misery….WTF!!!? Why-am-I-not-catching-a-fucking-M3?"

Hahaha!

...

I bet thats exactly what was going on inside the Lambo!

10-09-2021, 09:29 AM	#1
adameldridge New Member 7 Rep 9 Posts Drives: E92 M3 4.6 Dinan, E39T, E38 Join Date: Oct 2021 Location: TX iTrader: (0)	Cruising RPM at 80mph DCT in 7th Hey fellas. New to me M3 in 7th at 80mph im north of 3500RPM. Seems awful high to me. 2013 Comp DCT in Manual Shift Mode. Wondering if I've got different gear ratio in the Diff. ?? Thank for your input
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10-09-2021, 04:21 PM	#4
slcook54 Captain 1875 Rep 893 Posts Drives: 2012 MR M3 / 2018 SMB M3 CS Join Date: Aug 2014 Location: San Francisco iTrader: (0)	Roughly 3200 at 80mph with 275/35/18 __________________ Instagram: slcook54
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10-09-2021, 05:18 PM	#5
Davisca455 Captain 2242 Rep 867 Posts Drives: 2008 M3 Join Date: Oct 2012 Location: Davis, California iTrader: (0)	3500rpm is closer to 87mph (90mph indicated) for my '08. Front 245/35/19 Rear 305/30/19 Diff = OEM Attached Images __________________ Chris, 2008 E92
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10-09-2021, 07:52 PM	#6
Redd Brigadier General 5039 Rep 4,842 Posts Drives: 2010 BMW E92 M3 Dakar Edition Join Date: Jul 2015 Location: Malaysia iTrader: (0)	Based on 255/35/19 tires, the 7th gear speed at 3500rpm for each final drive are: 3.15 (stock) = 86 mph 3.45 = 78 mph 3.62 = 75 mph You may have an aftermarket final drive.
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