 Optimum rpm range around town and cruising around 70mph? |
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| Geezer914 |
 Jul 20 2022, 05:31 AM
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#1
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Geezer914  Group: Members Posts: 2,292 Joined: 18-March 09 From: Salem, NJ Member No.: 10,179 Region Association: North East States 
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What is the optimum rpm range for cruising around town or on the highway at 70 mph?
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| Optimusglen |
Jul 20 2022, 10:38 AM
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#2
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Senior Member Group: Members Posts: 940 Joined: 26-February 16 From: Minneapolis Member No.: 19,709 Region Association: Upper MidWest
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Shoot... I'm pushing 4k in my 6 at 70-75ish (IIRC)
Wonder if I should go bigger tires... |
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| VaccaRabite |
Jul 20 2022, 11:47 AM
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#3
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En Garde! Group: Admin Posts: 13,864 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region
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QUOTE(Optimusglen @ Jul 20 2022, 12:38 PM)  Shoot... I'm pushing 4k in my 6 at 70-75ish (IIRC) Wonder if I should go bigger tires... If the gear ratios are the same in a /6 as they are in a /4 - then yes you need taller tires. Your speedo must be way off too. Guessing you are using a 50 series tire? Zach |
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| Optimusglen |
Jul 21 2022, 02:00 PM
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#4
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Senior Member Group: Members Posts: 940 Joined: 26-February 16 From: Minneapolis Member No.: 19,709 Region Association: Upper MidWest
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QUOTE(VaccaRabite @ Jul 20 2022, 12:47 PM) QUOTE(Optimusglen @ Jul 20 2022, 12:38 PM) Shoot... I'm pushing 4k in my 6 at 70-75ish (IIRC) Wonder if I should go bigger tires... If the gear ratios are the same in a /6 as they are in a /4 - then yes you need taller tires. Your speedo must be way off too. Guessing you are using a 50 series tire? Zach I'm running 205/60-15 (627mm diameter) I've only ever used a GPS speedometer, but I may be misremembering the speed/revs. trans is a side shift from a 4-cyl, I don't believe it's been opened. |
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| VaccaRabite |
Jul 22 2022, 10:36 AM
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#5
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En Garde! Group: Admin Posts: 13,864 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region
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QUOTE(Optimusglen @ Jul 21 2022, 04:00 PM) QUOTE(VaccaRabite @ Jul 20 2022, 12:47 PM) QUOTE(Optimusglen @ Jul 20 2022, 12:38 PM) Shoot... I'm pushing 4k in my 6 at 70-75ish (IIRC) Wonder if I should go bigger tires... If the gear ratios are the same in a /6 as they are in a /4 - then yes you need taller tires. Your speedo must be way off too. Guessing you are using a 50 series tire? Zach I'm running 205/60-15 (627mm diameter) I've only ever used a GPS speedometer, but I may be misremembering the speed/revs. trans is a side shift from a 4-cyl, I don't believe it's been opened. QUOTE Nope. The gearing in a stock /6 is shorter. 4 - A, F, N, V, ZD 6 - A, GA, O, V, ZA 5th is shorter so higher RPM at freeway speeds. 2 and 3 are actually taller, 4th is the same. Changing wheels and tires is not gonna be a good fix as the result may make a weird looking car with a speedo that lies. Easy enough to change the gearing. The 914 really does have the best all around modern gearing for all around use. You have to have different gearing as Mike noted above (or be mis-remembering your speed vs revs as you said). Your tires are really close to mine (205/55 r15) and I'm right at 3K when doing 70. With a taller tire you should be revving less, not more. Also, is you car flared? 205/55r15 is the largest tire I could get under mine without rubbing. Did you need to roll your fenders or something to get the 205/60 to fit? Zach |
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| Optimusglen |
Jul 25 2022, 02:34 PM
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#6
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Senior Member Group: Members Posts: 940 Joined: 26-February 16 From: Minneapolis Member No.: 19,709 Region Association: Upper MidWest
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QUOTE(VaccaRabite @ Jul 22 2022, 11:36 AM) You have to have different gearing as Mike noted above (or be mis-remembering your speed vs revs as you said). Your tires are really close to mine (205/55 r15) and I'm right at 3K when doing 70. With a taller tire you should be revving less, not more. Also, is you car flared? 205/55r15 is the largest tire I could get under mine without rubbing. Did you need to roll your fenders or something to get the 205/60 to fit? Zach Guessing the error is in my memory, I'll check next time I have it at highway speeds. Not flared, but I did roll the inner lips flat in the rear. (IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-19709-1658781262.1.jpg) |
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Posts in this topic
Geezer914 Optimum rpm range around town and cruising around 70mph? Jul 20 2022, 05:31 AM
930cabman
What is the optimum rpm range for cruising around... Jul 20 2022, 05:51 AM BeatNavy For what purpose? Engine longevity/cooling, momen... Jul 20 2022, 05:57 AM GregAmy Chris Foley told me the same: use revs 3k or above... Jul 20 2022, 06:25 AM emerygt350 My stock 2.0 definitely likes 3k. At 60 in fifth ... Jul 20 2022, 06:32 AM
DRPHIL914
My stock 2.0 definitely likes 3k. At 60 in fifth... Jul 20 2022, 07:37 AM VaccaRabite Yup. The rule of thumb is that 70mph at 3K rpm is... Jul 20 2022, 08:42 AM mgphoto Biggest factor on these little cars for cruising R... Jul 20 2022, 09:26 AM DRPHIL914
Shoot... I'm pushing 4k in my 6 at 70-75ish ... Jul 20 2022, 12:43 PM Dr Evil
Shoot... I'm pushing 4k in my 6 at 70-75ish ... Jul 21 2022, 10:08 AM Cairo94507 I think I am at about 2,600 RPM at 70 MPH; I am ru... Jul 20 2022, 12:19 PM windforfun I prefer 3K rpm or slightly more for general respo... Jul 20 2022, 02:48 PM emerygt350 I run 225/50r16s. My speedo is about 4 mph fast at... Jul 20 2022, 03:05 PM Olympic 914
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I run 225/50r16s. My speedo is about 4 mph fast ... Jul 21 2022, 07:18 AM wonkipop near enough around 3K at 70mph in 5.
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