SuzukiSavage.com - 5000 rpm safe?

Dave

YaBB Moderator
ModSquad

Offline

SuzukiSavage.com
Rocks!

Posts: 18101
Camp Springs, Kentucky
Gender: male

Re: 5000 rpm safe?
Reply #75 - 01/07/17 at 11:08:07

A low rpm engine will still make HP, and it will still have torque.......however the torque value in ft/lbs will be a larger number than the HP value.

Think of the old steam traction engines.....they turned low rpm but made a lot of torque. A 110 HP traction engine has 3,000 ft/lb of torque at 240 rpm......and they could pull 20 plows at once!

https://www.youtube.com/watch?v=EVxByLO_6cA

Back to top

Someday I will be old......But not today!

IP Logged

piedmontbuckeye

Senior Member

Offline

Go Bucks!

Posts: 496
Easley, SC
Gender: male

Re: 5000 rpm safe?
Reply #76 - 01/07/17 at 12:02:38

Kris01 wrote on 01/06/17 at 16:01:14:

If you ever over-rev the engine, you'll know it! It sounds like it's going to explode way before you get to max RPMs! Cheesy

I guess knowing the peak torque/HP rating would be important to a racer, to me it is less important than simply knowing where the "red line" is in each gear, and then what would be the best cruising speed (RPM's vs. MPH) for each gear.

As I said above, I feel really comfortable at 50 MPH in third gear. At this combination everything sounds great, smooth, quiet, and peaceful. All is right with the world!!

PS - don't sell these bikes short! They know . . . when they are being abused or loved!!! Grin

Back to top

"The difference between death and taxes is that death doesn't change every time congress meets." - Will Rogers

IP Logged

Ruttly Serious Thumper Offline Thumpers Rule Posts: 5112 Manteca , CA Gender:	Re: 5000 rpm safe? Reply #77 - 01/07/17 at 14:34:40 Oh my , now we have the "Savage Whisperer"
Back to top	The Topic Terminator IP Logged

Kris01 Serious Thumper Offline Eat, sleep, RIDE! Posts: 3767 Tennessee Gender:	Re: 5000 rpm safe? Reply #78 - 01/07/17 at 18:31:31 piedmontbuckeye wrote on 01/07/17 at 12:02:38: I feel really comfortable at 50 MPH in third gear. That seems a little fast for 3rd. I'm in 5th by the time I hit 50.
Back to top	There's no problem that a full tank of gas and a sunny day can't fix! 2008 S40, Rotella T 15W-40 w/ZDDP added, Dyna, 140/90-15, Battery Tender Jr., Seat lift, #52.5/150/3 washers, Raptor IP Logged

batman

Serious Thumper

Offline

SuzukiSavage.com
Rocks!

Posts: 3806
osceola new york
Gender: male

Re: 5000 rpm safe?
Reply #79 - 01/07/17 at 19:20:14

I agree with Kris,4th or 5th gear wood be quieter and more peaceful,save gas and be closer to peak torque. Kris 0 torque =0 rpm =0hp and as for those early motors that turned 300 rpm,they made about 15 hp, but 260ftlbs of torque,alot of these were used in boats at the turn of the last century where props of large size 25 to 30 inches turning at 300 rpm had high efficiency (only about 5% prop slip)so could push vessels 9ftwide by 36ft long and around 7500lbs at displacement speeds of around 10mph burning very little fuel.but many of these boats caught out in bad weather hid out behind islands or points of land until storms passed because they had no reseve power or speed. Dave steam has an expansion rate of up to 700-1 it's not an internal combustion engine your talking apples to oranges.

Back to top

« Last Edit: 01/07/17 at 21:43:26 by batman »

my old work mates called me MacGyver

IP Logged

eau de sauvage

Serious Thumper

Offline

Posts: 2565
Queensland
Gender: male

Re: 5000 rpm safe?
Reply #80 - 01/08/17 at 02:39:27

How true, take the Wärtsilä-Sulzer RTA96-C for example, at only 102 RPM it produces 107,000 hp yet manages over 5 1/2 million ft/lbs of torque.

https://en.wikipedia.org/wiki/Wärtsilä-Sulzer_RTA96-C

Dave wrote on 01/07/17 at 11:08:07:

A low rpm engine will still make HP, and it will still have torque.......however the torque value in ft/lbs will be a larger number than the HP value.

Back to top

MAGA! Make the Assholes Go Away

IP Logged

piedmontbuckeye

Senior Member

Offline

Go Bucks!

Posts: 496
Easley, SC
Gender: male

Re: 5000 rpm safe?
Reply #81 - 01/08/17 at 07:58:04

Kris01 wrote on 01/07/17 at 18:31:31:

piedmontbuckeye wrote on 01/07/17 at 12:02:38:

I feel really comfortable at 50 MPH in third gear.

That seems a little fast for 3rd. I'm in 5th by the time I hit 50.

I'm not sure why, because based on that RPM vs Speed chart on the first page, 50 MPH would put me about 1,000 RPM's less than peak HP while being in 4th or 5th by 50 mph would put the RPM's in my mind too low for that speed -around 2,000 less than peak HP.

I know that that combination (50 MPH and 3rd gear) sound good and like it is straining nothing.

I would like to hear what others do. What are their gear/speed when cruising in various conditions (for example, I would never cruise at 50 MPH on an interstate!).

Back to top

"The difference between death and taxes is that death doesn't change every time congress meets." - Will Rogers

IP Logged

Kris01 Serious Thumper Offline Eat, sleep, RIDE! Posts: 3767 Tennessee Gender:	Re: 5000 rpm safe? Reply #82 - 01/08/17 at 12:37:02 You want to travel in the highest gear possible that doesn't lug the engine. That way you burn less gas, there's less wear and tear on the engine, it won't overheat, less chance of over-stressing parts, etc, etc, etc.... You don't NEED to cruise at max torque or hp RPMs.
Back to top	There's no problem that a full tank of gas and a sunny day can't fix! 2008 S40, Rotella T 15W-40 w/ZDDP added, Dyna, 140/90-15, Battery Tender Jr., Seat lift, #52.5/150/3 washers, Raptor IP Logged

eau de sauvage

Serious Thumper

Offline

Posts: 2565
Queensland
Gender: male

Re: 5000 rpm safe?
Reply #83 - 01/08/17 at 12:42:54

@piedmonkey, if I was on a cruisey type of road I'd be in 4th or 5th at 80/kph, (50mph) if I was street riding I'd be in either 3rd or 4th, although most probably 4th if I'm in a sporty mood then I might be in 3rd. Either is fine though, it just feels more relaxing in 4th at that speed but 3rd is fine too. 5th gear is more of an overdrive on the s40.

Back to top

MAGA! Make the Assholes Go Away

IP Logged

Kris01 Serious Thumper Offline Eat, sleep, RIDE! Posts: 3767 Tennessee Gender:	Re: 5000 rpm safe? Reply #84 - 01/08/17 at 14:02:37 50 mph in 3rd is a little over 4300 RPMs. In 5th, it's a little over 3300. That's not too low to cruise in 5th. You'd be doing yourself a favor to shift!
Back to top	There's no problem that a full tank of gas and a sunny day can't fix! 2008 S40, Rotella T 15W-40 w/ZDDP added, Dyna, 140/90-15, Battery Tender Jr., Seat lift, #52.5/150/3 washers, Raptor IP Logged

piedmontbuckeye Senior Member Offline Go Bucks! Posts: 496 Easley, SC Gender:	Re: 5000 rpm safe? Reply #85 - 01/08/17 at 14:22:38 Kris01 wrote on 01/08/17 at 14:02:37: 50 mph in 3rd is a little over 4300 RPMs. In 5th, it's a little over 3300. That's not too low to cruise in 5th. You'd be doing yourself a favor to shift! But it sounds so good! Point well taken! I will try for a while when weather warms up a bit, and then re-program my brain!
Back to top	"The difference between death and taxes is that death doesn't change every time congress meets." - Will Rogers IP Logged

batman Serious Thumper Offline SuzukiSavage.com Rocks! Posts: 3806 osceola new york Gender:	Re: 5000 rpm safe? Reply #86 - 01/08/17 at 17:39:57 But it sounds so good! 25% more Heat ,25% more wear, and 20% less mileage ,doesn't sound so good to me.I would expect to do oil changes, valve adjustments,and cam chain inspection 25% earlier as well.
Back to top	my old work mates called me MacGyver IP Logged

IslandRoad

Serious Thumper

Offline

It doesn't vibrate,
it purrs!

Posts: 1147
The Kiewa Valley, Australia
Gender: male

Re: 5000 rpm safe?
Reply #87 - 01/08/17 at 18:24:32

Someone talking in kph! ... ah, it's so ... much like home ☺

I find 5th a tad under-revved for 80 kph. I usually sit in 4th - especially since receiving some feedback in another thread.

60 kph (this is a common speed limit here in Aus for roads that run through the main part of a town) always feels to me like it's right between 3rd and 4th gear.

eau de sauvage wrote on 01/08/17 at 12:42:54:

@piedmonkey, if I was on a cruisey type of road I'd be in 4th or 5th at 80/kph, (50mph) if I was street riding I'd be in either 3rd or 4th, although most probably 4th if I'm in a sporty mood then I might be in 3rd. Either is fine though, it just feels more relaxing in 4th at that speed but 3rd is fine too. 5th gear is more of an overdrive on the s40.

Back to top

S40, 2014, Dyna, Raptor, 52.5/152.5, spacer mod, sea level, cat-eye LED tail light, bullet style halogen turn signals, 'Superbars' with custom 40mm risers, modified stock seat, Metzeler tyres.

IP Logged

Dave

YaBB Moderator
ModSquad

Offline

SuzukiSavage.com
Rocks!

Posts: 18101
Camp Springs, Kentucky
Gender: male

Re: 5000 rpm safe?
Reply #88 - 01/09/17 at 03:34:52

batman wrote on 01/07/17 at 19:20:14:

Dave steam has an expansion rate of up to 700-1 it's not an internal combustion engine your talking apples to oranges.

The example wasn't intended to compare steam to gas......it was intended as an example of how a low rpm engine can make a lot of torque - even though the HP numbers are low in comparison. The calculations to convert rpm x torque into HP still work - even if the engine will never get up to 5,252 rpm.

I couldn't find an example of a low rpm gasoline engine with listed ratings for HP/torque at low rpm, as most modern gasoline engines get their HP at higher rpm, and using a diesel engine would have brought a similar apples/orange situation.

Back to top

Someday I will be old......But not today!

IP Logged

batman Serious Thumper Offline SuzukiSavage.com Rocks! Posts: 3806 osceola new york Gender:	Re: 5000 rpm safe? Reply #89 - 01/11/17 at 11:38:23 Dave that's why I talked about boats ,you could research William Garden's boat Tlingit for an example 3 cyl. gas engine 30hp @800rpm in a boat 7.5' wide 56' long. '
Back to top	my old work mates called me MacGyver IP Logged