Potato Potato Potato

[RoadGlideRider]

Originally Posted by Still Grumpy

What ever happened to that Harley sound.
I have it on my 2005 Fat Boy. (carburated)
But my stock Road Glide sounds like my next door neighbor's Honda Shadow.. ..


Is it that Fuel Injected engines will not have this low idle and thus will never have the signature Potato Potato Potato sound that I grew up loving ?

Originally Posted by JD HD

Basically, yes. A cam will give it a lope or chop to the idle, but it will never sound like a shovel.

The sound at Idle changed with the introduction of the EVO motor. When the EVO was designed, it had tighter specifications. This required higher oil pressure to get the oil to critical parts.
If you check the Service manuals from the introduction of the EVO to current models, it will say that the RPM at idle is required to be set at a minimum of 1000 RPM. If set at a lower RPM it can cause engine damage.

If you have a carburetor on a EVO or Twin Cam, the RPM can be set below the 1000 threshold. But, over time, the damage to the motor is there. With the introduction of EFI models, the RPM can not be lowered below 1000 RPM, Unless you have an aftermarket ECM. Some have the capability to lower the RPM below 1000. But this number is small because of the liability of using their module and causing engine damage.

The bottom line is if you want the Potato, Potato sound, you must have the older model motor. Then you will have the problems that came along with the loose specifications.

[hotrodad]

Originally Posted by Still Grumpy

What ever happened to that Harley sound.
"my stock Road Glide sounds like my next door neighbor's Honda Shadow".. ..

well i have to say all harleys with stock exhaust DOES sound like hondas. In fact I have heard louder hondas; and THAT is offensive!

A cam change, intake/exhaust and the right map will give you the potato potato, ALMOST. All Harley motors sound distinctively "Harley" and yet have a individual sound specific to their model. Just wait for the next generation motor after the twinkie and see what it sounds like. As long as its not a sowing machine!

[smitty901]

Dual cams, faster idle all smoth out the slow looping Idle the EVO was the end of that.
Slowing idle down on the TCto get some of it back is a bad idea

[fitter_rob]

I have a Thundermax on my 06 RG and have the idle set about 850rpm. It still puts out about 20+ oil pressure and about 13 volts at idle. The lower idle sounds better and the bike doesn't get hot as fast sitting in traffic. Been running it that way for almost a year now with no problems.

[SharkNose]

With the intro of FI and totally separate intake paths, that potato sound is lost unless you're running some wild engine mods (cams with alot of overlap, etc). The old carb/intake manifolds caused a lot of weird air/gas flow pulses (read inefficient) thru the intake path to combustion chamber. A lower idle RPM and those inefficiencies caused the famous lope at idle.

I first noticed the lose of the sound on my 1996 FLTRI EVO that came with factory FI. I really missed the sound but liked the easier starting, no more fouled plugs, better MPG, etc that FI brought.

But I thought by now some ultra-smart EFI tuner guys would have figured out how to re-create that sound at idle, without losing the efficiencies gained at all other off-idle RPMs. Something like the high-temp/parade mode, but a mode that mimic-ed the old lope. If someone came out with that mod he'd made lotsa money!

[RoadGlideRider]

Originally Posted by fitter_rob

Been running it that way for almost a year now with no problems.

Yet.... But will you get 100,000+ miles without any problems related to lack of lube??
On my 98 Ultra I had over 158,000 miles when it was totaled without any engine work. I knew it was tired but still ran good.

But it is your motor and you are welcome to run it as you see fit. Enjoy.

[allofus81]

Originally Posted by fitter_rob

I have a Thundermax on my 06 RG and have the idle set about 850rpm. It still puts out about 20+ oil pressure and about 13 volts at idle.

U might want to look into replacing your oil pressure gauge..... It is way off!!! 20 psi at cold idle maybe but in 80 degree traffic bet its under 5 psi and that's when u need the oil up there! Turn it back up or have problems.

[rageglide]

Advanced timing, faster idle plus EFI means little to no reversion. No reversion, no lope...

EFI is ALL about meeting emissions. A high idle with lots of advance is cleaner burning than a low idle, retarded ignition timing and carbs pollute like crazy.

Lope went away in Harleys when we got factory electronic ignitions. With points you idled at roughly your static timing and timing only advanced with RPM. Electronic ignitions use VOES or MAP sensor to adjust timing for load. VOES only had two maps, theres no in between. MAP has variability so you can get more steps in the timing changes.

No load is max advance, best mileage, smooth fast idle... You don't have a "Load" condition when at Idle, so you get no lope. But if you have a VOES you could put a toggle switch inline and when you flip it at idle you'd get lope... Of course that's kinda silly... but I knew a guy who thought it was kinda fun... he missed the lope from his shovelhead.

800-900rpm idle sounds Very different when you don't have timing advanced, so you would get a more satisfying idle... but it'd be a lot of work fiddling with EFI maps to accomplish this with no real gain and probably far more negative driveability issues...

And my Evo's have idled with 0 oil pressure (flickering oil warning light) with NO problems... have never lost a Harley bottom end due to lack of oiling... Roller bearings require very very little oil to run happily for many many miles.

Oil plays a far bigger role in heat management than in keeping our roller bearings wet. And Twinkies' need all the heat management help they can get.

[rageglide]

Oh yeah... my buddies '85 FLHP shovelhead (one of a couple hundred built) with electronic ignition and voes sounded just like any stock Evo... no potato potato potato

[Xaran]

Originally Posted by Still Grumpy

What ever happened to that Harley sound.
I have it on my 2005 Fat Boy. (carburated)
But my stock Road Glide sounds like my next door neighbor's Honda Shadow.. ..


Is it that Fuel Injected engines will not have this low idle and thus will never have the signature Potato Potato Potato sound that I grew up loving ?

Fuel injection and the fact that the Twin Cam has to idle at a higher RPM to maintain oil pressure