M8 power output

[BigT]

I'm seeing some of these dyno runs from the 117" M8 making a little under 125 hp/tq with 11:1 compression. I'm making pretty the same power with my Twin Cam with the bolt on 110 cylinders and basic head work, Tman 577 cams and less compression. I doubt my heads flow as well as the 4 valve head. Kind of wonder why we're not seeing the M8 making more power.

[hd06]

 This is the first year for M8 things will get better.

[trex]

With the 4 valve heads I wonder what an over square M8 would run like. 117 size bore with early 88in. TwinCam stroke of 4in. Appropriate cam and 11-1m comp. Seems like it would be a screamer

[SoZo]

Star Power 117 build...

[SoZo]

Fuel Moto 117

[Don D]

 I doubt my heads flow as well as the 4 valve head
But they probably have better velocity and have enough flow to feed the motor and not choke it in the RPM range it runs

[Matt C]

A big advantage is mixture motion (tumble vs. swirl).
That, and the valve train is lighter, favoring higher RPMs.
A 2V head will still move enough air. 

[Don D]

Swirl, 2 valve, better for lower rpm motor, 4 valve tumble, great for higher rpms and over camping will send low end torque in the dumpster in a hurry

[harleytuner]

Here's a 114 I did.  This was before he took it in for a new oil pump.  It was sumping pretty bad.  I could drain the sump, make 4 pulls on the dyno and get 18oz back out of the sump.  Woods cams. Head Hoggers heads[attachimg=1]

[BigT]

Which Woods cam?

[harleytuner]

Which Woods cam?

M8777's

[Matt C]

You don't need allot of cam, b/c the valve curtain area(s) (added together) are plenty big.
So now, will we be able to use these heads? Will the bottom end take 7,8 or 9000 rpm? I doubt it.

[1FSTRK]

I'm seeing some of these dyno runs from the 117" M8 making a little under 125 hp/tq with 11:1 compression. I'm making pretty the same power with my Twin Cam with the bolt on 110 cylinders and basic head work, Tman 577 cams and less compression. I doubt my heads flow as well as the 4 valve head. Kind of wonder why we're not seeing the M8 making more power.

No one is making large improvements with the M-8 over the Twin cam when it comes to HP/CI or HP/CFM. The the over all intake design as delivered from HD just is not that great. Many mistakenly believe that 50 percent more air flow was all that was needed. I also do not think two valves, two springs sets, and a bigger rockers weight less than the single valve twin cam setup. All that load is now on the same old C lifter that was no good in the twin cam.

[SoZo]

I'm seeing some of these dyno runs from the 117" M8 making a little under 125 hp/tq with 11:1 compression. I'm making pretty the same power with my Twin Cam with the bolt on 110 cylinders and basic head work, Tman 577 cams and less compression. I doubt my heads flow as well as the 4 valve head. Kind of wonder why we're not seeing the M8 making more power.

No one is making large improvements with the M-8 over the Twin cam when it comes to HP/CI or HP/CFM. The the over all intake design as delivered from HD just is not that great. Many mistakenly believe that 50 percent more air flow was all that was needed. I also do not think two valves, two springs sets, and a bigger rockers weight less than the single valve twin cam setup. All that load is now on the same old C lifter that was no good in the twin cam.

The potential is there... The current intake and exhaust offerings are not capable of flowing what the heads can flow. The heads with professional expert porting (CNC Heads flow almost NO better then stock)  with stock valve sizes can make big improvements in the exhaust port and good gains in the intake. Larger valves make big strides... Cam profile is totally different, overlap needs to start at 100mm lift to get things flowing. There is no Borizilla size exhaust yet.. Fuel Moto is working on large stepped 2 into 1 which will greatly enhance exhaust savaging and HP capability.  The screeming Eagle Throttle Body and intake have a bad design where one cylinder flows 55cfm less the the other(I forget front or rear){the SE intake can be worked by porting to flow more} HP INC has a better 62mm setup which flows substantially more. ALSO there are not many high compression pistons out yet... most are flat top @10.5:1. 

[1FSTRK]

I'm seeing some of these dyno runs from the 117" M8 making a little under 125 hp/tq with 11:1 compression. I'm making pretty the same power with my Twin Cam with the bolt on 110 cylinders and basic head work, Tman 577 cams and less compression. I doubt my heads flow as well as the 4 valve head. Kind of wonder why we're not seeing the M8 making more power.

No one is making large improvements with the M-8 over the Twin cam when it comes to HP/CI or HP/CFM. The the over all intake design as delivered from HD just is not that great. Many mistakenly believe that 50 percent more air flow was all that was needed. I also do not think two valves, two springs sets, and a bigger rockers weight less than the single valve twin cam setup. All that load is now on the same old C lifter that was no good in the twin cam.

The potential is there... The current intake and exhaust offerings are not capable of flowing what the heads can flow. The heads with professional expert porting (CNC Heads flow almost NO better then stock)  with stock valve sizes can make big improvements in the exhaust port and good gains in the intake. Larger valves make big strides... Cam profile is totally different, overlap needs to start at 100mm lift to get things flowing. There is no Borizilla size exhaust yet.. Fuel Moto is working on large stepped 2 into 1 which will greatly enhance exhaust savaging and HP capability.  The screeming Eagle Throttle Body and intake have a bad design where one cylinder flows 55cfm less the the other(I forget front or rear){the SE intake can be worked by porting to flow more} HP INC has a better 62mm setup which flows substantially more. ALSO there are not many high compression pistons out yet... most are flat top @10.5:1.

Well the heads already flow 50% more than the Twincam heads and make the same HP/CI so I do not think bigger valves and even more flow is a cure. The rest of the parts do play in but just go to show that slapping four valves on something is not the game changer.  Yes they will with time catch up but it will in the end not be about CFM numbers from the heads.

[hd06]

 M8 is only little over a year old look how far T.C. have come in 18 years and they started with 88 C.I. M8 will only better.

[1FSTRK]

I may not even be riding in 18 more years 

[SoZo]

I may not even be riding in 18 more years 

Tri Glide.... with a 124M8... woot

[1FSTRK]

I may not even be riding in 18 more years 

Tri Glide.... with a 124M8... woot

If we take the emotion out and disregard the "newer is always better" philosophy we are left with the numbers. For my money, if you want great reliable power in the couple years take the amount of the sales tax on a new bike, add the amount of money you lose on any new vehicle when you drive it off the lot and put that into any Twin cam and you will have a great reliable motorcycle that that you can ride today.  I have a 4" stroke 5speed Road king and a 43/8" stroke 6speed Softail and both have been delivering trouble free miles at over 1.2 HP/CI for ten years. 

Want a new bike, fine buy one they are pretty. Want a new bike because the new motor is a more advanced, better performance platform, don't kid yourself there is different, and there is better, the two words do not mean the same thing. We had this same discussion when I posted here that the 120R would give average street HP with all the PMS and maintenance of a race engine and that made 120R fans all upset but was true.

As stated someone will figure out what needs to be changed in a M-8 to make it what it should have been from the beginning but it has not happened yet and may be a while with the learning curve that comes with a low rpm, long stroke, 4 valve head design but until then for the sake of the "Tech" in Harley Tech Talk let us be honest about what M-8 is and is not in its present state.

[BigT]

  I think the M8 is a better performance platform than earlier motors. The stock heads flow in the 300+ range, wider cylinder/ head bolt spacing allowing for future bigger bores. I've talked to a few head porters and hear the same thing that it's just going to take some time for the after-market to develop cams and exhaust systems. My M8 is is the the smoothest running motor vibration wise that I ever owned in 40 years of riding just a slug over 3000 rpm at this point.

[Larry757]

What no one understands when it comes too the M8 power is when and how it makes it. M8 Makes it now doesn't have to "come on" it's instant. Less power quicker will accelerate quicker than more power later. Passing after the finish line doesn't matter!!

[BigT]

I'm hoping S&S comes out with M8 "bolt-on" cylinders with steel liners this winter! It looks like the cases will take a 4.250 bore using resleeved cylinders (Hot Shot Motorworks) Not sure how big you could go with the much thinner steel liners.  131" would be nice!

[HD/Wrench]

http://www.harleytechtalk.com/htt/index.php?topic=101154.0

[irishrover]

Limiting factor on big power on any Harley motor is the 45 degree cylinder angle. You just can't turn the RPM's needed to make HP. YOU can make a lot of Torque, now before you all tell me to F-off look at what you have. 131inch motor with 135-150 hp with 130-140 ft lbs, now that's a motor that is definitely not what I would call a daily driver, it won't be smooth and I don't think you would want to ride it two up to California from the east coast, But that's not my point Now look at a Ducati V twin 90 degree cylinder angle 1200 cc or basically 75 cubic inches and there making in the case of my multistrada 160 hp with around 110 torque and and it runs as smooth as a babies axx . All im saying is they are what they are, so injoy it I wasted so much money on my roadking and its still a rough riding slow pig compared to my Ducati. but its your dough 

[Hossamania]

You forgot to mention that the RoadKing weighs about 200 pounds more than the Multi, but looks much better doing it.....

[irishrover]

Well actually it weighs about 400 lbs more and as far as looks its apple and oranges, but what no one can take away from Harley is its ( my opinion its prehistoric looks) I get a kick out of the motor shake at idle, and that motor responds so well to relatively inexpensive improvements just changing the cams can give you 10-20 more hp and torque. I guess i'm just a little sour because I've spent so much money on the Harley chasing hp and riding comfort( talking shocks here ) That I feel I should have left it stock and road it because in stock form it traveled 70-80 all day long just like now and I spent well over 3000 in parts and luckily I did all the labor and saved probably another 3000, and after spending nearly a 1000 on rear shocks and the wife still needs an air hawk cushion I'm just real disappointed. I mean the bike cost 20,000 new and you have to spend minimum 5000 more (not counting labor) and it still don't compare to ride quality of my BMW RT or MY Ducati Multistrada So right now the Road king is designated to toy run duty's and posing duty's     

[sfmichael]

Well actually it weighs about 400 lbs more and as far as looks its apple and oranges, but what no one can take away from Harley is its ( my opinion its prehistoric looks) I get a kick out of the motor shake at idle, and that motor responds so well to relatively inexpensive improvements just changing the cams can give you 10-20 more hp and torque. I guess i'm just a little sour because I've spent so much money on the Harley chasing hp and riding comfort( talking shocks here ) That I feel I should have left it stock and road it because in stock form it traveled 70-80 all day long just like now and I spent well over 3000 in parts and luckily I did all the labor and saved probably another 3000, and after spending nearly a 1000 on rear shocks and the wife still needs an air hawk cushion I'm just real disappointed. I mean the bike cost 20,000 new and you have to spend minimum 5000 more (not counting labor) and it still don't compare to ride quality of my BMW RT or MY Ducati Multistrada So right now the Road king is designated to toy run duty's and posing duty's   

there's some harsh truth in that   

[PoorUB]

Yep, no reason HD can not spend a little R&D on some rear shocks for the baggers. The stock ones are crap. Go ride some of the other brands and it makes you wonder where the nearly $30k went. Plus the engine is fine for 50-60 MPH, but hit the interstate and try to make some time and it doesn't make it in stock form.

[Nastytls]

They have no reason to spend any money on R&D. Unlike other manufacturers, HD knows people will accept glaringly inferior quality and still consider it "the best". They also know if they offer accessories people will happily throw down even more cash, despite it still being inferior to aftermarket parts. No other company would get away with it, but as long as people continue to line up and buy them they will never change.

[sfmichael]

They have no reason to spend any money on R&D. Unlike other manufacturers, HD knows people will accept glaringly inferior quality and still consider it "the best". They also know if they offer accessories people will happily throw down even more cash, despite it still being inferior to aftermarket parts. No other company would get away with it, but as long as people continue to line up and buy them they will never change.

pretty much 

[BigT]

I see a new 133 cu in build by Star Power making 176 hp & 157 tq. Not sure of the specifics of the build but it was still building power at 7k

[HD/Wrench]

saw that as well Was going to give George a call about that impressive for sure .

[1FSTRK]

I see a new 133 cu in build by Star Power making 176 hp & 157 tq. Not sure of the specifics of the build but it was still building power at 7k

Did someone say way back in the beginning if you could grow the engine big enough and spin it fast enough you may start to utilize the size of the ported factory M-8 heads?

[Nastytls]

How much time/durability could you honestly expect with one of these dinosaurs spinning to 7k... Looking at the power curve on their dyno sheet it doesn't really look like it's worth it at all.

[PoorUB]

Maybe if HD stepped up the technology a bt, maybe a lot, and built a decent engine. 7,000 RPM is nothing. My BMW 1200 opposed twin redlines at 10,000.

[Ohio HD]

45° degree v-twins are not high RPM motors. That's why companies like Ducati use 90° v-twins, and the Honda V45  Magna, they were 90° v-4's. Yamaha V-Max, 65° and even Kawasaki v-twins went to 50° angle. Horizontally opposed twins are turnips to peas in comparison to a 45° v-twin.

[Nastytls]

I have a 1200 Boxer too, to be 100% fair they only have 2.3" of stroke which makes higher rpm much easier.

[yobtaf103]

I'm hoping S&S comes out with M8 "bolt-on" cylinders with steel liners this winter! It looks like the cases will take a 4.250 bore using resleeved cylinders (Hot Shot Motorworks) Not sure how big you could go with the much thinner steel liners.  131" would be nice!

Looks like this winter!

[PoorUB]

45° degree v-twins are not high RPM motors. That's why companies like Ducati use 90° v-twins, and the Honda V45  Magna, they were 90° v-4's. Yamaha V-Max, 65° and even Kawasaki v-twins went to 50° angle. Horizontally opposed twins are turnips to peas in comparison to a 45° v-twin.

Who said they had to stay with a 45 degree V? Of course they will, because they have always done it that way!

[Hossamania]

45° degree v-twins are not high RPM motors. That's why companies like Ducati use 90° v-twins, and the Honda V45  Magna, they were 90° v-4's. Yamaha V-Max, 65° and even Kawasaki v-twins went to 50° angle. Horizontally opposed twins are turnips to peas in comparison to a 45° v-twin.

Who said they had to stay with a 45 degree V? Of course they will, because they have always done it that way!

They went away from it with the Vrod and look how that worked out.

[Ohio HD]

45° degree v-twins are not high RPM motors. That's why companies like Ducati use 90° v-twins, and the Honda V45  Magna, they were 90° v-4's. Yamaha V-Max, 65° and even Kawasaki v-twins went to 50° angle. Horizontally opposed twins are turnips to peas in comparison to a 45° v-twin.

Who said they had to stay with a 45 degree V? Of course they will, because they have always done it that way!

If they want to sell them they'll keep them 45°. The only HD owners that would really buy some other HD motor configuration, doesn't want an HD anyway. HD goes away from a 45° and they cease to be HD's.

[sfmichael]

45° degree v-twins are not high RPM motors. That's why companies like Ducati use 90° v-twins, and the Honda V45  Magna, they were 90° v-4's. Yamaha V-Max, 65° and even Kawasaki v-twins went to 50° angle. Horizontally opposed twins are turnips to peas in comparison to a 45° v-twin.

Who said they had to stay with a 45 degree V? Of course they will, because they have always done it that way!

If they want to sell them they'll keep them 45°. The only HD owners that would really buy some other HD motor configuration, doesn't want an HD anyway. HD goes away from a 45° and they cease to be HD's.

nailed it

[PoorUB]

45° degree v-twins are not high RPM motors. That's why companies like Ducati use 90° v-twins, and the Honda V45  Magna, they were 90° v-4's. Yamaha V-Max, 65° and even Kawasaki v-twins went to 50° angle. Horizontally opposed twins are turnips to peas in comparison to a 45° v-twin.

Who said they had to stay with a 45 degree V? Of course they will, because they have always done it that way!

If they want to sell them they'll keep them 45°. The only HD owners that would really buy some other HD motor configuration, doesn't want an HD anyway. HD goes away from a 45° and they cease to be HD's.

Pretty much what the masses will think! Why change? It has always been done ths way!

As for the Vrod, I don't believe it was the engine, it was the motorcycle. Good engine, wrong frame, but he Harley masses run from technology so it probably wouldn't have been accepted no matter the HP , torque or frame it was installed into.

I am curious  to see what Harley riders will be buying in th next ten-twenty years.

[Nastytls]

I am curious  to see what Harley riders will be buying in th next ten-twenty years.

Harley riders will all be dead or in nursing homes in the next 20 yrs so HD won't need to worry about making them happy anymore because there won't be any...

[Ohio HD]

I am curious  to see what Harley riders will be buying in th next ten-twenty years.

Harley riders will all be dead or in nursing homes in the next 20 yrs so HD won't need to worry about making them happy anymore because there won't be any...

   

[98fxstc]

45° degree v-twins are not high RPM motors. That's why companies like Ducati use 90° v-twins, and the Honda V45  Magna, they were 90° v-4's. Yamaha V-Max, 65° and even Kawasaki v-twins went to 50° angle. Horizontally opposed twins are turnips to peas in comparison to a 45° v-twin.

Who said they had to stay with a 45 degree V? Of course they will, because they have always done it that way!

If they want to sell them they'll keep them 45°. The only HD owners that would really buy some other HD motor configuration, doesn't want an HD anyway. HD goes away from a 45° and they cease to be HD's.

Pretty much what the masses will think! Why change? It has always been done ths way!

As for the Vrod, I don't believe it was the engine, it was the motorcycle. Good engine, wrong frame, but he Harley masses run from technology so it probably wouldn't have been accepted no matter the HP , torque or frame it was installed into.

I am curious  to see what Harley riders will be buying in th next ten-twenty years.

Harleys have had changing and improving technology over the years and the masses have followed.

The M8's don't sound like Harleys and are looking less and less like Harleys, and more and more like Jap and European bikes.
Not just more and more plastic, but styling as well.

Who knows where we will end up.

[DTTJGlide]

Seems like almost every thread on here turns to bashing HDs, maybe we should change the name to Harley Trash Talk. I know they're far from perfect, but I've got over 300K on 4 Harleys, 3 TCS & now a M8 with 37K & I've had very few major problems. The dreaded 1st year 99 RK with 82K, a 00 EG 110K, 88K that I put on & had to do hyd tensioner upgrade, 09 RG with 142K did comp upgrade about 80K & throwout bearing at 102K, 17 RG that needed the clutch switch replaced, it has 37K & I'm lucky again as no sumping & maybe 6 oz of trans migration in that time. All were modded, 3 TCs were 103s with cams & headwork, the M8 has been Stg 2 for the last 18.5K. I must just be lucky as he!!, just gets old reading all the crap, I expect it on the other sites, not so much on here, OK rant over, go back to whatever you were up to before.

[sfmichael]

45° degree v-twins are not high RPM motors. That's why companies like Ducati use 90° v-twins, and the Honda V45  Magna, they were 90° v-4's. Yamaha V-Max, 65° and even Kawasaki v-twins went to 50° angle. Horizontally opposed twins are turnips to peas in comparison to a 45° v-twin.

Who said they had to stay with a 45 degree V? Of course they will, because they have always done it that way!

If they want to sell them they'll keep them 45°. The only HD owners that would really buy some other HD motor configuration, doesn't want an HD anyway. HD goes away from a 45° and they cease to be HD's.

Pretty much what the masses will think! Why change? It has always been done ths way!

As for the Vrod, I don't believe it was the engine, it was the motorcycle. Good engine, wrong frame, but he Harley masses run from technology so it probably wouldn't have been accepted no matter the HP , torque or frame it was installed into.

I am curious  to see what Harley riders will be buying in th next ten-twenty years.

Now we'll never know...but I always wondered why they didn't try putting that stellar engine in a touring frame.

The technology is changing, just slowly. But I don't mind the pace. Just need a better suspension to satisfy me. I don't mind souping them up - I actually enjoy it. I wouldn't mind upgrading the suspension either, if they would just give us more to work with. We need 5-6 inches of suspension travel designed in from the factory...I'll spend the money on the better components.

Twin Cam engines can be made to run very well without megabucks invested and I think the M8 will prove to be even better as far as ROI, as they come with good heads from the factory - so no real need to spend $$ there unless you want to. Heck even the TC's can run damn good without doing the heads if you pick the other parts right. (and I'm a huge advocate of head porting)

[98fxstc]

Seems like almost every thread on here turns to bashing HDs, maybe we should change the name to Harley Trash Talk. I know they're far from perfect, but I've got over 300K on 4 Harleys, 3 TCS & now a M8 with 37K & I've had very few major problems. The dreaded 1st year 99 RK with 82K, a 00 EG 110K, 88K that I put on & had to do hyd tensioner upgrade, 09 RG with 142K did comp upgrade about 80K & throwout bearing at 102K, 17 RG that needed the clutch switch replaced, it has 37K & I'm lucky again as no sumping & maybe 6 oz of trans migration in that time. All were modded, 3 TCs were 103s with cams & headwork, the M8 has been Stg 2 for the last 18.5K. I must just be lucky as he!!, just gets old reading all the crap, I expect it on the other sites, not so much on here, OK rant over, go back to whatever you were up to before.

Certainly not "almost every thread on here turns to bashing HDs",
maybe almost every thread in the M8 section.

I have the impression that quite a few M8 owners are a bit precious when it comes to criticism of the M8s.

Most discussion on this site looks at recognizing and addressing design shortfalls in all models of bikes.
Owners of previous models are not in denial at being short changed by the bean counters at HD but get in and do something about it.

Quite large numbers of the 'new bike' buyers do not have the necessary level of technical expertise required to address these problems themselves and are dependent on the Dealers.
New bike warranty also plays a part in reluctance by owners to address these problems with improved aftermarket parts.

And warranty is important for a bike that may have design problems or is not reliable and dependable.

We shouldn't discuss design problems in a new model because M8 owners are a bit thin skinned ?

[Hossamania]

There is no perfect motorcycle, no perfect suspension, no perfect engine. We choose the brand and style that come closest to meeting those parameters. Mostly we choose the ones that make us happy every time we throw a leg over.
We always want them to be better.

The most rare of all Harley Davidsons is the one that is absolutely bone stock and completely unmodified in any little way.

[08flstf]

So, any more comments or new info on M8 power output? That was the title of this thread right?

[vincer77]

I'm seeing some of these dyno runs from the 117" M8 making a little under 125 hp/tq with 11:1 compression. I'm making pretty the same power with my Twin Cam with the bolt on 110 cylinders and basic head work, Tman 577 cams and less compression. I doubt my heads flow as well as the 4 valve head. Kind of wonder why we're not seeing the M8 making more power.

No one is making large improvements with the M-8 over the Twin cam when it comes to HP/CI or HP/CFM. The the over all intake design as delivered from HD just is not that great. Many mistakenly believe that 50 percent more air flow was all that was needed. I also do not think two valves, two springs sets, and a bigger rockers weight less than the single valve twin cam setup. All that load is now on the same old C lifter that was no good in the twin cam.

The potential is there... The current intake and exhaust offerings are not capable of flowing what the heads can flow. The heads with professional expert porting (CNC Heads flow almost NO better then stock)  with stock valve sizes can make big improvements in the exhaust port and good gains in the intake. Larger valves make big strides... Cam profile is totally different, overlap needs to start at 100mm lift to get things flowing. There is no Borizilla size exhaust yet.. Fuel Moto is working on large stepped 2 into 1 which will greatly enhance exhaust savaging and HP capability.  The screeming Eagle Throttle Body and intake have a bad design where one cylinder flows 55cfm less the the other(I forget front or rear){the SE intake can be worked by porting to flow more} HP INC has a better 62mm setup which flows substantially more. ALSO there are not many high compression pistons out yet... most are flat top @10.5:1.

Burns Stainless already makes two big pipes for M8s and have seen 131 builds near 180hp.  Check out Star Racing.

[sandrooney]

So far I like my 18 Heritage 114. Can't wait to pipe it and tune it. Just don't want to mess up the warranty or I already would have.

[sfmichael]

So far I like my 18 Heritage 114. Can't wait to pipe it and tune it. Just don't want to mess up the warranty or I already would have.

you can probably do that with HD stuff and retain the warranty

[sandrooney]

I am sure I can but the Harley slip on's will still have the cats in the mufflers and not really be that much different in sound or feel.
I wonder if I could go with some V&H and use the Harley tuner and still retain the warranty?
Thanks
SR

[Nastytls]

I am sure I can but the Harley slip on's will still have the cats in the mufflers and not really be that much different in sound or feel.
I wonder if I could go with some V&H and use the Harley tuner and still retain the warranty?
Thanks
SR

No you can't, unless you put the stock pipes back on before bringing it in for service you could.

[IronButt70]

I am sure I can but the Harley slip on's will still have the cats in the mufflers and not really be that much different in sound or feel.
I wonder if I could go with some V&H and use the Harley tuner and still retain the warranty?
Thanks
SR

No you can't, unless you put the stock pipes back on before bringing it in for service you could.

That can also depend on the dealer.

[sfmichael]

I am sure I can but the Harley slip on's will still have the cats in the mufflers and not really be that much different in sound or feel.
I wonder if I could go with some V&H and use the Harley tuner and still retain the warranty?
Thanks
SR

No you can't, unless you put the stock pipes back on before bringing it in for service you could.

A lot depends on the dealer...SR has bought several bikes from the same people and if I were them I would do it for him. Anyone in their right mind knows some exhaust and a performance map isn't going to hurt anything, and some people still have common sense. I don't know about a long journey out of state if one had to depend on another dealer - that may be tricky.
The whole warranty / EPA thing has gotten out of hand and I find it ridiculous. Doesn't matter what I think, I certainly know that. But dealers have been bending the rules in certain circumstances for years and I'm sure some will continue to do so.
FWIW my 2 of my 4 new bikes never had a warranty concern, and none ever had an engine related issue.

[Nastytls]

I am sure I can but the Harley slip on's will still have the cats in the mufflers and not really be that much different in sound or feel.
I wonder if I could go with some V&H and use the Harley tuner and still retain the warranty?
Thanks
SR

No you can't, unless you put the stock pipes back on before bringing it in for service you could.

That can also depend on the dealer.

Yes, you are correct. I was making a general statement regarding how HD is currently looking at things.

There are good dealers out there that won't f**k their customers and others that will. If I had to guess there are more that will vs. won't. My dealer knows what I have done to my M8 and are not reporting me to HD.

[sandrooney]

Will the super tuner adjust enough for the V&N 300 eliminator slip on's ?  I read it doesn't adjust for fuel.

[1FSTRK]

Will the super tuner adjust enough for the V&N 300 eliminator slip on's ?  I read it doesn't adjust for fuel.

It will adjust the fuel but no matter what it still adjusts to the very lean EPA air fuel ratios that are locked in.
This is a problem with stock power and more so when you open up the air in and air out because with more air and fuel you get even more heat at that same lean AFR. None of this adjusts the extreme timing numbers and when the heat goes up you will get even more detonation.
Will it keep the warranty and last until it expires, you bet, but when that warranty is up you own the POS and the damage is done then you fix it on your dime.

[sandrooney]

I have the 114 so it already has the hi flow A/C. I don't know if the map is different than the stock 107. It runs great and in no way do I feel the heat like I did on my TC. No detonation at all. I got no detonation on my TC either (Rushmore 103 box stock except for Street Cannons). My only concern with the warranty is the issues some M8's are having. I have not read about these issues on the softail so maybe I don't need to be so concerned. Do I roll the dice or not is the question?
Thanks

[DTTJGlide]

S&S has a set of slip ons with a hi flow cat that are EPA compliant, they have a sound clip on the billet tip model, they also have a slash cut for $449.95, they don't sound too bad, might be another option.

[sandrooney]

I'll take a look at them. Thanks

[hattitude]

I'm seeing some of these dyno runs from the 117" M8 making a little under 125 hp/tq with 11:1 compression. I'm making pretty the same power with my Twin Cam with the bolt on 110 cylinders and basic head work, Tman 577 cams and less compression. I doubt my heads flow as well as the 4 valve head. Kind of wonder why we're not seeing the M8 making more power.

If you're willing to go aftermarket, and warranty be damned (or expired) there are some shops making good power from the M8.. but of course, they are making big bore kits...

Fuel Moto is working on 124 Milwaukee Eight big bore kits, and show a dyno chart, reporting a max torque of 159.30