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[steve1911]

Ok - let's say you just added some pipes, high-flow air-filter, and a SERT.  You have your favorite mechanic dyno tune your bike and you get 101 hp and 119 torque.

So here's the question:  What if you told your mechanic to tune for torque without regard to the hp curve.  How much more torque could you get?  (I don't even know if this is a valid question, but I thought I would ask just the same)

[SPIDERMAN]

Ok - let's say you just added some pipes, high-flow air-filter, and a SERT.  You have your favorite mechanic dyno tune your bike and you get 101 hp and 119 torque.

So here's the question:  What if you told your mechanic to tune for torque without regard to the hp curve.  How much more torque could you get?  (I don't even know if this is a valid question, but I thought I would ask just the same)

First off, if you've got almost 20 more ftlbs of TQ than you do HP you're already tuned for TQ Normally it's 10 or less. Is it a valid question. Yes, but given the paremeters you impose (Breather/pipes/SERT) not a realistic one. To do what you're talking about would involve a cam change with cams specifically ground to a TQ profile. There's a book out there called I belive The V-Twin High Guide to High Performance or something similar. It's a softcover book of about 250 pages or so. Great source of information on all of the variables involved with building up motors. Maybe somebody else will see this thread and will be able to quote you the exact name of the book. I see it advertised every so often in some of the bike mags.

B B

[steve1911]

Well, I was using the figures PHAZE got on his SERK after those modifications, so they are probably feasible.  But that's not really the point - my question is, if you can get 119 torque, while tuning for overall performance, how much more could you get if torque was the only goal?

[Tros]

First off, if you've got almost 20 more ftlbs of TQ than you do HP you're already tuned for TQ Normally it's 10 or less. Is it a valid question. Yes, but given the paremeters you impose (Breather/pipes/SERT) not a realistic one. To do what you're talking about would involve a cam change with cams specifically ground to a TQ profile. There's a book out there called I belive The V-Twin High Guide to High Performance or something similar. It's a softcover book of about 250 pages or so. Great source of information on all of the variables involved with building up motors. Maybe somebody else will see this thread and will be able to quote you the exact name of the book. I see it advertised every so often in some of the bike mags.

B B

Talkin' 'bout this one?

The first volume is available on amazon $99.53

http://www.amazon.com/s/ref=nb_ss_gw/103-8897139-7863039?url=search-alias%3Daps&field-keywords=D.+William+Denish+&Go.x=11&Go.y=8

The other two are not.  

[Seegarsmkr]

Ok so I'm thinkin' 119 ft/lbs TQ and you want MORE!!! Are you planning on pulling your 40 footer behind your bike?  Correct me if I am wrong, but if the discrepancy between TQ and HP is too great you will be up/down tap dancing like Fred Estaire to keep your revs in the max TQ range because there will be a noticeable drop in power if you rev too high and the drop is too great from TQ to HP. I think that the goal should be a happy marriage between the HP and TQ with TQ being the male and the higher, more desirable number but only with a strong partner to back it up.  Care to comment V,   JK in the analogy but I should think that more than a 20 drop would be noticeable and not desirable.

$.02 from the 

Seegarz

[Puzzled]

How much is a number that can't be set as there are to many parameters. Can it be done, yes. Since TQ is low end and HP is top end (for the most part) a bike could be tuned for low end with no great attention to top end.

So what are you building for a TQ monster?

[nidan]

As hp is a function of torque x rpm /5252  "tuning " for torque is really looking at a cam that produces most of the power in the low to mid rpm ranges.  If a cam produces a very flat torque curve across the entire range , hp will rise as rpm does.

[mr_magoo]

One thing to figure in is reliablity.

[JCZ]

There's a previous member of this site (I only say "pevious" because I haven't saw him post here in a couple of years) who had a motor built for torque.  Click on this link and look at Gary's "Tree Stump Puller"............    http://www.bcheads.com/dyno.htm

[RJ749]

There's a previous member of this site (I only say "pevious" because I haven't saw him post here in a couple of years) who had a motor built for torque.  Click on this link and look at Gary's "Tree Stump Puller"............    http://www.bcheads.com/dyno.htm

Looks like he got it done too.  Thanks for the link JC.

[SPIDERMAN]

Talkin' 'bout this one?

The first volume is available on amazon $99.53

http://www.amazon.com/s/ref=nb_ss_gw/103-8897139-7863039?url=search-alias%3Daps&field-keywords=D.+William+Denish+&Go.x=11&Go.y=8

The other two are not.  

Tros,
         That's the one. I consider this " Must Reading " for anyone claiming to be a gearhead.

B B

[SBB]

Tros,
         That's the one. I consider this " Must Reading " for anyone claiming to be a gearhead.

B B

Nancy, Nancy!
Christmas present alert!

 

[steve1911]

We all talk about how nice and flat our torque curves are - and that is good because it mean you have torque at the low end, and the high end.  What I am proposing is a torque that starts off like that - high everywhere, but just gets higher, even if the result isn't so "flat".

[SPIDERMAN]

We all talk about how nice and flat our torque curves are - and that is good because it mean you have torque at the low end, and the high end.  What I am proposing is a torque that starts off like that - high everywhere, but just gets higher, even if the result isn't so "flat".

You just described the curves of what I mean when I talk about dyno charts showing very quick elapsed times. The curves jump up right off the bat and then climb a little more to their peaks.

[steve1911]

That's right.   I am looking for acceleration, not top speed, but I don't want to get it by changing gear ratios (like with drive sprockets) because that screws up highway speed cruising.  I don't care if my bike goes over 110 mph, as long as it gets there damn fast, and still cruises at a reasonable rpm at 70 mph.