I'm losing sleep thinking this over, and I hate to admit it but it's as much a matter of affordability as anything.

I'm looking for big, bowel churning torque at lower rpms, HP is good too but torque is what makes riding fun for me.

My current setup is a stock 2004 1200 engine, stock carb with new jets and baffeld Santee exhaust.

I LOVE the thought of 88 cubes.... But if I can get hgh torque numbers with stock displacement and headwork/cams that's cool too. (but I STILL REALLY like the thought of 88 cubes!!!)

So I guess my questions are these: (keeping in mind that cost is a factor - I don't want to spend the cost of a new crate twin-cam on my sportster!!!)

*What headwork is recommended for the 88" conversion? (I'd think that keeping the OEM heads stock may screw up the compression?) Also cam and carb recommendations?

-OR-

*Keeping the stock displacement, which stage headwork, cams, carb for the best result?

In short - go big inches or really fancy heads????

Hope these aren't too vague -
thanks!!!

As the old racing adage goes: "There's no substitute for cubic inches."

Especially where big low end torque numbers are the goal.

Turbocharge the sumbitch :)

Turbocharge the sumbitch :)

HAHA!

Now there's an idea!!!

They make turbo kits for the TC88s that standalone make more power than just about all of the kit motors running NA, plus you get a cool whistle and whoosh noises when you ride :) They don't like to do them on the sporties they claim because they become too wheelie happy :) For reference one of the companys turboed a fairly stock ZX11 sportbike and was laying down over 450hp to the REAR WHEEL, it had traction/wheelie issues anywhere south of 130 ish mph. people turbo hayabusas all the time, we are talking bikes that look bone stock..running stock rear tires and are trapping north of 160mph at the end of the quarter mile...talk about a rush.

If your talking low-end, I think your looking for cubes. The main purpose of headwork is to get the engine breathing better at high RPMs (more mix in, more exhaust out). More RPMs = more HP. Since your looking for low end, your looking to get those pistions hitting harder every revolution. Nothing does that like cubes.

Axtell 1450 kit for you, bro. NRHS can hook you up. Might be a good idea to get stage 1 headwork done while you can work it into some kind of package with them. As soon as my TC gets enough miles and needs a rebuild, I plan on giving them a call. But it won't be for a while.

If your talking low-end, I think your looking for cubes. The main purpose of headwork is to get the engine breathing better at high RPMs (more mix in, more exhaust out). More RPMs = more HP. Since your looking for low end, your looking to get those pistions hitting harder every revolution. Nothing does that like cubes.

Axtell 1450 kit for you, bro. NRHS can hook you up. Might be a good idea to get stage 1 headwork done while you can work it into some kind of package with them. As soon as my TC gets enough miles and needs a rebuild, I plan on giving them a call. But it won't be for a while.


I agree completely...I did the 95" kit in my TC with a Mikuni HSR 42 /SE breather and Hooker slip ons and left the rest stock to preserve my warranty and wow! what a torque monster! 90lbs.I would think an 88" Sporty would pull like a frieght train even with the rest of the internals left stock.
Y2K :smoke

This is what I like to hear ..a customer who ACTUALLY KNOWS what he wants

88" with a smallish cam like a 0.536 SE or maybe even smaller, but I don't think you'll gain a great deal more torque with a cam smaller than that on an 88".....see what Aaron or Justin reckon
I've done a few 95" Twin cams and they like a bit of cam to get the numbers out too...I've done a few with little 203 cams and they pull up about 98ft/lbs...a bit bigger cam and they free up a fair bit more torque as qell as top end

A good air cleaner

Stage 1 on ya heads

leave everything else alone...stock ignition, coil, leads, lifters, rockers, pushrods and jet the stock carb,

....reliable bulletproof 100+ ft lbs right where ya want it...and ya only spendin $$$ on the stuff that actually works

Thanks, Stevo!!!!

THAT'S EXACTLY the info I was looking for!!!!!

think the stock clutch is up to the job?

leave everything else alone...stock ignition, coil, leads, lifters, rockers, pushrods and jet the stock carb,

And those are things that people just LOVE to waste money on. But on 88" I'd probably want a little more carb.

think the stock clutch is up to the job?'

Yup. We ran a stock clutch on our 100" race bike and it held up quite well.

the stock carb is enuff for the rev range you're lookin at......it will restrict flow at higher RPM's tho BUT it'll be plenty for under 5500

I'm gonna have my cv on mine for initial running in and then I'll be stickin a bigger one on as, like Crim, I'm chasin bigger numbers up top

Ohh..did I mention I just took a new '05 GSXR1000 for a test ride...165+ at the rear wheel STOCK :yikes :D:D:D:D:D

And we scrape and scratch to get 100+ w/out splitting the cases. :(

yeah a 9 second bike off the showroom floor for 10% more than a 1200 buell


mmmmmmmmmmmmmmmmmmm......:D:D:D:D:D:D:D


My '03 is only down to low 10's :( with a quiet as a mouse stock exhaust ....cops can't hear ya doin wheelstands down the street :D:D:D:D:D:D

I was hoping to get a response from Aaron so everyone could see the info?

TN ... didn't mean to snub you, just busy lately and not much time to read the board.

Torque is really two things: cylinder pressure and the mechanical advantage it has.

Mechanical advantage on the crank comes from bore and stroke. Additional mechanical advantage comes from the gear reduction that lives between the crank and rear wheel. Gear shorter, you get more torque at the rear wheel, albeit with less rear wheel rpm. That's what gear reduction does, increases torque and decreases rpm by equal factors. Horsepower is torque times rpm, so it's not affected by making torque bigger and rpm smaller by equal factors.

But anyway, I think what you're really saying is not that you'd like more torque (that'd be easy, just leave the bike in first gear all the time), but that you'd like more power low in the rpm range, or in other words power made of relatively high engine torque and low engine rpm.

So one way to get that is to increase cylinder pressure at the rpm of interest. You can do that to a point with raising compression (to the extent you can control detonation), but there's a limit. You can also concentrate on cylinder fill at that rpm. You can optimize it there with port sizes, cam timing, and exhaust augmentation.

Ultimately, though, the most effective way is to give the burn more mechanical advantage on the crank, and that means more bore and/or stroke.

So my recommendation is to make the motor as big as you can, size the ports properly for the rpm of interest and motor size, time the cam events to match, and especially, use an exhaust system that augments the intake flow at that rpm.

The port sizes and cam timing can be calculated and modeled. Our CNC process actually does the port size caculation and generates a custom CNC program for the target size.

Best of luck.

Great info! Thanks!!!

Didn't mean to imply that I'd been snubbed, I realize you guys have important work to do!

I've learned a ton from reading your contributions on this forum.

I'll be calling you guys soon to work out some specifics.

I spoke to Justin on the phone the other day and as I understand it, the only difference in price between the 1250 and 88 is boring the case. I'm going to do the work myself (apart from machining) so it's a no brainer in my opinion. Probably going to cost an extra $150 to get the case done. Money well spent considering you get an extra 20 LBS of torque. Hp aside, you still get great torque from the 1250 but for me the 88 just seemed to good to pass up.
I'm going with the 88 kit, 04 heads, ignition and Bassani pro sreets. Cams and carb to follow.
What swayed me was the impressive torque. I don't, nor want, to ride at 5000rpm. I just prefer to chug around.

Let us know what you decide.

Cameron

yep DBT,

I'm a chugger, too.

I'm definitely going 88", probably on Sept. when some financial stuff is sorted out.