Ist off I purchased my 2006 FXDBI new in 2006 and have 7K miles. I have the V&H SSS exhaust with a Stage 1 download. I want to inprove the throttle response and have more torque. I am leaning towards the following, HQ-0039 cam,Compensator Kit,Performance clutch,Super Tuner,Cam plate support kit,lifters,Quick install pushrods and the required gaskets and springs, IPB. My riding style is 0-90 and cruise @70. I dont want to be the fastest but want the power when I want to pass the idiot in the cage. Some have told me to just do the Big bore and get it over with. What do you think ? I dont want to waste $ and like the look of my V&H SSS. I know I need a better intake but sat on a few with the SE intakes and they hit my knee. TY in advance.

 

First off, what's your budget?

The big bore alone won't do it. The powerplant is a system. Going from 88" to 95" by itself is not going to work. You need to look at a mild street P&P since the heads are coming off anyway. Then, head combustion chamber volume will dictate what piston to use (dome, flat top, etc) and what head gasket thickness to use to achieve about 10.0:1 static compression ratio. Then, you can pick a cam based on lift and the key parameter - intake valve closing to give you the corrected compression ration you are looking for. Most guys stick to 9.2:1 or less to run on pump gas, with a cranking compression of 190-195 psi. Play around with the big boyz calculator. Then, you are going to need all of the supporting bits and pieces - adjustable pushrods, lifters, camplate, inner primary bearings, etc. You may also be looking at high flow injectors than the stock 3.91 g/sec. You are also going to want to look at a tuner, like SERT or Thunder Max.
However, before you get too far into this - measure your crank run-out because you may be looking at serious bottom end $.

What is your target HP/Torque?

 

Jeff, I have the luxury of not being concerned about cost,that said I dont want to waste $. I have talked to the lead mech and the dyno tuner at a major Chicago area dealer and I am looking at the numbers and it just seems like maybe I should "go all in". I want to just get more throttle response and dependability along with a nice hp/tq curve. I am going with a tuner ( SE or ? ) but there are too many to choose. I thought cam,intake,tuner,have it dynoed and that would be enough. I just dont know and need help from others who have gone down this road.

 

If cost was an issue and you were considering doing this in phases, the starting place is displacement; best bang for the buck in terms of TQ/HP per $$ invested. I have to disagree the Jeff, have built a few 88" up to 95" with no other changes other than a .030" head gasket and there is a measurable difference in performance. You seem to be pretty thoughtful in your process so let's examine your situation in a very logical approach.

Increasing displacement from 88" to 95" will increase TQ/HP about 8%. So let's just say, for talking purposes, that your current Stage I configuration is making 80TQ/70HP. An 8% increase in displacement should result in an equal increase in TQ/HP, so going to 95" bumps you up to 86TQ/76HP for about $300, if you are turning the wrenches; that's about $50 a foot pound. Plus, you have the opportunity to mill the heads while they are off; no port work, just a boost in compression. This would cost about $75 and should be worth another 3-4 foot pounds of torque which brings the unit cost down to about $38 per foot pound. You have optimized what you have.

Look at another scenario, something along the lines of you current approach. You retain the 88" displacement and spend, what, $1000 on cams, pushrods, lifters and cam plate upgrade and, if you are lucky, you achieve the same increase in performance. Which is questionable because compression is still pretty anemic and not anywhere near what those cams need to be "happy"; you have not optimized what you have. So, let's say you get lucky and hit 90TQ/80HP as above. Great but you have now paid $100 per foot pound. So, if on a budget and approaching in phases, increasing displacement first appears to be the most cost effective solution.

I have left out the cost of labor, tuner/tune, compensator and clutch under the assumption that those costs would be common to either approach.

So, if cost is not an issue, you should definitley go "all in". You would be looking at about $1600 to bore/hone cylinders, new SE cast flat top pistons, cam plate upgrade, cams, inner cam bearings, lifters, pushrods, a "street port" job, gaskets and oil and an easy 100TQ/90HP. So, the unit price now is about $80 per foot pound. Again, keeping things simple and leaving out those costs that would be common to either of the above approaches.

I know the numbers may be off a bit; the above numbers are not based on buying parts "OTC" from a dealership. But the concept remains the same and I think you will get the point; go all in. JMHO.

 

Cam, intake, tuner and dyno would be good, but while you're at it you should at least consider having a street port on the heads and maybe having a HPI throttle body rework.

Then again, there is no substitute for displacement and while you're that far into it a mild big bore wouldn't be a whole lot more money, but would yield considerable performance.

I am just going through that now myself, and just today ended up taking mine to 107" for a relatively small increase in cost.

Good luck - you'll enjoy the boost either way!

Roger

 

Didn't you post this already. I remember answering on this last week. If your bike is an '06, then the HQ-0039 wont work. It's for 99-05 Dynas. It's also not the best cam for what you want to do. The HQ-0034 would work better. If you want to go to a big bore kit with a higher compression, then you open yourself up to better cams.There are a lot better than the 0039 though. If you leave it at 88" the Andrews TW48 will give you torque that will get you to 90 in no time. If you want a little more RPM, the TW37. If you go with bid bore and head work, The TW37 will still make great power or you could step up to the TW54 or TW55 if you go 10:1 or higher on compression. There are also some good choices from Bob Wood cams, S&S, or SE. I'm not a fan of single pattern cams, same lift and duration for both intake and exhaust, so I'm not crazy about the Wood cams. S&S would be my other choice outside of Andrews. The 2006 is a unique year. It has the better heads with beehive springs and the updated cam plate and tensioner. It is still an 88" though. You have to use the same cams for the 96" Dynas. The TW48 might give you an 88" that will break 90 lbs. ft at the rear wheels.

 

John, I did ask in the Dyna section and thought the Tech section would help out also. My mind is set that I will do the Big Bore Kit along with every upgrade needed. Port and Polish a definate. My problem started at the Dealer and I ended up questioning them. As you can tell with only 7K miles I am very limited in my free time. I only want to do this once and will go with what others have posted. The HQ cam is what the Dyno guy said to use and now I will do more research. I thought this would be an easy deal but too many options. THX again and if you guys want I will post the numbers and parts list when done. It is going to my Indy and then back to the Dyno. I wonder if buying a complete new motor might be the way to go. AHHHHHHHHHH.

 

One thing you need to know about the HQ performance stuff is that they like to sell a complete package; heads, cylinders/pistons and cams. The only way they will guarantee the number posted on their website is if you go with a package. The drop spin heads and do things their own way. Not saying they don't know what they are doing but sayin if you want to go withe HQ cams, go with an HQ package to get the full benefit. Otherwise, select a cam that matches your riding style and build around the cam.

IMHO, there is only one way to go if a complete engine swap is your plan; 120R is the best deal going.

 

DJ,I am not set on any brand,I thought simple cam,pushrod,tuner,intake,etc.would be a easy way to acheive the tq I am after. I am so confused now I dont know what to do, my bike is dependable,tuned and ok,I might just add a better intake and tuner. I also agree that matched parts ( SE, SS,HQ) are the way to go.

 

A sure fire program is bore to 95" to fit a set of SE cast flat top pistons, have Hillside or VeeTwin Performance (site sponsors) do a basic and low cost street port, Andrews 37 cams, set compression at 9.6-9.8 after consulting with the porter, SE Hybrid cam plate upgrade, tune and your done; 100+TQ/90+HP in spite of your exhaust and all for about $1700, plus labor if you aren't a DIY guy. No brainer, you are "all in" with a proven combination and you will love it it.

I helped a friend with the same build except no head porting, competition valve job, new guide seals, stock valves and springs, everything else per the above and that engine made 103TQ/96HP; that was a year ago and he is still as happy as a clam.