Bonneville America Forums Forums Technical Forums Performance Mods Ready to do the Mods... Looking for advice!

Ok... after 5 years and almost 40 thousand miles I'm ready to upgrade Elvira with some performance mods. Going to do it soon so I won't miss the summer riding. Here is what I'm thinking for the basic mods for Elvira's 790:

Big Bore Kit (904 Wiseco, D&D or TPUSA?)... 994 TPUSA???
Airbox kit (Freak, British Customs or TPUSA?)
CDI Upgrade (maybe the mild one... just some additional R's before hitting the limiter)
Heavy Duty Clutch and Springs

Options??? Head Work? Billet Manifolds?? Anything else???

How much $ are you planning on spending?

Depending on your budget, definitely head work and carbs. Really though, we're stabbing in the dark unless we know how much you're willing to spend. From what I've been told, anything bigger than a 904 and you're talking major cash and work outlays, so more info required if you want anyone to suggest any serious ideas.

Just wondering why you mentioned 994 though?

cheapest mod is the ghetto freak, drill the airbox and save big bucks over a kit.
Big bore is a huge improvement and will make it a new bike.
Any of the 904 kits work well.

Budget is going to be $2500 - $3000. As I am a mechanical idiot this will include labor.

994... essentially a cylinder swap like the 904 (except it requires some case work) and it makes the overall engine look bigger. Probably WAY out of the price range since I have no idea what the case work involves. OR, this would be the only mod without money to do any others.

do the 904 you will be surprised what a change it will give you.........find a dyno and tune it properly

I reckon you almost answered your questions yourself if you have $2.5k - $3.0k play money.

Quote:

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• Big Bore Kit ... • Airbox kit ....• CDI Upgrade and
• Heavy Duty Clutch and Springs.

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Depending whether you can do some of the less technical yourself though, there may be enough $$$ to do some more but like you I'm still learning so I'm not going to try to pretend I know more than I do.

What I would suggest simply as a start is to take the "advice" (sorry, that word's only for dumbies isn't Pat ) idea of contacting Matt at TPUSA.

Dealing with this stuff all the time and advertising his prices up front, says to me he's competitive and isn't trying to squeeze a few lazy bucks out of the unsuspecting.

I've also been in contact with him several times so he's not hard to get hold of either. Why not tell him your budget so he can suggest the best priorities?

Find someone local and see how much he'll charge to do the BB first, then you know how much you can buy. Get the BB kit and as much head work you can afford (I would go with Triumph Performance USA).You can do the Freak and add carbs yourself or add them later without to much down time.

Good suggestion... I'll call around to some machine shops to see what the cost is for the wiseco mod and go from there. This ones seems to be the most ecomomical of the 3 major providers (Brent, D&D and TPUSA). I'm leaning toward just the 904, CDI and HD Clutch. I looked at the airbox and think I can handle drilling it out (which would reduce the outlay by around 400 (kit plus labor to install). That might leave some room for some minor headwork.

Just drilling out the airbox ? Do you mean opening up the bottom? I did that for my 08 America and dropped in a K & N filter and it made a difference, however, with additional mods I think you would want to eliminate the air box and go with pod filters for a much better improvement. I did my own air box elimination, and I am not a mechanic. It was a straight forward job and adding pod filters makes a difference.

Since you've been happy with your bike for 5 years you probably don't need to go too extreme to add additional power. Removing the air box and adding pods, going with billet intakes, change to a stage 2 igniter and drop in a set of 813 cams, all for probably around $1,000 and you'll have 10 - 15 hp more than stock.