restoring & adding a modern touch to a 86 vf500

buzz kill... but you are the authority figure when it comes to the 1st and 2nd gens...

lets see how close he gets.

 

I am a big fan of the VF500F.

This said my research into custom valve kits, hard-faced cams and rockers - parts only - is easily in the $1500 range for the top end. The VF500F is known for its neutral handling and as anyone who has owned one will state - it is one of their favorite bikes for taking on country roads.

As noted, suspension and wheel upgrades are a great choices for the VF500F.

While I admire Matt's dedication to tweaking his bike - 32mm carburetors, high performance coils, radiator redesign,,, having a goal of 80 HP doesn't seem realistic for this engine.

Creating a top end ‘kit’ – which would help to remove some of the wear issues associated with the engine and perhaps give a slight HP increase - does seem like it can be accomplished. Perhaps this could be a group buy – to help keep the parts costs down – but it would still be a serious investment for those interested.

 

^^ Well put.


I'm glad Jamie and IC jumped in with their 2 cents.....I didn't want to be the negative nancy saying that 80whp was an overly optimistic goal.


Handling and reliability mods would be the best bet.

 

Thank you for the post.

Do I have the Accel specification correct - you are using 3 Ohm inductive coils paired with 8.8 stainless/silver-plated plug wires and non-resistor caps?

 

very well put everyone 80 is a high number to shoot for but this bike will have 80 WHEEL horse power

 

yes except mine are non cdi

 

So that means you'll have even more at the crank.

On that topic....what do you guys think the HP difference is between the Crank and at the rear wheel?

10%?

 

Apologies if I'm being daft here but I want to double check - on Accel's web site there are two choices (from what I've noted) 3 Ohm Inductive p/n 140403(k) - or - .7 Ohm CDI p/n 140404(k).

You are using the 3 Ohm Inductive p/n 140403 - correct?

 

I wish I knew what you were talking about

 

As far as I can tell the engine on my 599 is rated at 95 or 100 HP. Dyno tests I've seen between 80-86. So 10% would be the bear minimum loss-wise. This is also on a bike that's 20 years newer.

 

Well considering when Matt dyno'd the bike when he first got it, it made 29.9hp & 15.8ft lbs@10,000rpm which equals to about 35hp & 17.5ft lbs at the crank (That's adding 15%....not 10%)

Matt's main power gain focus is to bring it back up to stock spec.


Matt....you gotta almost double your power output from the day you got it dyno'd. I think that'll be a piece of cake for ya.

 

Okay, I'm adding a disclaimer here - I am in no way an electrical engineer - this said, the VF500F uses a capacitor discharge ignition (or CDI) system and not an induction system. Matt's coil choice - if I am understanding correctly - is a 3 Ohm inductive coil.

I've read that you shouldn't use inductive coils on a CDI system but Accel may be suggesting this as it is a closer match (in terms of primary resistance) to the stock VF500F coil which has a primary resistance of 2.8 Ohms (for reference Accel's CDI coil is .7 Ohms).

I have an email out to Dyna and Accel regarding their thoughts about using an inductive coil with a CDI system (Dyna is also recommending a 3 Ohm coil p/n DC1-1 w/ DW-200 copper core plug wires) regarding this. I'll post what the tech's have to say when I hear back.

 

Keep in mind that Matt's bike wasn't running right when he got it. Anything over 55hp at the wheel for a VF500 is doing really good. 80hp at the wheel is about 95hp at the crank. Not really practical - that's a 190hp VF1000 for comparison.

If you could boost the rev limit you might be able to help your cause. More rpm = more hp providing you can supply it with fuel...... and keep the bottom end together. Tack on some zeros for a custom, one-off Falicon crank and Carrillo rods!

 

140403 is the correct part number to use with the early VF's. Even though the ignition systems are indeed CDI type, the coils and coil drivers are still old-school. That's because those bikes were made in the transition from old technology to newer tech. If you try using the CDI Accel coils you would get flames shooting out of your spark box(es). Not good!

 

Thank you for the post.

I also heard back from the tech at Dyna - "The difference between the 2.8 and 3.0 ohm in the coils is nothing to be concerned with performance or spark wise. Conversely, if you went to a 2.2 ohm replacement coil instead of the factory specified 2.8 ohm coil it would either destroy the coil and/or the ignition module in a short time."

Looks like 3 Ohm coils (if selecting either Dyna or Accel) are the way to go.

 

Just an FYI - I have heard bad things about Dyna's quality. I've seen some guys on the V4HondaBBS who aren't happy with them.

 

It's difficult to build an SV650 that makes 95rwhp and still maintain reliabiltiy. I'm with the other guys in saying that there's not much point in trying to get 80 out of the Babyceptor. If you do get there then it will only be for a short amount of time, i.e. when the NOS bottle pressure gets low!

It's much cheaper and easier to buy a fast bike than to make a slow bike fast.

 

yeah but wheres the fun in that? lol

 

Thank you for the FYI.

While I personally have had good experience with Dyna's coils (on a CB400F project bike I completed a few years back) I did have a heck of a time with their suppressive core wire - which is what Dyna had recommended at the time.

I believe they have since changed their specification to copper core (non-suppressive) wire. Accel also recommends a non-suppressive (in their case stainless steel/silver-plated) wire.

One of the benefits I see to the Accel kit (over the Dyna) are the connections at the sparkplugs - as Matt has noted in an earlier post – as Dyna recommends re-using the plug caps.

This said it is good to note that some other VF owners have had reliability issues with Dyna. While I did not experience this I appreciate the intel.

On side note, I wrote to Accel to ask them about their plug caps - specifically if they have resistors. I'll post their response when I hear back.

 

Agreed, I think it would very sweet to have that kind of power out of a VF500F. You never know maybe Matt will actually do it and make us all look dumb.