Throttle Body Overbore Teaser

[CandyRedRC46]

I just received a spare set of throttle bodies in the mail today. I am going to send them to maxbore.com Monday to be overbored, have the throttle shafts thinned and then filled with larger butterflies. I will be then port matching the boots to the throttle bodies and intake ports on the heads to the boots. Here's what we are starting with, I'll post up the new dimensions in a week or two when I get them back. I'm hopping for at least 42mm (as the entrances are already 40mm) but really anything over 36mm will be an improvement. (As the exits are only 32mm x 35mm)

[Switchblade]

Candy are you also going to R6 velocity stack on the VFR ? I alway thought the 6th gen un-equal ones are FU.

When I get the rapid bike racing I will tune each cylinder individually, so I will be ditching the staggered velocity stack arrangement. I will probably need some bigger stacks after the overbore. As I do not know how much the throttle bodies can be overbored yet, I do not know which velocity stacks I will be going with yet.

Got it and good point .

[CandyRedRC46]

Throttle bodies shipped out this morning. I should have the results of how far we can bore our throttle bodies with in a week or two.

[Switchblade]

Wow he is fast .

[CandyRedRC46]

Lol I mean I shipped them out. He should have them Wednesday and he should let me know what can be done by Friday. I think I'll have them back some time next week.

[CandyRedRC46]

Update, just got word back. Apparently our throttle bodies are just 35mm's. Maxbore will be taking them to 38mm, fitting larger butterflies, thinning out the shafts, fitting low profile screws and port matching the boots.

So what we will wind up with is throttle bodies that should flow like at least 40mm throttle bodies, but still maintain the lower rpm velocity of 38mm throttle bodies.

Also as a side note, I will be sending off the injectors to be cleaned and I will be port matching the intake ports on the heads, to the throttle boots.

[CandyRedRC46]

I just received my throttle bodies back from maxbore.com. I will try to get them in shortly and report back to you guys. Here's some pics of the 2mm overbore.

[CandyRedRC46]

I'm kinda dissapointed here. While the throttle bodies were overbored, it wasn't by very much, as from the factory, the inlets are already 40mm so the overbore didn't even begin until about halfway in between the inlet and the butterfly. No tapering was performed at all and they were only bored to 38mm. They did match the boots though, but it appears as though the throttle shafts were not thinned or even touched at all. Also it doesn't appear that low profile screws were used either. I'm not too happy about this. I will be sending out an email in the morning.

[Switchblade]

Yeah don't blame you . At least you have a cooler of beer ready.

[Switchblade]

It looks like he never disassemble the throttle bodies. Right ?

[CandyRedRC46]

Well I got a hold of him. He assured me that all work was done. I'll be looking at them very closely, side by side when I do the swap....

[Rush2112]

Well I got a hold of him. He assured me that all work was done. I'll be looking at them very closely, side by side when I do the swap....

He charged you $70 for those 8 throttle plate screws!?!

They look like regular phillips head machine screws...

[CandyRedRC46]

The $70 was for thinning both throttle shafts, $35 per shaft and the low profile screws. It really doesn't look like anything was done there. I will look at them side by side shortly to confirm if there is any difference. I am toying with the idea of pulling the butterflies off myself and carefully knife edging the throttle shafts by hand. But, George warned me that our throttle shafts are brass and will easily crack if too much material is removed.

[Veefer800Canuck]

I would gladly lose 0.1% of airflow if it meant not sucking bits of throttle shaft and butterfly screws through my intake valves.

But I've been called chicken before, so........

[Switchblade]

Still not on the bike . Right?

[CandyRedRC46]

nope not yet. youll be the first to know ;)

[CandyRedRC46]

Just finished having the injectors cleaned and flow tested. They were off big time. I am happy I had them cleaned before I just slapped the over bore throttle bodies on there.

Vfr800 injectors 1: http://youtu.be/ZoIK_BSAEzo

Honda VFR800 injectors 2: http://youtu.be/APnhuEmjnFw

So..... Who wants my old throttle bodies? Lol

They are port matched to larger R6 velocity stacks and have a light upper and lower port and polish to remove all casting marks above and below the butterflies.

[Switchblade]

Just finished having the injectors cleaned and flow tested. They were off big time. I am happy I had them cleaned before I just slapped the over bore throttle bodies on there.

Vfr800 injectors 1: http://youtu.be/ZoIK_BSAEzo

Honda VFR800 injectors 2: http://youtu.be/APnhuEmjnFw

So..... Who wants my old throttle bodies? Lol

They are port matched to larger R6 velocity stacks and have a light upper and lower port and polish to remove all casting marks above and below the butterflies.

With or without injectors ?

[CandyRedRC46]

With injectors.

[CandyRedRC46]

The throttle bodies that I will be selling are the ones that are on my bike right now. I have not installed the overbore throttle bodies yet. The injectors that I just had cleaned, came with the throttle bodies that I had overbored and will be going back into them when I do the install.

[Ranger77]

Candy, is that you doing the injector cleaning or where you there just watching? If first, do you clean others injecors? If second, hiw much was it to clean 4 injectors?

I have a few sets of injectors that Id like to see how they flow.

[The Phantom]

Suggestion, don't sell the old tb's until the new tb's are in and running happily :)

[CandyRedRC46]

Candy, is that you doing the injector cleaning or where you there just watching? If first, do you clean others injecors? If second, hiw much was it to clean 4 injectors?

I have a few sets of injectors that Id like to see how they flow.

Just watching. It was $15 per injector. That's usually the going rate. I got lucky and they misquoted me $45 total though lol

Suggestion, don't sell the old tb's until the new tb's are in and running happily :)

Well yeah, I won't be able to list them or ship them out until the original ones are out of the bike.

I'm installing the o2 sensors in my exhaust today so the bike will start real time tuning. Then I can swap in the throttlebodies and let it tune for the increased airflow. Plus I'll be able to look at the fuel tables and see how much more air its bringing in.

[CandyRedRC46]

So over the last 24 hours I fitted the overbore throttle bodies and boots and port matched the heads to them. Here are my updated maps. It is up about 20% more fuel everywhere over my last map that had been made the day before. I would ignore the 0% column. I need to sync the new throttle bodies pretty bad so the 0-4% fueling is off.

[Rush2112]

Wow!

Big difference... how does it ride and feel?

Have you done any quarters?

[CandyRedRC46]

Haha I literally finished installing everything at 1:30 this afternoon. I'm going to let the tuning sort out for a while first.

Hopefully I'll be able to do some dyno pulls and 1/4s soon. There is talk of there being a cycle pro rapid bike drag night soon :)