Anyone fitted 40mm Mikuni flat slides?

[Flash]

I have 40mm Mikuni flat slides on my max. wondering if anyone else has fitted these and what jet size and stack length they used?

To be more specific the carbs are: TDMR40-D30

 

[lankeeyankee]

40's :surprise:
Just out of cuiosity how many miles can you get on a tank of fuel

 

[Flash]

40's :surprise:
Just out of cuiosity how many miles can you get on a tank of fuel

About 60 miles on the under seat tank, but fortunately I have 2 tanks!

 

[lankeeyankee]

About 60 miles on the under seat tank, but fortunately I have 2 tanks!

Damn I think you have the pooriest mileage thats about 15 mpg What displacement motor are you running to use 40's
I had 38 flatslides on a gsxr 1127 drag motor with head work and that was really on the large side

 

[Flash]

It's a standard VMax motor, and that's the recommended kit for it. But it does away with the need for VBoost. I have a vboost controller and have to set it to off otherwise the bike runs too rich.

The sound and throttle response is incredible though, but the bikes not as street friendly as it used to be.

 

[lankeeyankee]

It's a standard VMax motor, and that's the recommended kit for it. But it does away with the need for VBoost. I have a vboost controller and have to set it to off otherwise the bike runs too rich.

The sound and throttle response is incredible though, but the bikes not as street friendly as it used to be.

Have you dynoed it or race it with any numbers

 

[Flash]

Have you dynoed it or race it with any numbers

No. I have no idea how much power it is kicking out. The kit is supposed to increase power by 15BHP, so in theory that would be somewhere North of 150BHP.

 

[Flash]

Here's a good link I found for determining velocity stack length:

http://www.jrbranson.com/hondaracer/honda/intake_system_design.htm

Does anyone know the length on the inlet tract on a max?

 

[shawn kloker]

Davidon might have that set up.Can you post some pics?

I was running 41mm Keihin FCR's with 160 mains but just went back to my Stage 7 carbs with 160mk mains.

I have some R1 cv carbs that I want to eventually rack similar to the Keihins.It is really a bitch to get everything working and in there.

 

[Flash]

Davidon might have that set up.Can you post some pics?

I was running 41mm Keihin FCR's with 160 mains but just went back to my Stage 7 carbs with 160mk mains.

I have some R1 cv carbs that I want to eventually rack similar to the Keihins.It is really a bitch to get everything working and in there.

Here they are:

http://allensperformance.com/tdmr40-d30.html

I think the problem might be that I've got some foam filters attached which is screwing things up. I'm going to try and order up standard stacks and just run it without filtration.

 

[shawn kloker]

Those are the carbs that davidon is running.

Those are a very nice setup.Similar to what I want to do with these R1 cv carbs.

What's your jetting set up and what are the problems your are having?

 

[shawn kloker]

Those are the carbs that davidon is running.

Those are a very nice setup.Similar to what I want to do with these R1 cv carbs.

What's your jetting set up and what are the problems your are having?

Aren't those carbs $3000?

 

[davidon]

Yes i've got those. I think i switched to 165 (may even be 155 now)mains. I'm using Henny Raats filter adaptors and running K&N air filters. I have the Topham adaptors as well that I'm not using that i would sell if you want to go with no filter set up. My bike is at PCW now so i can't confirm carb sizes at the moment

 

[davidon]

Flash

By the way if you can be my parts contact for these it would be a big help (If I ever need them). These are not available in the US (some parts do interchange though) and Allen's was'nt that helpful

 

[Flash]

Flash

By the way if you can be my parts contact for these it would be a big help (If I ever need them). These are not available in the US (some parts do interchange though) and Allen's was'nt that helpful

Sure thing. Just PM me.

 

[Flash]

OK are you all sitting comfortably? Here is the scoop regards the velocity stacks.

Those Mikunis come with stacks that are 2.3" long.

When I purchased mine from Exactrep (www.exactrep.com) 'H' sent them up with 4 small lengths of braided hose, the same diameter as the stacks, and told me to cut the stacks in half (I went to a machinist who did it for a couple of beers), then insert each end into the hose to lengthen the stacks. the new length of each stack is 3.6"

So each stack now had it's original screw base, plugged into a short length of hose, then the trumpet plugged into the other end of the hose. To install these I had to screw the bases into the carbs, then squeeze the hoses over them with the trumpets already inserted into the hose. If you follow my drift...

'H' had discovered this magic stack length of 3.6" using his dyno.

Now applying the forumla posted in the link earlier:

Max revs on vmax = 9500
Power band kicks in = 6000
Mid point of power band = 7750

7750/1000 = 7.75

90/7.75 = 11.6" is optimum length of intake tract.

Length from inlet valve to top of carb where the air enters (you can measure this from outside by looking at where the head meets the barrel) = 8". This may vary for different types of carb.

Therefore each stack needs to be 11.6 - 8 = 3.6" long!!!

So 'H' and his dyno were bang on. How did H quickly arrive at the 3.6" figure??? Well my guess is that he tried the 2.3" stacks that came with the kit first and found the bike was down on power, then he measured the stacks inside the stock airbox, and surprise surprise they are also 3.6" long when you take account of the rubbers manifolds.

For filters he supplied these ITG foam boots. Each boot is an oval cuboid in shape with 2 holes in the base that allows it be pulled over 2 of the trumpets. The boots have reinforcing wire to maintain their shape.

The boots look a little like these:

http://www.patrickmotorsports.com/parts/IGE-FILTER-SET-39K.jpg

Only the undersides are also foam covered except for the 2 holes which slip tightly over the trumpet tops of the stacks.

Anyhow I am running 180 jets, and these seem to work better than 170 jets... but the vboost makes it go too rich. I'm going to try various jet sizes because apparently once they are correctly jetted they should be vboost compatible.

 

[Flash]

Yes i've got those. I think i switched to 165 (may even be 155 now)mains. I'm using Henny Raats filter adaptors and running K&N air filters. I have the Topham adaptors as well that I'm not using that i would sell if you want to go with no filter set up. My bike is at PCW now so i can't confirm carb sizes at the moment

OK I checked out my jets today and I am on 180 Mikuni mains. I tired 170 mains and that makes it run marginally worse. WIth the 180 mains the top end from 7500-redline works perfectly and is insane, but am the midrange is awful, and anything more than part throttle the whole thing bogs down.

So to summarise I can only use full throttle from about 7500 revs. Turning Vboost off makes things worse.

What revs can you use full throttle from with yours?

Are your jets Mikunis or Dynojets, cos the sizes work differently?

 

[113s&s]

problem is when carbs are to big ... velocity if down in turn it needs a richer mixture ... people mistake larger jetting for making more power...sounds like the richer jetting is just covering up or making the best of a bad situation and when gas milage is bad your down on power also

 

[davidon]

using MK jets..Did'nt have problems in midrange..only when going WOT did it hesitate and then take off. However i took off v-boost and also forgot to mention I'm running individual intake manifolds (not stock manifolds) as per PCW recommendation. You may want to adjust your needle clip setting. I think i did this. Only problem is it's a pain in the arse to get to and difficult to pull the needles out to adjust.
You may also want to pull out your pilot fuel jets and make sure they are clean (carb cleaner and air). These can clog up and screw things up..would do this first as these are easy to access

 

[Hercules]

A Boysen Quickshot[2] will smooth out some of the hesitation.