Single Carb. Conversion, VW Plenum & Modding, the OEM Manifolds

[westgl]

I started to jump ahead to what would now be Rev 3, but then stopped and made the current one Rev.#2

Rev.3
It uses the CX racing tubing, it is 6061T6 alum. tube, that has the 90 degree bend in it already, the lower mount to head plate would need to be made, then welded.

CX racing tubes are already polished, and are Mandrel bent, they are $13.00 ea., and would take the place of the all alum. tubing, and oem manifolds

This would also be a directed to port runner on all 4ea runners.

Rev.3 is all 6061 Alum. from Head mount to Plenum, then rubber hose attachment at plenum.

Rev.3 would transfer the most amount of heat to each runner.

Heated air into the intake, should help out a lot.

Heating the Intake air, should help with the Venturi cooling effect

How many people ride in below 40-degree weather?

 

[westgl]

Rev. 3, is the best of all.

I was trying to make the Cast alum Oem manifolds work.

The OEM manifolds will work, I will test ride to make sure.

But Rev.3 is the best method.

Rev. 3, will require you to make the triangular bottom plate mounts, for mount tube to the head.

That is why rev.#2 came about, it may be easier for some people to build.

Rev.#3 has the same concepts as Rev.#2, only a different way to achieve the goal, plus added runner heat, and tubes are already Bent, & polished.

 

[westgl]

I Dont think that there will be a Rev. 4, but i do have one more idea.

That can wait till later.

 

[Dave_J]

westgl » Tue Oct 01, 2013 11:36 am[/url]":25x0daxt]
How many people ride in below 40-degree weather?

Me, but on my Car Tire'ed Burgman. All the way down to 10F so far, even in the SNOW. But my CT is a Mud and Snow.

 

[westgl]

No fair, the Burgman with a Car Tire,

I have ridden my Burgman in rain and with the Car tire, it does really well, I have not ridden it w/ the CT in snow, rode some gravel roads, the CT tire is great on gravel roads, and some off road too.

Dave_J » Tue Oct 01, 2013 11:50 am[/url]":dqo7xrdz]

westgl » Tue Oct 01, 2013 11:36 am[/url]":dqo7xrdz]
How many people ride in below 40-degree weather?

Me, but on my Car Tire'ed Burgman. All the way down to 10F so far, even in the SNOW. But my CT is a Mud and Snow.

 

[westgl]

I came home from some errands at 3:00, changed my Throttle cable hold bracket to a much better bracket, very simple.

Temp out was 53 degrees, with off and on showers, road was wet, and i did not want to get caught out with a naked bike and no shield, in a down pour.

So i did not think i was going to get it out, for a ride.

I did start it, it seems to start a little harder than before, not quite that instant start, more like the OEM 4 carb Rack start up.

This was a VERY SHORT test ride, 10 minutes, not really enough for a good test ride, or a good test to see what it could do, and not good, do to wet roads.

Take off has changed some what, as the take off is more like stock OEM 4 carb rack, feels like some low end torque was traded for more top end power.

This is going from 1-1/4" ID to 1-3/8"ID.

Engine sounds even more lopey at idle now than it did.

 

[joedrum]

hmmmmm...this gose to show you things have to be just right ...hmmm

 

[westgl]

I am going to try some tuning of the tubing next.

I am going to test ride a few more times to verify, and go for a longer ride, on a dry day.

I really liked all that torque down low,

I had a kink in one tube and transitions were not as good as they could have been with the Rev.1, using 1-1/4" ID

So I wonder what Rev.2 would be like with 1-1/4" ID x 1-5/8"OD tube, as it would have better transitions than Rev.1 and no kink, or collapsing of hose as Rev.1 did, just a open, clear, round, path.

I may end up getting the torque back and maybe some added high end power, as i will have some added charge speed.

I would rather trade some top end for some low and mid range, to upper end.

I like a bike that can really pull your arm out straight out in front of you, while your body has that delayed reaction, of catching up, kind of like being pushed back hard into your seat by a high powered car.

Only with a bike it is the opposite, the bike wants to pull out from under you.

 

[dan filipi]

Would be curious as it sounds to me like 1-3/8" tube is too big.
Lopey idle isn't acceptable to me and tells me there's something underlying wrong since it ran better with smaller tube/hose.

I have an idea for a build but I won't post it until it's underway.

 

[westgl]

The charge speed through that 1-1/4" Hose on Rev.1 gave the bike a character, that i really liked.

I may get some 1-1/4" ID x 1-5/8" OD tube, funnel the ends at a 60 degree bevel, for a really good transition, and see what straight 1-1/4" ID tube does.

 

[westgl]

In Rev.1

I have 1.25" ID hose, with two reducers inside each hose that reduces down from 1-1/4" id down to 1.140" or slightly larger than 1-1/8"id x 5/8" long x 2ea.

Over a 4-1/4" long hose.

So I think 1-1/4" ID is going the right direction.

I think I have another idea to solve this problem and will tune the system even further.

I will start on it tomorrow.

 

[westgl]

This will be Rev. 2.2.

It will reduce the ID of tubing, but will also address a problem with the plenum.

The problem with the plenum may be a big fix?

 

[westgl]

Can someone measure the ID of one of the VW plenum outlets mine is in the bike, and all together.

 

[joedrum]

mine is too...im thinking 1 1/2 or a little less

 

[dan filipi]

Mine measures 1-5/16 I.D

 

[joedrum]

oops ID oh2:

 

[westgl]

Thanks Dan,

So 1-5/16" or 1.3125"

That is good, i measured it before but could remember, to many numbers floating around.

That ID measurement is at the outlet, close the the end of the outlet, That Outlet has been opened up, so that a type IV tube can slip inside it, and that reduces that 1.3125" down to

A smaller ID that matches the Plenum as it it deep into the outlet before it opens up.

So 1.3125" Plenum outlet, needs to be reduced down, to 1.125" ID or 1-1/8" that would complete the plenum size, and it would match my 1-1/4" ID Hose more closely with having the bands that are close to 1-1/8" ID.

I think that with the plenum going from 1-1/8" deep inside the plenum outlet (where the rough casting is measures 1-1/8" I believe) opening up to 1.3125" ID, then reducing, Back down to 1-3/8" ID is a whole lot of No way.

Here is what I will try next:
Reduce the plenum outlets the length of the outlet, from 1-5/16" ID to 1-1/8" ID, that would smooth out the plenum outlets, and provide a faster charge speed, through the Plenum and out the plenum.

If you reduce the volume, through the smaller tube (the larger volume may have slowed down the charge to much) and speed up the charge, we may get better drive ability back, & a easier starting bike, more low end torque, and shift the power from the upper range back to the Upper-mid, to mid, and Lower range, to provide a better riding bike.

then go to 1-1/4" ID tube

dan filipi » Tue Oct 01, 2013 5:26 pm[/url]":1djlfmay]
Mine measures 1-5/16 I.D

 

[westgl]

I cannot deny, that I was very impressed with my bike the way it was before.

But i have changed a lot, a 1/8" diameter for each tube is a lot.

Plus I had a reducer in each hose that reduced it down even further to 1-1/8' ID

So 1-3/8" ID reduced down to 1-1/8"ID that is a 1/4" diameter reduction. That is a lot!!! times 4 tubes

 

[canuckxxxx]

Mine measures 1.4" or slightly larger than 1 3/8".

 

[joedrum]

sounds good to me it basicly what I have but im closer to 1inch choke than 1 1/8 :builder: :mrgreen: