1907cc Microsquirt VFR800 ITB Build

[Slamd72btl]

So I'm considering making the switch to EFI with my new 1907cc that's in the process of being built. I'd have to do it cost-effectively as I won't have a huge budget for the conversion. I've got a few ideas - thought I'd see if anyone had any input about whether it's do-able or worthwhile. I should mention that it would be my first experience with EFI

Background:
Car is a '72 Super Beetle
70% highway/30% city driving
Daily driver
Driven throughout winter
Drive from Ohio to Chicago – 400mi, 6hr drive

Engine Specs:
New Rima magnesium case, full flowed, oil galleys drilled & tapped
DPR 78.4mm, Type 4 center main, Chevy/Buick rod journal
Eagle 5.325” Chevy Journal H-beams
Mahle 88mm A pistons w/ CB tool steel wrist pins
AA 88mm thickwalled cylinders, cryoed
Web 163 Cam on 108 LC
CB Super Stock 1.1:1 rockers
Tims 37.5x32 "Super" Stock heads (Valve seat area is hand blended to ports. Stainless Steel valves, 3 angle valve job) 88mm bore, HD single springs, cryoed
Dansk heavy duty stock size heater boxes
Dual Dellorto 40DRLA’s, CSP manifolds & bellcrank linkage
All factory tin, venturi ring, hoover bit
Dynamically balanced to 0.2 oz in

Power - Approx 105hp@5500rpm, 120ft/lbs @4000

FI & Ignition Ideas:
New FI Super Beetle Tank
Stock VFR800 fuel pump assembly mounted in bottom of surge tank, fed by feeder pump, mounted under gas tank
VFR800 TB’s w/ stock rails, injectors, & regulator - ultrasonically cleaned, injectors flow tested
VFR800 Stock injectors – 28lbs/hr, high impedance? Lower injector set only
Use CSP IDF/DRLA manifolds, CSP linkage, & K&N filters on TB’s if possible

LS2 truck coils (CNP) or Mario’s COP setup
Mario’s hidden crank trigger kit
Microsquirt w/ knock sensor, constant baro correction

Innovate MTX-L wideband
Dakota Digital CHT gauge
Possibly add CAN-EGT in the future

I'll add some diagrams and pics soon

[supaninja]

looks legit, can't wait to see the progression of this build.

[trbugman]

You'll probably have problems with fuel flow/pressure with the motorcycle fuel pump.
Motorcycle engines are a lot more efficient than cars.

[Slamd72btl]

There are a few places selling a direct replacement pump that supposedly flows 140-160 Liter Per Hour at 3.0Bar/13.5V, which according to a few of the online calculators I found seems to be enough for my low hp goals, (assuming the replacement flows the same as stock and their specs are truthful), but it's something I will look into more

[aircooledtechguy]

That's the same set of ITBs that I will be using on my Squareback when the engine is upgraded in the near future. I'm planning to just use the same Walbro pump that I currently have (and the same one that Mario sells).

I'm working on making some custom shortie manifolds so mine fit under the type3 engine cover.

Keep us posted on your progress. These could be a popular way to go since they are so close to IDF spacing.

[Vee Dub Nut]

What's the bore spacing of the VFR throttles?

[Slamd72btl]

Just purchased a set of '07 VFR800 ITBs off of ebay for under $75 shipped. That includes injectors, injector harness, TPS, fuel rails, and regulator. Should be here on Saturday and it'll probably be next week sometime before I can get to my dad's place where I can remove the Dells from the 1600 and see what the situation is with the fit and linkage, etc and what can be done. Fingers crossed

[Slamd72btl]

What's the bore spacing of the VFR throttles?

From what I've read they've got 36mm bores and a bore spacing of 92mm, just a 2mm difference between these and IDF's. See topics below for more info:
viewtopic.php?f=23&t=138616&hilit=vfr800
viewtopic.php?f=66&t=141463&hilit=vfr800

[Slamd72btl]

Bought a set of rubber flanges off of eBay today too for less than $35 shipped, making the project total less than $110 so far. The flange p/n was 07-100-15 , and they're discussed in one of the threads I linked to in my last post.

Provided everything goes well during mock-up, I'll send the injectors off for ultrasonic cleaning and flow testing and either soda blast or ultrasonically clean the TBs. I've read claims of the stock injectors flowing 294cc/min @ 43.5psi

I found another vfr800 build thread for VW that's the furthest I've seen anyone get with them so far: http://www.914world.com/bbs2/index.php?showtopic=192548

[Slamd72btl]

Some small progress. Received everything I ordered about a week or 2 ago and finally got around to separating the TBs


Vacuum line mess. Any way to determine what lines are necessary to reconnect?


The thing in the yellow circle is a valve which apparently has coolant flowing through it, and when the coolant is cold/hot/whatever, it moves the rod circled in black, which thereby opens/closes valves in the top of the TB (see next pic), which I believe helps the engine idle. Just based on what I've read..


Aforementioned valves/openings circled in blue


Shot of the linkage. It looks like the shafts are close to the same size as on the DRLA's, so CSP linkage looks promising


Flange info


Rubber adapter flange


Finally separated! The only issue I see right now is the outlets meant to connect the TB sets (circled in black) facing the wrong way. Maybe I can tap them and install 180* AN fittings and problem solved? Don't have the engine pulled yet to be able to mock up the TBs on the engine

Next up..
reattach the TPS
mocking up TBs on the engine
having injectors cleaned/flow tested
having TBs cleaned

[supaninja]

You're going to love those ITB's, last Sunday I got 33mpg on a 180 mile trip and I did 70-75 most of the way.

[Slamd72btl]

You're going to love those ITB's, last Sunday I got 33mpg on a 180 mile trip and I did 70-75 most of the way.

I'm excited to see what I can get out of it when it's finally ready

Today I marked where to make the cuts to separate the TPS to separate it from the metal piece that once held the TBs together. Just need to buy some more dremel cut-off wheels or come up with another method of cutting it. Sucks not having many tools

I used the dimensions of my current K&N's and it looks like they'll hit the fuel rails Good news is I think I have another idea. I think the velocity stacks from the Dells will fit - may need to slightly elongate the holes, but otherwise they'll fit. If I cut the tops off where they start to flare, I think I can do like the FI engine Jake has on his website and mount a set of 4 universal 'pod' type K&N filters. So I used the K&N site to do a search based on dimensions I think I have to work with. I came up with a killer deal, assuming it works. Fingers crossed $37 shipped for a set of 4 I have a few more prospects if this doesn't work out.



Inspiration photo

[Slamd72btl]

After taking a better look at things, it looks like I jumped the gun on ordering the air filters. They have an OD of 5.5", but even with the almost 1" offset at their flange opening, I think they'll probably hit the shroud, or at least look pretty out of place, given their size. Problem easily solved though - I think these will do the trick http://www.knfilters.com/search/product ... od=RC-0890, just cost more than the others at ~$20/ea. I also made a cool discovery today when I found these http://www.cbperformance.com/ProductDet ... tCode=7225, which I think will make the install of the filters a bolt-on affair I also opened up the VFR wiring loom and got the injector and TPS connectors separated, and ordered a new dremel cutoff wheel to finish the TPS separation. Hopefully I'll have something to show soon

[supaninja]

Half the fun of using the moto ITB's is having to be creative, I get a kick out of a good challenge.

[Piledriver]

Uni-Filter oiled foam pod filters are available in many sizes, flow well, and are great filters
(as opposed to any oiled gauze filter, which are only 100% effective at stopping gravel)

A lot of places sell them, aircooled.net sells a couple sizes, look for pod filters or stack filters.