K20 project off to a good start, volume 2

kmead

Glutton for punishment
Hussein’s approach effectively does what the two piece flap solution does, moving water from the window down to the bottom of the door. It is difficult to do it that way.

I made a similar solution to the factory approach that NEG shows. Mine goes on the outside of the door at the top to 2/3rds/3/4 of the way down where it then goes into the door ending an inch or so from the bottom of the door. A second sheet is then applied over the top of the first sheet where it goes into the door cavity and sealed to the outside of the door and the face of the first sheet. The first sheet is awkward at the front of the door due to the way the cut out is and the equipment behind there.

The plastic used is important but not super critical. I have a roll of 8mil UV stabilized black sheet. It is incredibly strong/tough and any thing intended to go through it needs a hole cut (an X for the through hole) I wouldn’t use this if I were you. Don’t use a trash bag as many of them have biodegradable materials in them and they will break down inside the door. A 4mil sheet should be good but 6mil makes for a somewhat more “structural” part which can be easier to work with.

Adhesives are a big deal. Honda uses 3M Snot ATG tape and it earns its name well, we use it on mockups all the time, it comes in a variety of thicknesses and is applied with a gun. Pass the snot gun never gets old.

I use weatherseal or ‘tyvek’ tape, it is often red and is used to seal tyvek to other materials on a house. I use this because the adhesive has a long life and it has good initial grab.

In the world of tape adhesives the breadth starts with masking tape and ‘duct tape’ on the one end which dries out and does nothing over time and 3M VHB tape at the other which is used to glue glass together or aluminum sheets to make ambulances…

Duct tape should be left to crafters, never bought for any other use and certainly never ever on a car.
 
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tvmaster

True Classic
No, the original is glued to the outside of the door frame. It is made up of two parts, the second is a flap glued to the main sheet half way down along part of its length. This flap goes inside the door frame and over the door release rod, wires etc. Difficult to describe. You can just make out the seam/weld line of the flap that goes inside in my picture below…

What year is yours again?
 

tvmaster

True Classic
Ok, same door design as a ‘74 then. Maybe the PO had already taken them off / on before, and lost the inner-flap if it even existed in the first place, as the small design changes this car went through are evident…
 
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I have not been inside an X door in several decades but I do remember mine having that flap. I assumed it was standard for 1974.
 

tvmaster

True Classic
I have not been inside an X door in several decades but I do remember mine having that flap. I assumed it was standard for 1974.
Ok, this is nutty - the flap is there, but someone had pulled it out and folded it under the main, outer membrane. I guess now it may make more sense how it’s supposed to insert into the bottom half. Every freakin’ day the garage unearths an exxe mystery…
 

Rodger

True Classic
Ok, this is nutty - the flap is there, but someone had pulled it out and folded it under the main, outer membrane. I guess now it may make more sense how it’s supposed to insert into the bottom half. Every freakin’ day the garage unearths an exxe mystery…
It’s the gift that keeps on giving.
 

lookforjoe

True Classic
With all of the talk recently by @lookforjoe regarding engine temperatures on his K swap, I have noticed that after a drive in mine, there is a lot of heat radiating off of the header. Hussein had fabricated a bracket and mounted the stock heat shield as I recall. In the process of fitting my engine at the body shop, the original header and heat shield were discarded. I decided to try this Lava Header Armor from Summit Racing. I found it a little challenging to work with as the outer dark fabric layer (Kevlar?) wants to separate from the thin underlying metal sheet that the insulation is bonded to once you cut it. Plus access to the header is a little tight, but I eventually got it on. It comes with some wire to fasten it, but I used these stainless locking ties instead as they seemed a lot classier and sturdier. They are like metal zip ties. After a good full temperature drive, I checked the heat off of the header and it was much less than without it. Yeah, it doesn't look as cool as the bare header, but I think the components near the header will appreciate it in the long run.View attachment 48307

Hey Rodger

Where did you locate your system O2 sensor? I don't see it downstream in the piping or cat. I've been told having it after the collector is too close for a properly merged exhaust flow from all 4 cylinders

Also, did you get HP/Tq numbers on your tune when they tuned it? Just curious what values you saw. The tuner also told me 5K onset range for VTEC is not optimal, but necessary when the intake/exhaust is hampered / flow restricted
 

Rodger

True Classic
Hey Rodger

Where did you locate your system O2 sensor? I don't see it downstream in the piping or cat. I've been told having it after the collector is too close for a properly merged exhaust flow from all 4 cylinders

Also, did you get HP/Tq numbers on your tune when they tuned it? Just curious what values you saw. The tuner also told me 5K onset range for VTEC is not optimal, but necessary when the intake/exhaust is hampered / flow restricted
Here is a photo that shows the O2 sensor. Aft of the collector by a few inches.
Exhaust 3 02.JPG


Here is my best dyno pull. 189.9 HP, 140 torque. My tuner felt that I could get more if I got rid of the catalytic converter.
Dyno chart K20.JPG
 

lookforjoe

True Classic
Thank you Rodger. Dyno graph looks good. Very similar curve to mine - nice even torque.

I'm guessing I should be seeing more than a 25ft/lb increase over the K20, , given the 2.4 vs. 2L displacement, and higher compression.
 

tvmaster

True Classic
Just as @lookforjoe said. I used sections of heavy duty large construction waste bags that I already had. Not as thick as the factory barrier, but works fine. I just did not want to invest in a large roll of moisture barrier that I would never use. I used the same Weldwood Landau Top Contact Adhesive that I used for my interior vinyl and carpet projects. Only thing is, the adhesive solvent wants to curl the edge of the barrier, so you have to handle it carefully when you start to apply it to the door. Start along the top edge below the window and then work around the edges.
Do you think the heavyness/weight of the replacement plastic barrier can also reduce sound levels? I have some clear plastic that would be fine, construction weight, six-mil polytarp, but not quite as heavy as the original. Worth the expense from a sound standpoint?
I also have this contact cement in the cupboard - this link is from a marine site which recommends it? Thoughts?


Any reason why a shower curtain liner wouldn’t be good moisture barrier material?

 
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tvmaster

True Classic
No, the original is glued to the outside of the door frame. It is made up of two parts, the second is a flap glued to the main sheet half way down along part of its length. This flap goes inside the door frame and over the door release rod, wires etc. Difficult to describe. You can just make out the seam/weld line of the flap that goes inside in my picture below…

“Over“ the door release rod? That doesn’t put it in contact with the window mechanisms in any way? It seemed to naturally want to fall underneath the handle rod when I was testing it the other day, or is either fine….
 

lookforjoe

True Classic
They had one that is about the same size as the SW muffler so I ordered that one. It is 14 x 9 x 4" with a 2 1/2" offset inlet/outlet. The SW muffler measures 14 x 8 x 4 so that makes the offsets a little different, so it will not be just a "plug and play" swap. The construction seems to be very high quality. They look to be mostly handmade as they are beautifully TIG welded and highly polished. The SW muffler is made from more stamped out pieces and seemed to be more mass produced. Still good quality, just different. Pricing is about the same for both. Here is a comparison of them side by side before I started chopping up the exhaust.

One thing I discovered after looking more closely at the insides, is the size of the internal pipes. When I was talking with the Solo rep, he said that the internal pipes on the Stealth are 2 1/4" but they can put 2 1/2" inlet/outlets on it. He didn't think it would make much of a difference. When I looked down the inside of the SW muffler, turns out it has only 2" internal pipes. I have no idea what difference that would make. I don't think it has any packing in it as it sounds like an empty paint can when you tap on it. The Stealth has a definite dull sound with tapping.

I got my STL25 a couple days ago - it came with 2.375" OD pipes, and is 2.25" ID. I called them, and they said they do have a 2.5" through-put with 2.5" OD piping version, but it would be louder than the STL25. At this point, I'm not going to send it back again, but it does seem their listing ID's are confusing to say the least. I assumed the '25' stood for "2.5", not "(2).25". Based on your description, it's the same muffler you bought, but yours they added 2.5 OD pipe ends...

post link
 
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Rodger

True Classic
I got my STL25 a couple days ago - it came with 2.375" OD pipes, and is 2.25" ID. I called them, and they said they do have a 2.5" through-put with 2.5" OD piping version, but it would be louder than the STL25. At this point, I'm not going to send it back again, but it does seem their listing ID's are confusing to say the least. I assumed the '25' stood for "2.5", not "(2).25". Based on your description, it's the same muffler you bought, but yours they added 2.5 OD pipe ends...

post link
When I ordered mine, the rep said that the intervals were 2.25”. I told him I was using 2.5” tubing for my system, he said they can put 2.5” ID inlet and outlet pipes on mine, so that is what I got. Turns out the SSW muffler I had before was only about 2” intervals after all.
 

Longitudinal

True Classic
The mating plates for the throttle body/intake that MWB provides in their kit have a threaded hole to install a pair of fittings. A hose is run between them to maintain the Idle Air Control Valve (IACV) function. I deleted the IACV and replaced it with a block off plate from Karcepts, as they say it is not really needed. I could have just plugged the hole in the manifold side, but thought I would use it for an emissions connection to the charcoal canister. I couldn't find a pre-made one that would fit the 1/2-20 thread of the plate, so I made this connector from a Stromberg carburetor fitting I got from Summit Racing. I cut off the 3/16 hose fitting and used JB weld to fit a 1/8 inch barb fitting to it. This is about the same size as the small connection on the charcoal canister. This fitting is on the bottom side of the so it is not really visible with the tube installed.

Please forgive the necroposting, but I want to make a correction in case somebody comes upon this thread looking for information:

The threads on the throttle body extension plates are 1/4" NPT, or at least they were when I designed them. The two flanges have the pipe threads tapped on opposite sides to allow the nipple fittings to face each other, then, as you said, a hose would connect them.

I am intrigued by your deleting the idle control unit. Those were always finnicky. After I chased idle problems on Whitstone's car down to gunk that had clogged up the control unit, I defaulted to opening and cleaning every single one afterward before the engine was installed. I also found it helpful for a smoother, more stabile idle to turn down the duty cycle of the idle control in Hondata. I wonder how well the engine idles without it, particularly with an intermittent load from AC.
 

Longitudinal

True Classic
I have to ask, why not just cut all of the wall off? Yes, you would have to move the fuel tank to the frunk, but is that so bad?

Pardon the second necropost on the same thread in one day...

There is a wisdom to FIAT's placement of the fuel tank. Toyota had a different but analogous solution on the MR2 (fuel tank in the tunnel.) The stock fuel tank is placed behind the car's second heaviest component--the driver--and very near center mass of the vehicle. Although throwing some weight into the frunk seems like a positive move in weight distribution, the reality is that there would be a notable difference in weight distribution between full tank and empty tank.

Also, as Rodger said, that frunk is handy.
 

Rodger

True Classic
Please forgive the necroposting, but I want to make a correction in case somebody comes upon this thread looking for information:

The threads on the throttle body extension plates are 1/4" NPT, or at least they were when I designed them. The two flanges have the pipe threads tapped on opposite sides to allow the nipple fittings to face each other, then, as you said, a hose would connect them.

I am intrigued by your deleting the idle control unit. Those were always finnicky. After I chased idle problems on Whitstone's car down to gunk that had clogged up the control unit, I defaulted to opening and cleaning every single one afterward before the engine was installed. I also found it helpful for a smoother, more stabile idle to turn down the duty cycle of the idle control in Hondata. I wonder how well the engine idles without it, particularly with an intermittent load from AC.
I am always open to comments and advice from those who know way more about cars, and especially this swap, than I do. You have probably done more of these than anyone out there. It is great to have you share your knowledge and experiences. I deleted the idle control unit based on something I happened to find on the Karcepts website. My experience is that when starting the engine cold, it runs pretty rough initially and I have to keep my foot on the gas pedal a little to keep the RPMs up, otherwise it stalls. After about 30 secs or so, the idle smooths out and settles in just fine. No issues with unstable idle after that. Without the IACV in place, you need to set the idle manually. I bumped it up to about 950 as any lower, there was an resonance issue that created a wicked vibration in the binnacle surrounding the gauges. Really annoying. Plus, when the AC compressor kicks in, it does drop the idle a bit, but not so much that it will stall.

My experiment with trying to hook the charcoal canister did not work out as I had hoped. There was too much air going through the canister into the intake manifold which raised the idle higher than I could adjust it down. So I disconnected it and capped the fitting for now.
 

Longitudinal

True Classic
I am always open to comments and advice from those who know way more about cars, and especially this swap, than I do. You have probably done more of these than anyone out there. It is great to have you share your knowledge and experiences. I deleted the idle control unit based on something I happened to find on the Karcepts website. My experience is that when starting the engine cold, it runs pretty rough initially and I have to keep my foot on the gas pedal a little to keep the RPMs up, otherwise it stalls. After about 30 secs or so, the idle smooths out and settles in just fine. No issues with unstable idle after that. Without the IACV in place, you need to set the idle manually. I bumped it up to about 950 as any lower, there was an resonance issue that created a wicked vibration in the binnacle surrounding the gauges. Really annoying. Plus, when the AC compressor kicks in, it does drop the idle a bit, but not so much that it will stall.

Aww, shucks... I enjoy this community quite a lot, and have some revelations coming later this summer.

Regarding idle adjustment, I have never liked tipping open the TB to accomplish that because the TPS always requires a subsequent adjustment. Have you considered using something (I can't say exactly what) as an adjustable orifice installed between the two 1/4" pipe threads on the throttle flanges? That way, you could adjust idle independently of throttle position.

Here's an adjustable orifice valve. I have no idea if it would operate in the range that you would need it to.


Come to think of it, you could install that valve in the cabin and adjust idle from the comfort of your driver's seat. :D

Regarding the charcoal canister, it sounds like you were connecting the canister to manifold vacuum, which would be way stronger than you would want. The canister would act as a big intake leak. The canister should plumb in upstream of the TB, and I think there was a small vacuum line to open the canister up under part throttle and allow trapped gases to be drawn into the intake stream. It's been a long time since I looked at one, so I could be misremembering part of that.
 
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