From: "G. D. Aucott"
To: toyota-mods@cyberspace.cyberauto.com
Date: Fri, 08 Mar 1996 15:41:25 EST
Subject: MK1 Intake Mod
I've received several requests for info on removing *all* the intake plumbing
on the MK1, so here goes (this gets long)...
The MK1s have a rubber pipe that goes from the MAF to TVIS. On the 85/86 this
pipe is about 8-10 inches long and has a slight bend, on '87/88 the pipe is
longer and has two severe (90 degree) bends. This pipe can be replaced with
a single, straight rubber pipe about 6" long for around $5. Procedure:
85/86: Remove *all* the intake plumbing including the airbox, rubber hose,
MAF, filter, resonance box, etc. This will require you to remove a couple
bolts and brackets, disconnect the MAF, and (if you have air conditioning)
disconnect the vacuum line for the idle-up circuit (?). You will now have a
BIG hole where the airbox used to be.
Measure the inside diameter of the rubber pipe or the outside diameter of the
TVIS side of the pipe. If I remember right it's about 2.5 inches (65mm or so).
Go to your local hardware store -- I've seen the rubber pipes at Builder's
Square, Home Depot, and the local stores, so they're common. In the pipe
section you'll find several diameters of a rubber pipe with wall thickness
of about 1/4 inch (7mm) and about 5-6 inches long. Choose the one closest to
the diameter you measured... don't rely on the writing on the package, for
some reason a 2" pipe is really something like 2 3/8. It should be under $10.
The MAF diameter is about 1/4 inch larger than the TVIS side, so once you have
the pipe you'll have to MASSAGE (stretch) the pipe onto the MAF. This is
difficult because the rubber is stiff, but it works (stretch it with your
hands first, then work it onto the MAF in a circular manner). Clamp it in
place and go back to the car. The other end of the pipe will slide right onto
the TVIS.
Next you'll have to make some brackets to support the MAF because you've
moved it closer to the opening in the hood (higher in the engine compartment).
Simple brackets will work, and there are plenty of places to bolt them down
inside the engine compartment (thanks, Toyota).
If you have an '85/86, you'll need the adaptor to go on the end of the MAF.
This is a small cast aluminum plate that bolts to the MAF where the airbox
was and provides a round flange to mount your filter on. This can be bought
from Select Sales or Options (Chris, do you have this?). The '87/88 already
have this built into the MAF so you won't need it.
I installed the Select Sales cone filter, which *just* fits inside the shock
tower. This is a nice cone filter, but I suppose you could use K&N or any
other filter of 6 inches or less.
If you don't have air conditioning, THAT'S IT! You're done. It took me
about 1 hour. If you have air conditioning, you need to figure a way to
reattach the vacuum line. I haven't reattached mine yet (just unplugged the
connector that turns on the vacuum), but I'll be either installing a fitting
into the MAF flange (drill, tap, screw in place) or using the fitting from
the old rubber pipe, drilling an undersized hole in the side of the new
rubber pipe, and inserting the fitting there with an interference fit. I
don't know if this will work yet though. The fitting WILL work.
I think that's enough for now. If there are additional questions feel free
to ask. Chris Berchin removed all the plumbing from his '88 (significantly
different) so I'll ask him to post on removing that.
..............
Dave Aucott
1986 MR2
daucott@e-mail.com
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Date: Thu, 7 Aug 97 06:02:29 UT
From: "Todd Anderbery"
Subject: MR2 Intake Mods
I recently was checking out some other MR2 related web-pages and came across a
guy who had an 1988 MR2 with certain mods including a custom air intake
system. I studied the way it was made and then took a long look at the stock
system and came up with a way to improve, drastically, the performance of an
MK1 using $15 in parts and reusing all stock componets. Heres how I did it.
The Car: 1987 Toyota MR2 Normally aspirated.
Re-use these parts:
1. MAF system (needed by computer)
2. The intake plumbing.
1. 90 degree tube from TVIS and MAF to Air box tube about a 30 degree
tube also connected to plenium box.
Parts needed:
1. Air valve from a car or bicycle tube with pressure regulator removed (the
little needle inside the stem)
2. A 4" air filter and case by Fel-Pro. $12.99 at Pep-Boys.
3. A thin sheet of rubber about 4"x4" and a 1 3/4" hose clamp.
Instructions:
1. Remove the MAF system and tubes.
2. Identify the tubes you will need to re-use, only 3 in the system.
3. Poke a small hole in the center of the rubber sheet (or a cut bike tube)
and place the valve stem into it and titghten nut to secure a firm fit.
4. Take your 30 degree tube and cover the plenium hole with the rubber sheet
making sure it is pulled tight and the stem is near center (a little tough
with one person) and clamp it into position using the hose clamp.
5. Attach the same tube to the TVIS (or intake) with the stem side toward the
cabin. Also attach the hoses that were previously connected in this area, also
connected to the MAF to the stem.
6. Clamp the MAF to the end of the tube. You may need to pull the wiring
harness up a little to gain slack from the wires.
7. By now it should look like the MAF is leaning down at an angle. Make sure
the MAF is positioned correctly, large wiring harness towards the trunk(rear).
8. Clamp the filter can onto the small opening of the 90 degree tube and seal
the small hose opening with a bolt or a BIC pen will do temporary.
9. Clamp the tube and filter to the MAF and check your hoses for tightness.
10. Start the car and check for leaks.
I have noticed a dramatic increase in power throughout the entire RPM range
and she now seems to pull all the way up to redline. Profesional systems can
cost into the $200 range for the same thing and this seems more feesable for
the rest of us who want more power but can't see spending that much money
without testing it first. You can also make your own from scratch with
plumbing parts from the local hardware store. I'll send pictures once I know
were to send them.
P.S. the chrome air can looks good under the hood also.
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