DIY Ebay Intercooler Piping Kit
 

I’ve gotten a couple of PMs from people with regard to my recent DIY intercooler system, with particular regard to cost and vendors. So I thought I’d do a full writeup on it so everyone can see.

Unless otherwise noted, all pieces were purchased off fleabay, and the prices shown include shipping, since that’s a big percentage of most of these type of sales.

First came the intercooler. $101 from a seller called autosquare. Avoid this guy like the plague. It was advertised as a bar & plate with 2.5” ends, but turned out to be a tube and fin with 70mm (2.75”) ends. I didn’t want to risk trying to get a refund from this scam artist, so I just cut the ends down and lived with it. Here’s a link to the auction so you can see what not to buy. http://tinyurl.com/oqy4o

To mount it, I fabricated a bracket that mounts to where the A/C condenser used to be. The vertical pieces are 3/4” x 3/16” flat steel, the horizontal pieces are 2” x 2” x 1/8” steel L-channel.

Next the aluminum pipe. This came from veccohighperformance, and totaled about $130. Three pieces of 2.5” 90°, one piece of 2.25” 90°, one piece of 2” 45° and three pieces of 2” 90°. I also bought the two silicone 90° elbows from him, total of $54 for those.

I bought two silicone reducers from seller622, a 2” to 2.25” and a 2.25” to 2.5” These totaled $40, and came with some surprizingly high-quality T-bolt clamps.

For the rest of the silicone couplers, rather than buy individual pieces I just ordered foot-long pieces of 2” and 2.5” from verociousmotorsports, totaling $36. The clamps I bought from a local speed shop (VW Paradise in San Marcos, CA) and they were about $30 in total. This stuff turned out to be very hard to cut. Unless you own a bandsaw, just buy the pre-cut pieces. If you order from seller622, he'll include free clamps.

I have an FM BOV which I wanted to mount remotely due to size and interference concerns. It has 1.375” OD fittings, which are tough to match. I wound up using couplers for 1.25” copper plumbing pipe from Home Depot, which have a 1.5” OD. I brazed a straight coupler to the side of the pipe which feeds the I.M., and used a pair of 45° fittings to make the turns. It’s all held together with a total of 12” of 1.5” silicone, purchased locally from VW Paradise as well. Figure about $50 for all that stuff. (copper has gotten expensive.) To do the brazing, I ordered a few sticks of muggy-weld, which is a low temperature alloy rod that will join most non-ferrous metals. It works, but it's very different from normal brazing. After this stuff melts, it's got the consistancy of water.

And that’s about it. All told, a total of nearly $500 for everything. The moral of the story? Unless you just absolutely have to be able to tell your friends with a straight face that you built the whole thing yourself, don’t waste your time. Just buy Stripes’ kit. :bigtu:

Pictures to follow…

Here's the bracket being fabricated. I cut the pieces roughly to length first, then clamped them in place on the car and tack-welded. I then moved to the bench for finish cutting and welding.

The intercooler mounted in its new home.

and I thought my one bent up aluminum bracket was over the top

Plumbing from the turbo outlet to the I/C inlet. Where the pipe passes between the P/S pump and the sway bar, I fabricated a little bracket which mounts to the lower radiator fan bolts and holds the pipe steady.

And finally, the I/C out to the throttle body.

Hehehe. Thanks.

I've managed so far to do this whole project in the one car garage of my apartment, which is in sort of a snooty upper-class neighborhood. Between the air compressor, the chop saw, the MIG welder, the drill press, the die grinder, the angle grinder, the band saw, the profanity, the constant engine revving, and seeing my hairy legs sticking out from under the car into the late hours of the night, it's a wonder the neighbors haven't had me tarred and feathered. :eek:

your car is freaking amazing so clean so DIY so good looking under the hood i wish i had your mad skillz

Thanks, Lunatic. Honestly, the only reason I do this stuff is to stay busy. I'm afraid of what will happen when this project is finished, I'll probably have to buy another vehicle to modify. :cool:

And now, a follow-up after one full week of driving.

First, my fears of the tube-type ebay intercooler seem to have been allayed. I have not yet touched the wastegate or added the MBC in, because I wanted to see what kind of pressure drop I was going to get. Before the I/C, I was usually seeing about 5.5 PSI according to my cheap mechanical boost gauge. Afterwards, I'm seeing around 5 to 5.25 PSI. Assuming this relationship remains linear, I expect less than 1 PSI of loss once I get up to 12 PSI. (actually, it may not even be that much, since going from 6 PSI to 12 PSI isn't a doubling of absolute airflow- more like 25%)

I haven't yet attached the thermocouples, but it seems to be cooling adequately. I've added back about 3 degrees of base advance back in, and still no pinging. (previously, I'd taken 3 degrees out, due to moderate pinging going uphill on boost).

Now, the bad news. That pipe which goes up and into the intake manifold has two fittings on it- BOV and idle air bypass. I thought I could get away with using Muggy-Weld (a low temp aluminum brazing alloy) to join copper fittings to the aluminum elbow. This has proved false. On the second day out, the fitting to the idle air hose popped off, so I re-brazed that, and then the very next day the big BOV fitting popped off. Needless to say, the engine didn't run well with a 1.25" hole in the plumbing. I had a rudimentary MAP-AFM substitution map for the EMU on the tablet PC as an emergency measure (I've been working towards AFM removal), and it worked, but the fuel pump kept shutting off as there was no airflow through the AFM at idle, and of course I wasn't carrying a paperclip at the time to jumper it on.

What's surprising is that in both cases, the brazing alloy stayed firmly attached to the copper, but pulled cleanly away from the aluminum. I've attached a close-up of the edge of the 1.25" hole where the BOV fitting was- you can see that the brazing allow just plain came unstuck from the pipe, leaving very little behind. I'd followed Muggy's directions concerning surface prep, heat and flux to a tee, but I guess there's just something about these pipes.

So anyway, I had to make a whole new piece out of steel, which has the advantage of being easily mig-welded. Bought a piece of mandrel-belt uncoated steel exhaust pipe from Summit Racing, 2.5" dia, 90 degree, 4" radius. Also a 3/4" heater hose nipple (for the idle hose) and a piece of 1.5" exhaust pipe for the BOV fitting. (I really want to know what kind of car uses 1.5" exhaust pipe...) I sprayed the finished product with plasti-kote aluminized/ceramic hi-temp exhaust paint, and it looks ok, but it's not nearly as shiny and cool as the aluminum was...

And, with the additional cost of the exhaust pipes, the fitting, and overnight shipping from Summit, I have now spent more on this debacle than Stripes is selling his kit for. :squint:

very nice.

I really wish all you guys were around 4~5 years ago when i started my greddy project on my old car.

Bracket????? I see a subframe!!!!!
I love it.

Joe, thanks for sharing the angles you used!

JB weld works really well for attaching the idle valve hose.

Very, very nice writeup, and the pics/explanation of the bends used is awesome!!!

so you would just say go buy stripes kit?

Buying a cheaper grade steel would save a considerable sum of money I would imagine.

BTW: Verocious is where I got all my exhaust tubing, great prices, fast shipping.

Thanks again, all.

The aluminum pipes weren't exactly cheap, but at about $130 for eight bends, I don't think they were outrageously expensive. That only comes to about $16 each, shipping included. If there was a shop in town where I could have custom bends done on steel I probably could have saved a few dollars (and eliminated a few couplers) but since I was stuck with using pre-formed standard pieces there's probably not a whole lot that would have been saved by going steel from what I've seen.

I considered JB-Weld, briefly. Two things turned me off of that. One, of course, is looks. I have a general aversion to using duct-tape or epoxy on my car. The only area of the car where I've applied JB-weld is on the threaded NPT to -8AN fitting on the oil pan, and even there I used so little that you can barely see it even if you know it's there.

The other concern was safety. I've used JB weld in other applications before, and it seems to become slightly brittle with age, heat, and petrochemicals. My fear was that should the fitting break (as mine did) that chunks of JB weld might tend to be drawn into the manifold, through the engine, and then exhausted out through the turbine wheel, possibly causing harm in the process. I realize the turbine is made of meatier stuff then the compressor, but I didn't want to take any chances.

So far the steel up-pipe has worked well. As you can see, I'm not the world's most talented welder, and all I have to work with is a cheap flux-core rig, but it does seem to be holding. I flogged it pretty hard on the way to work this morning and nothing fell off, which is more than I've been able to say thus far. Hopefully my luck will hold on the way home this evening. And tomorrow. And the next day... If everything holds together, I'm planning to install the MBC this weekend.

After welding the fittings onto the pipe, I sprayed it with a few layers of Dupli-Color 1606 high-heat ceramic-aluminum paint, and baked it in the oven for a couple hours. The result is not as bad as I'd feared. It doesn't match the other pipes, but it does have a decent-looking finish to it. I'd previously used this paint on the lower half of my Tony DP (the upper half I had professionally coated) and that piece has held up well.

Someone asked in PM how I cut the 1.5" piece to fit the 2.5" pipe precisely. Very simple, actually. I built a little wooden fixture to hold the 1.5" pipe steady (just a board with some 2x4s nailed to it) then I mounted that on the drill press and used a 2.5" hole saw to cut the 1.5" pipe in half right down the middle. I think HF sells a jig for doing this, but my way was cheaper. ;)

Firedog- I looked at Verocious for tubing, and while he's got some great prices on the straight stuff, his bends seem really expensive, and also have very short legs. The stuff I got from Vecco had long enough legs on it that I didn't have to use any straight pieces between them, it's all one bend directly to the next. Cut down on the number of couplers that would have been required in the longer sections, particularly the vertical sections.

I am doing an intercooler on my car right now, just taking a little break. As long as I can use all the pipes that I have and dont have to buy any extra then I should be at around 300 for my kit total. 130 for the IC shipped, and 170 for the pipes and sillicon. BTW....I ordered my IC from CXRacing, a very very good ebay company unlike autosquare. I got a 28x8x3.5in bar and plate IC for that cheap, and its REALLY nice actually.

Joe, please link everyone you bought from! :) Thanks!

I just bought my pipes. I finally got tired of doing research for something cheaper and just spent $94 for 4 pipes and 12 Tbolt clamps. In know that sounds crazy, but there's really nothing cheaper. I bought 1x70* and 3x45* 18"sections. I bought from CXRacing. The pipes were $14 each and the clamps were $22 w/$175 for shipping.

I think I'm going to buy my silicone from Reef Lights via eBay. They've got quality stuff and comparable prices. I need 1x45*, 3x90*s, 1x2-2.5"coupler, and a hump connector... plus a straight coupler just in case I need to splice in somewhere. It looks like that's going to run me 113.50 after shipping. That puts my total IC cost, including the mounting hardware at about $330 total.

I'm at work now... can somebody with a DSM T25 w/the 90* compressor outlet measure the damn thing and confirm the compressor outlet is 2".

"Roger.... Checking."

2" yes

You could upgrade your intercooler. ;)
Too bad it was all such PITA. Can't believe how poorly represented your IC was in the eBay. Congrats on overcoming the hurdles with a nice looking set up. Now's the fun part. :skid:

i saw this post and decided to do this myself because i hated my current intercooler mount, so i did it this weekend. Like he said it takes a while but it really does give you a satisfied feeling when you are done. I used 1" L brackets instead of 2" and then cut some pieces to make it to have a place to screw into. I am really pleased, so thanks for giving me the idea.

Very nice man. Congrats on the beautiful job. I decided to not go the intercooler route, yet.

Nice looking bracket, rharris. Looks like we have another member of the amateur MIG welding society among us. ;)

Glad I could provide a public service.

very nice intercooler bracket

I'm surprised you even purchased this looking at the ad I couldn't help but catch some spelling errors:

2: Messure of cooler
3: Alunium Bar Plate

I'm sure everyone at m.net would agree with you... but around here, there's nothing wrong with having english as you second language... I mean, we do drive Japanese cars right?:bigtu:

i have honestly never heard anything but positive stuff about e-bay intercoolers. Im even thinking of ditching my starion and doing a DIY just like u guys.

Your workmanship is outstanding. With the aftermarket getting so huge (blame f &f I guess) so much is such junk. I look at cars for sale online and I assume they are hack jobs because 99% are. What you have done reminds me more of a hot rodder. While I don't have a huge interest in v8 muscle cars anymore, I do respect the level of pride in their workmanship. I wish I had your skills and patience.

awesome work!

you have inspired me to do a FMIC setup to replace my crappy saab 900 set-up over the winter months.

my set-up looks like this:

http://www.**********/Saab%20IC%20kit.JPG

However it looks allot better from the engine bay view as you can see!!!:bigtu:

http://memimage.cardomain.net/member...67_54_full.jpg

would you care to comment exactly what I would need with regards to 90 degree bends, couplers etc and what size intercooler pls?

Rotaryjunky and Tabs, I appreciate the kind words.

You got me to thinking about the whole hot-rod scene as it stands today. For the most part, it seems that the images portrayed in the media are mostly about the “wheels-n-chrome” set, who mostly pay others loads of money to do their work . And what little attention is paid to the DIY crowd focuses on bolt-ons. You know: “I gained two and a half HP with this hi-performance air intake” and so forth. Thank God hydraulics and neon have fallen out of favor.

It actually makes me wonder if, outside of a few small sects such as our own, the shadetree hot-rodder still exists anymore. You know, the guy down the street who can fix damn near anything with an oxy-torch, a socket set, and a pile of parts that used to be a ’52 Merc.

I really hate hearing people bitch about how hard it is to work on cars nowadays, what with computer-controlled EFI and such. What, like jetting Weber carbs and futzing around with distributor weights was easy? I’ll take a wideband 02 sensor, MAP, and a dash-mounted tablet PC any day!

Where I work, there are two other guys who I’d classify as motorheads. One is a serious Mustang fanatic, the other has gone through an RX-7 and a ‘Vette and is currently flogging a very nice ’82 911SC. What bugs me though is that neither of these two are hands-on; Dave (the Porsche guy) doesn’t even change his own oil, and Jon (Mr. Mustang) paid someone to install a Vortech. C’mon, a Vortech install can’t be that hard! And these guys aren’t dumb- Dave is a CAD draftsman, and Jon is a serious electrical engineer who, among other things, designs ICs.

At any rate, I really appreciate the comments. Honestly, my car isn’t all that special (it's actually pretty ugly in places), I just enjoy tinkering.


Tabs, I guess you’ve noticed that this server filters out the domain name of the guy whose link you posted. That’s how much we don’t like Jim. ;) But to answer your question, I posted a pretty complete inventory of materials used (and vendors who I bought them from) in the first and ninth posts of this thread. But to summarize, I used the following:

3x 2” 90° aluminum bend
1x 2” 45° aluminum bend
1x 2.25” 90° aluminum bend
2x 2.5” 90° aluminum bend
1x 2.5” 90° steel bend (to weld idle and BOV fittings onto)
2x 2.5” 90° silicone elbow
1x 2”-2.25” silicone reducer
1x 2.25”-2.5” silicone reducer
4x 2” silicone coupler (cut from 12” length of 2” silicone hose)
3x 2.5” silicone coupler (cut from 12” length of 2.5” silicone hose)
1x steel heater nipple (for the idle hose, it was either .625” or .75”)
Misc fittings and pipe for BOV (varies by which BOV you use)
Whole lotta clamps

With the intercooler itself, you’ve got some freedom of choice size-wise. I’d recommend less than 27” overall length (end to end, not core length) and if you use one with something other than 2.5” ends you’ll just need to adjust the size of a few of the pipes and couplers. You should look for 2.5 to 3” thick for the core, height is whatever you think reasonable. Mine is about 6” tall.

And for the record, there’s a guy on this list called Stripes who sells a complete intercooler kit comparable to mine for about the same money as what I’ve spent on parts. His banner is at the top of this page – MX5projects.com

As an aside, here are some pics of the new pipe I made to go between the AFM and the compressor inlet. I didn’t want to drill out the stock aluminum piece since I still need it to pass smog. This is a piece of 2.5” steel exhaust tube, mandrel-bent 180° on a 3.75” radius (the tightest I could find). Summit part SUM-621008. I cut a wedge-shaped piece out of the middle to open up the angle a bit and then welded it back together- it maintains pretty much the same geometry as the stock piece. The air filter is a K&N RU-4950. It’s all rubber (no chrome) so it doesn’t chafe the underside of the hood.

thanks for replying!:bigtu:

There was some renewed interest in this in another thread, which led me back to this old post. I realized in retrospect that the tight shots of the piping that feed the I/C could be a bit confusing- some of them were taken from odd angles such as straight up from the ground.

I happened to have the nose off of the car today, so I snapped a couple of new shots that give a better overall perspective on the lower part of the tubing. Back when I first started studying this I remember having a hard time visualizing how the pipes should route around the radiator- others had done this before me, but I just couldn't quite see it. So hopefully these will make it a little clearer.

A wide shot. The pipes don't really extend as far down as they appear due to the perspective of this shot. They just barely go lower than the radiator:
http://img299.imageshack.us/img299/8818/wideqw4.jpg


Close-up of the left (US driver side):
http://img341.imageshack.us/img341/7...fttightty2.jpg


Close-up of right (US passenger) side, in which the water injection pump is visible as well:
http://img526.imageshack.us/img526/2...httightco8.jpg

Yours is the pretty version of mine
https://www.miataturbo.net/showthrea...410#post151410

Only 2 minor differences I saw:
1> I have a bend coming off the turbo, where you used a 90 and kept it high to maintain the AFM position. I don't have CARB here, so that wasn't an isssue for me
2> I went from 2.0" to 2.5" on the hotside directly, where you transitioned trhough 2.25" first.

Awesome post...thanks for the info and pictures.