Turbos - Intercoolers Tuesday, 02-Jan-01 12:44:30 207.191.66.157 writes: Just read the article in Hot VW's concerning blow through 44 IDF's. Sounds interesting. I have a question about the necessity of an intercooler. Is this an issue with this design of a turbo-charged engine? Jim Brown

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Re: Turbos - Intercoolers (Steve Arndt) (02-Jan-01 12:51:57)

Re: Steve, Happy New Year. What kind of compression are you going to run? (n/t) (Ron) (02-Jan-01 13:05:07)

I have two cams in mind. A Raby special cam which is kind of mild at at 7.8:1. The other option is 8.3:1 and an 86B/86C. I'm leaning towards the B/C because I'm going to run light valve train good for 7500 RPMs. (n/t) (Steve Arndt) (02-Jan-01 13:09:35)

Steve - Can you recommend some good reading on turbos for our aircooled VW's (theory ok too). I don't know much about in general and would like to learn. Heard that Turbomania is good, but haven't been able to find it. Everybody tells me it is out of print. Thanks (n/t) (Adam from Atlanta) (02-Jan-01 13:06:17)

Turbo Chargers by Hugh Macmanis (sp) is OK. Find Turbomania. 21st Century performance from www.autospeed.com is truly awesome!!! I just got this book last week and I love it. 280 pages of killer Motec, Haltech, intercooler, suspension setup, wing design, etc. info. $45 for a book is steep, but learning isn't cheap. Also www.sdsefi.com has great tech articles. Talk to people that know, and listen. I have no experience myself, I simply relay information :) (n/t) (Steve Arndt) (02-Jan-01 13:12:16)

Re: ) Steve...I have had several turbo projects. What is the specific name of the book at AUTOSPEED that you are referring to. I would like to order one. I went to the site but could not find the book reference. (n/t) (Rick M) (02-Jan-01 13:19:25)

21st Century Performance is the title. Go to their site, then to the Online Store section. (More, click message) (Steve Arndt) (02-Jan-01 13:23:02)

I bet this book is good too. I'm going to order it shortly. http://www.autospeed.com/cgi-bin/browse.cgi?category=410&product=18& (n/t) (Steve Arndt) (02-Jan-01 13:30:39)

Also on Autospeed. . . (Steve Arndt) (02-Jan-01 14:47:25)

How about run some alky? :-) (n/t) (Muffler Mike) (02-Jan-01 14:53:40)

Although that might only work good with a draw through where the alky cools as it is pulled into a vacuum. Hmmm now its got me thinking, wonder if it would still flow cool under pressure. (n/t) (Muffler Mike) (02-Jan-01 14:56:16)

It is cool when it evaporates. Hot or not when flowing, it gets cold when it evaps. (n/t) (Steve Arndt) (02-Jan-01 15:09:59)

Mike, you're stuck with Boyle's law - compress it and it gets hotter, which is why intercoolers were developed in the first place. (n/t) (george brown) (02-Jan-01 15:10:51)

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It depends on boost level and the temps you want to run I believe. From what I've read, I wouldn't think about a turbo system on a hot running aircooled engine without an intercooler if long life is wanted.

On the big engine I'm building I'm thinking of trying out Mark H.'s ideas. Build an engine that runs and works awesome by itself, then slap a turbo on this with low boost. This keeps it a nice driver on the bottom end retaining a bit of compression and having some real cam timing, but you can still get it on boost on the top end.

My engine is going to be 2.6 liters. I'm going to find an engine off a production car that was around 3.0 liters such as an older 300zx. This should provide the 8 PSI of boost I want at high RPMs but not boost much in the lower range allowing cool cruising :)

Remember to provide proper air/fuel ratios or you'll detonate and ruin the engine. Also around 1 degree of retard per PSI sounds close to right on the street. Run 30 degrees off bost, and 24 degrees when on 6 PSI. This can be done with an MSD 6BTM module. I am not going to turbocharge until I've installed an EFI ECU for injection and ignition.

Steve

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Here is the actual link.

http://www.autospeed.com/cgi-bin/browse.cgi?category=256&product=852&

A bonus to ordering is they give you a free six month membership to the online magazine/website Autospeed. They only provide about 1/10 of their articles as free to read, membership required for the others. As soon as my membership is instated I plan on reading for about 500 hours straight. They have an awesome site.

Steve Arndt

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They show how to take a cheap and widely avaiable intercooler such as on a Turbo 4 cyl mustang and build your own water to air intercooler. Cover the wimply little A to A intercooler with aluminum sheet and weld it all up with some fittings. This way you can pump water through the intercool and cool your air charge in a much smaller area. Bilge pumps or agriculture pumps work fine, or RV water tank pumps. You don't need to pump all the time. Wire in a radiator of some type, AC condensor, oil cooler, trans cooler, etc. Then use a boost switch and timer to run the pump, run it all the time, or build your own setup. Labtronics (available on Autospeed) sells a intelligent box which allows an in temp, out temp, and duty cycle (tapped off an injector harness) to determine an opperating window. Also if you have an ECU you can tell it to pump water when on boost above 1 PSI or something such.

Steve Arndt

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