How To Build custom Turbo

Does anyone know a site that shows how to build a custom turbo? after reading all the sucess about them and the amount of money they save over turbo kits, i'm deciding i'll go custom. but first i got some questions to asks:

1. what do i need in order to run a custom turbo? this will be for a b20Z engine.
2. where does the BOV vacuum hose connect to? i know it connects to the intake manifold but where?
3. for the wastegate, is there any lines i need to connect it to besides just bolting it on to the exaust manifold?
3. is a MAP sensor required? if so, where does it go?
4. where does the oil line connect to? i heard there is a water line too. is it required?
5. how about the turbo timer? i want to get the TurboX timer that is not electronic. i don't like working with electronics item other than the boost controller. so how would i install this?
6. speaking of a boost controller, i'm planning to go with the greddy controller. what wirings do i need to do?
7. any other things i need to know so i don't miss out on any important stuff? oh yea, i'm planning to run 5lbs until i upgrade the fuel and ignition system.

please take time and answer this carefully because i don't want to mess anything up. hopefully the mods will make this a sticky so other people can look at it if they're in the same situation. thank you for donating your time.:)

Originally posted by GSteg
Does anyone know a site that shows how to build a custom turbo? after reading all the sucess about them and the amount of money they save over turbo kits, i'm deciding i'll go custom. but first i got some questions to asks:

1. what do i need in order to run a custom turbo? this will be for a b20Z engine.
2. where does the BOV vacuum hose connect to? i know it connects to the intake manifold but where?
3. for the wastegate, is there any lines i need to connect it to besides just bolting it on to the exaust manifold?
3. is a MAP sensor required? if so, where does it go?
4. where does the oil line connect to? i heard there is a water line too. is it required?
5. how about the turbo timer? i want to get the TurboX timer that is not electronic. i don't like working with electronics item other than the boost controller. so how would i install this?
6. speaking of a boost controller, i'm planning to go with the greddy controller. what wirings do i need to do?
7. any other things i need to know so i don't miss out on any important stuff? oh yea, i'm planning to run 5lbs until i upgrade the fuel and ignition system.

please take time and answer this carefully because i don't want to mess anything up. hopefully the mods will make this a sticky so other people can look at it if they're in the same situation. thank you for donating your time.:)

1. all the parts, turbo, manifold, BOV, wastegate, piping, lines and fittings, fuel solution

2. any vacuum source from the intake manifold, most people "T" it from the fpr vaccum source

3. a line from the side port to any vacuum source from intake manifold, top port goes to an electronic boost controller, other wise leave the topopen if you don't have an EBC...

4. the oil line can be connected to many different places. most common is the oil sender unit in the back...you will need a 1/8npt "T" fitting for it...also a 1/8npt into -3an flare fitting too. AS for the water lines, they are not needed, but I suggest you use them if provided with turbo(only on some applications), you just tap into any coolant line existant in your motor.

5. Turbo XS does not have a timer, just boost controllers and BOV's, for the timer harness though, each manufacturer has different ways, read the instructions

6. again, read the instructions...too much to write down. There are some links that show you, but I forgot them.

7. nothing much, except the fact that you'll want at least a 2.5" all the way out form the turbo....I reccomend 3"out, but you'll have to get rid of some accesories like AC and stuff, but it's up to you. Get rid of that cat.

any more questions, feel free to ask

oh yeah, be prepared to spend some time on the piping, especially the downpipe...

DOnt forget that there will be welding involved, so have a welder ready...

don't forget the intercooler:D

y would i have to get rid of the A/C?

You may have to get rid of the A/C to make room under the hood for the turbo, intercooler or any of the piping.

Custom turbo kits are a pain in the ass.
Much easier to just buy a kit and upgrade.

you dont have to remove AC to fit a turbo+manifold into your car unless you're trying to stuff a T88 into a CRX with a B16.

for the manifold, you can custom make one, buy a custom one, or buy a mass manufactured one for about $400-500.

i'm currently in the process of installing a custom turbo setup... Garrett T3 with internal wastegate on an F-Max manifold, custom downpipe, Vortech FMU, and stock Efini intercooler all into a 1997 Prelude.

just to clue you in, i'll be using silicone hoses and clamps for all piping connections with custom fabricated piping at 2.5"o.d. the intercooler will reside where the stock intake resonator used to sit, with an FC3 RX-7 intake duct to channel the air over the intercooler.

the F-Max manifold will be used due to saving on headaches and allows AC to be kept. the external wastgate port will be sealed with a handmade plate steel cover and removeable for future use.

the downpipe will use a Saab flexpipe i got for $10, and the piping will be 2.75" stainless to match the flexpipe diameter. the cat will be kept until i can find a legit source for an O2 sensor simulator.

Vortech FMU with 12:1 ratio, and rebuild kit for 10:1 ratio in case it doesnt need the extra pressure to maintain proper fuel ratio.

Missing Link MAP sensor check valve.

Apex'i blowoff valve

spring and ball valve hooked up inline for boost adjustment until i get the Apex'i AVC-R in my hands.

lastly, dont forget a clutch. depending on how much more power you'll make over stock at your desired boost level, you'll possibly polish your clutch friction disc on the first run.

whats the difference between an internal wastegate and an extranal? which one works better? which one is cost effective and easier to work with?

as for the a/c, it depends on which way you mount the turbo...most honda guys mount their compressor on the tranny side, so you can still fit it in without removing the a/c(if a 2.5" or smaller downpipe is used). But if you mount the compressor on the driver's side, you will have to get rid of the a/c compressor to make room....

"whats the difference between an internal wastegate and an extranal? which one works better? which one is cost effective and easier to work with?"


well, hopefuly if I'm wrong Ill be corrected 'cause the last thing I wanna do is pass along bad info. I believe that the internal wastegate comes mounted on the turbo. an external wastegate would be mounted on the exhaust manifold I really don't think theres much of a difference, just that one comes w/a turbocharger and if not, then you need to buy one and make sure your manifold has a mounting point for it.

When you install your intercooler piping, I'd use high temp painted various mandrel bends w/rubber connections and pipe clamps. You can use silicone but it might cost more. You can get an idea of the type of bends you'll need buy looking at manufactures web sites. Check the kits for your car and make note the the bends they use. Hope this helps

so if i get an external wastegate, do i just bolt it on to the exaust manifold and call it done? or do i have to attach some sort of hose to it?

Internal wastegate cannot handle severe boosting compared to an external one.

as for hoses on the external wastegate, side port to i.m. and top port to EBC

whats the difference between an internal wastegate and an extranal? which one works better? which one is cost effective and easier to work with?


The difference between an External Wastegate and an internal wastegate, is the External Mounts on your Exhaust manifold, and when boost pressure is in need of release, the External Wastegate vents the exhaust into the atmosphere....as opposed to an Internal, which routes the passing exhaust back into the downpipe!........The external wastegate is extremely loud and may turn some heads, but not in the way that we're all loking for!!.......Ha Ha! I've built a custom turbo kit from scratch for my Teggy! Got any questions E-mail me and I'l be Glad to help.

Removing parts like the AC condensor will vary from car to car. On my cars platform, in order to use a front mount intercooler, the AC condensor must be removed to make room for the piping. Needless to say, a water/air intercooler is used instead. Less lag too.

holy batman.


talking about bringing up a thread from the past


oh the things u learn over the ears :D

Just in case some who is reading this is interested http://www.cse.uconn.edu/~yelevich/turbo/turbo.html