internal and external wastegate, what the difference?

kroz123 · Post by **kroz123** » Mon Jun 26, 2006 2:57 am

which would be better to get for a stock engine?

Cuz I saw that there are different turbos that have an internal wastegate set to 6psi, but I don't want that cuz I prolly not going to run it at 6 psi all the time.

any pointers would be great cuz my knowledge of turbos is not that big yet.

Thanx

Arvin

Post by **PrecisionBoost** » Mon Jun 26, 2006 3:31 am

externals are more efficent and have better adjustment for larger turbo systems.... for small boost turbo systems... internal wastegates are very nice since less fabrication is required.

MMamdouh · Post by **MMamdouh** » Mon Jun 26, 2006 7:25 am

i think with internal wastegate that is not adjustable - like the one set to 6 psi - you can get a manual boost controller to set your own boost level... some internal wastegates are adjustable so you can set it to whatever boost level you want... look for threading and a fastning bolt on the wastegate's axel.

MMamdouh

kroz123 · Post by **kroz123** » Tue Jun 27, 2006 1:35 am

I think I'am going to buy a turbo with external wastegate cuz I can adjust it the way I want.

M I N I O N · Post by **M I N I O N** » Thu Jun 29, 2006 8:23 am

AS said before, you can adjust internal wastegates as well. There are kit available with a die an threadable arm which you can screw in to make the arm as long or short as you want to adjust teh tension on teh wastegate. Most external wastegates, you need to change the actual spring inside of them to lower the boost level, a boost controller can bring it back up. This is much better for on-the-fly adjustments.
External wastegates also do a better job of regulating the boost levels. At high RPM, internal wastegates will give you something called boost creap, where the exhaust gasses coming from your engine are bottle-necking in the wastegate port and start to go through the turbine again, increasing the boost level.
There is also something called a spike, where the bosot levels will shoot past your desired boost level and then fall back down as the wastegate has a hard to keeping up with the demands put on it so suddenly.
I'm using a 40mm external wastegate from HKS and I love it:

Nubira2.2 · Post by **Nubira2.2** » Thu Jun 29, 2006 10:42 pm

HKS parts are too expensive

M I N I O N · Post by **M I N I O N** » Thu Jun 29, 2006 11:50 pm

If you shop around you can find decent prices. I have a pretty good hook-up through HKS. I only paid $200 for my 40mm wastegate and $180 for TWO ssqv blow-off valves. All brand new in original HKS boxes, not knock-offs. Unfortunately I can only get parts at cost from them for my own car and I have to prove that I am using them.

Nubira2.2 · Post by **Nubira2.2** » Fri Jun 30, 2006 12:08 am

u see thats the thing

i would love to use HKS, GREDDY, Turbonetics, TurboXS, TurboSmart, Garrett and other well known brands

but they are expensive

and if i only want 6 psi to have good power on the streets

is it worth spending $255 on a BOV and $400+ on a waste gate ?

then u see very cheap parts on eBay that makes u doubt if they really work

thats why i am now considering OEM parts from other cars

like EVO BOV, NISSAN MITSUBYSHI internally gated Turbos and things like that

what u recomend MINION ?

M I N I O N · Post by **M I N I O N** » Fri Jun 30, 2006 12:25 am

Well the Audi s4 uses an external wastegate of fairly high quality that will regulate you to 11psi. I found a write-up a while ago where they took apart the top vacuum chamber and added a few components to make the spring rate adjustable through the use of a bolt. You can also jsut buy different springs to lower the boost of that wastegate. In the end though you may be paying as much as you would for just a used Tial wastegate. I would personally recomend going that route. Find a quality part used on ebay before you buy a cheap part new.
For the blow-off valve. You can pick up a 1st gen DSM bov from a junkyard for just a couple bucks. They are very comonly used and don't leak boost between shifts. Since they are so common, aftermarket companies make flanges to put them on other charge pipes.

For a turbo, your best bet is to do some compressor mapping and find what cars have a turbo based on your end results. If it has never been discussed on this board, please let me know and I will make a nice long write-up on compressor mapping.

Nubira2.2 · Post by **Nubira2.2** » Fri Jun 30, 2006 3:40 am

thanks

for the info

my project is just few months ahead and ass son as i get some money i will start buying things

i will let you know