Wastegates: internal vs external

[technician163]

I'm new to the turbo world and just recently picked up a 1991 turbo talon awd 5 speed for $250. I am a skilled and experianced mechanic in the south central region of PA. We don't see many, if any turbo cars, so this is releatively new to me. My question is: is there much of a difference between the internal and the external mounted wastegates??

 

[talintidturbo91]

I believe i was told that with an external wastegate you get boostcreep?

 

[VETTE_50_TH]

One hell of a lot of difference. External, you have more control of the boost. Different options to mount and places to dump. Same can be said for internal except the control of boost. Internal you see a lot of people creeping and spiking. I run a external off the first runner and people say thats the worst to dump from, but to be honest, i never go over 10 pounds, which is what its set at. I love my Tial and never will go to anything else. I dump back to the o2, but i can dump to the atmosphere if i want to.

James

I believe i was told that with an external wastegate you get boostcreep?

Spin again Vanna.

James

 

[talintidturbo91]

what i meant is don't quote me on it. as i don't know everything.

 

[VETTE_50_TH]

what i meant is don't quote me on it. as i don't know everything.

Well now you know. Externals are much better. With some, you can adjust when the cracking time of the external is, and the biggest thing is, you dont have to worry about it not opening when its suppose to. Its like the best insurance you can get on your turbo.

James

 

[1992awdlaser]

The external wastegates will control boost much better. I have mine off the cylinder number 1 runner and have no problems.

 

[technician163]

ok, well 2 more questions that I ment to originally add: 1. can u mount and external wastegate and disconnect the factory one?? 2. I'm looking at headers on ebay, and wondering if the factory turbo can be bolted to a headder, or if I need to replace the turbo?? I have a lot of room for improvements as the car is completely stock and has 93,000 miles on it

 

[talintidturbo91]

I always wanted to get an external, but i was told internal was better??? well now i know and i am one answer smarter. you learn something new everyday!

ok, well 2 more questions that I ment to originally add: 1. can u mount and external wastegate and disconnect the factory one?? 2. I'm looking at headers on ebay, and wondering if the factory turbo can be bolted to a headder, or if I need to replace the turbo?? I have a lot of room for improvements as the car is completely stock and has 93,000 miles on it

i do know one thing, they're not called headers. they're called manifolds. and yes as long as it is for the stock turbo.

 

[1992awdlaser]

You can either weld your internal gate shut and put an external on the manifold. Or you can take the internal off and put an external in its place with a different o2 housing. Give us a link to the "header" you are looking at.

 

[silver bullit]

Internal is cheaper (comes stock on dsm) but some boost creep can happen.
External is better but not cheaper(more expensive cause you need a waste gate, a place it is mounted manifold, off the 02 housing etc...)

If you do go external get a good quality one dont cheap out for ebay casue if you do and you get a knock off hey i warned you now you can replace your motor.

Make sure that it centralized on the manifold,
IE:
If it is mounted on the middle of runner number 1 then when the waste gate opens then exhaust from 2,3,4 runners has to go to the center then double back to 1 to let it off.

 

[VETTE_50_TH]

You can either weld your internal gate shut and put an external on the manifold. Or you can take the internal off and put an external in its place with a different o2 housing. Give us a link to the "header" you are looking at.

This is true. However, the fact that you go from a 30 mm to 38mm or larger is something to i wouldn't want to do. I would weld the factory gate closed, and dump off the manifold like awdlaser and I do.

James

Internal is cheaper (comes stock on dsm) but some boost creep can happen.
External is better but not cheaper(more expensive cause you need a waste gate, a place it is mounted manifold, off the 02 housing etc...)

If you do go external get a good quality one dont cheap out for ebay casue if you do and you get a knock off hey i warned you now you can replace your motor.

Make sure that it centralized on the manifold,
IE:
If it is mounted on the middle of runner number 1 then when the waste gate opens then exhaust from 2,3,4 runners has to go to the center then double back to 1 to let it off.

I would really like to setup a lab in my physics class when i take fluid dynamics to prove this theory of the exhaust from the other runners going to the first runner. I would really like to see that and how it acually happens. Mount the manifold up to a flat surface, setup a Tial wastegate to open at a specified psi, and color the air from each runner different going through the manifold so you can tell where its coming from and see how much air from the other runners comes through the wastegate.

James

 

[technician163]

hey guys, here's a link to the manifold i am looking at. what is the port on the side for??
eBay Motors: ECLIPSE,TALON,1G,2G DSM,TURBO MANIFOLD HEADER,T3/T4 (item 370029552618 end time Mar-10-08 13:27:29 PDT)

 

[90GSTBoosted]

I would veeery strongly suggest you stay away from those "manifolds" unless you are ready to buy a new one after a month when this one has sagged from the heat. You have no idea how crappy these are. The welds are crap and the metal they use is very thin. Again, I would stay away from these if I were you. A decent manifold cannot be bought for less than $300 if brand new, keep this in mind. Everything else, in new condition, for less than 300 will be crap. I would buy something used but proven.

 

[1992awdlaser]

I would stay away from that manifold. If you are on a budget just get a stock 2g manifold. The port is for an external wastegate.

 

[Mr Peepers]

I would veeery strongly suggest you stay away from those "manifolds" unless you are ready to buy a new one after a month when this one has sagged from the heat. You have no idea how crappy these are. The welds are crap and the metal they use is very thin. Again, I would stay away from these if I were you. A decent manifold cannot be bought for less than $300 if brand new, keep this in mind. Everything else, in new condition, for less than 300 will be crap. I would buy something used but proven.

You can't judge something by its price alone.

BUT I can tell you that won't bolt up to you're stock turbo with a t3/t4 flange. Even so, it would barely benefit your stock turbo anyway. A better route would be getting a ported 2g exhaust manifold.

Follow this for ideas on what to upgrade. Certain things must be done before others, especially if you want to see a gain at all.
Tech Guide: 1G 4G63t Upgrades - DSMtuners

Oh yeah,
An internal WG is what you have on your car now. It's a valve on the turbine housing(exhaust side) that bypasses exhaust around the turbine. Control how much and when it opens, and you have control over boost.

External WG's are wastegates that are mounted outside of the turbine housing itself. The valve is generally larger and can bypass more exhaust (along with some other reasons) than an internal gate, and boost creep is caused by a lot of exhaust needing to be bypassed at higher rpm. They don't tend to "blow open" like internal WG do at high pressures and tend to have better boost control. These are usually fitted on much larger turbos than a stock 14b, and will serve no purpose at all. If you did have creep(you won't with stock exhaust), there are MUCH more cost effective ways of handling it.

Not a bad looking car for $250

 

[VETTE_50_TH]

The guy says ported for huge gains. Wtf. You shouldnt have to port that thing. And also, did you see the bolts that he gives you. Looks like he went to Raul's discount hardware store to pick up those lame as bolts. And like peepers said, its a t3/t4 housing. You have a mitsu housing, good luck with that. That thing is a no no.

James

 

[gsxAWDdsm692]

The only real pro of an internal wastegate is it is quieter then external if routed back into the exhaust.

 

[VETTE_50_TH]

What? Never heard that one. How can that be possible. If they both go to the same place, and both open at the same amount of boost, how can one be quieter than the other? I dont understand that one. WTF

James

 

[Mr Peepers]

You can reroute an external as well. The benefit is cost.

 

[gsxAWDdsm692]

What? Never heard that one. How can that be possible. If they both go to the same place, and both open at the same amount of boost, how can one be quieter than the other? I dont understand that one. WTF

James

If your running atmospheric is it going to be louder or quieter then if it is routed back into the downpipe?

 

[VETTE_50_TH]

Sorry, thought you meant both to the downpipe. Yea, running to the atmosphere is MMMMMUCH louder than back to the exhaust system.

James

 

[TSi_with_psi]

technician163, I'm just wondering what your reasons are for wanting a tubular manifold, or a external wastegate? Simply adding a tubular header to a stock dsm will net you very little power gain, if any at all. The same goes for an external wastegate. Since your car is stock im assuming, there would be no real reason to upgrade the wastegate yet, unless it is causing you a problem. I would highly recommend that you follow the upgrade paths at Tech Guide: 1G 4G63t Upgrades: Stage 1 Power - DSMtunersGood luck!

 

[technician163]

wow!!, being a newbie, I am very impressed with the posts on this topic and I would like to thank everyone for their input. My main reason for the tublar manifold was curriosity, but aside from some very minor dents, this car has only one flaw-- the previous owner was a drug addict and knew nothing about cars. He cut about 2 feet of the exhaust off of the car to remove the cat and turn it in for drug money. That being so, I would like to replace the exhaust from the turbo back with 2.5" exhaust. I'm wondering if the bigger exhaust is going to cause me any problems with "boost creep". Thank you for the tip on the stage 1 upgrade list, I am going to follow that as a guide. Also, how important is the 190 lph fuel pump?? My plans are not to exceed the stage 1 upgrade other than adding some hard intercooler tubing and a fmic(they just look cool as heck) and possibly a BOV?? any suggestions on brands of BOVs?? Thanks to everyone again!!

 

[VETTE_50_TH]

Better check that car for weed. Get pulled over and the sniffer dogs with ruin you for life.

James

 

[Mr Peepers]

Use it to pay for mods.