Turbo replacement decisions...

[cometcyclonemk]

Introduced my problem in the welcome area, continuing it here...

I'll warn you, I can be very indecisive... But I'd very much appreciate any advice!

The problem:

Driving down the highway, started getting massive amounts of smoke out of the exhaust. Busy with school, etc - had to park the car.

Finally getting to the repair process. Removed turbo, found the crack in the exhaust side at the wastegate port, checked the oil drain line and it wasn't clogged. So I'm about 98% sure it's the turbo (and totally open to other thoughts on the matter).

If it is the turbo, it needs rebuilding / replacement - and that's where my problem lies.


My current setup: (mostly built by the previous owner, so a lot of it has been extracted from receipts):

Racer Walsh 2.5 Shortblock
Applied Technologies Header
Racer Walsh Hydraulic Roller Hot Street Cam
Head has had, "Comp Grind, Sufaced, Pocket Port" (with I believe, stock sized valves :( )

Adjustable cam pulley
3" downpipe, full 3" exhaust, no cat and Flowmaster single chamber muffler
LA3 Computer with 42lb injectors
K&N Filter on air meter
Factory Intercooler
Factory Throttle body (I have a modified 5.0 to put on)
Ported, gutted, knifeedged intakes (square style)
Walbro 255lph fuel pump
Adjustable fuel pressure regulator
Adjustable boost valve


Currently it has a factory 85 / 86 style water / oil cooled turbo on it. I keep it set at about 16psi (according to the factory boost gauge).

The dilemma:

Do I rebuild the stock turbo, or upgrade to something better? I'd really like to get something that can grow with my future engine modifications (I'd like to get to the 400 mark eventually), but my small amount of research and discussion with Charlie has led me to believe a turbo upgrade is a recipe for massive scope creep!

It seems as though most any upgraded turbo would require an external wastegate. My header does not have provisions for one, so that would have to go. Seems as though the Bo-Port is the only one known not to crack. It's $900... Then I'd need the wastegate... a couple hundred more... Modify the exhaust... Stock intercooler probably wouldn't fit (and probably doesn't make sense to still have)... etc etc.

So my question is, what are all you guys not running a stock turbo doing?

Recommendations on headers? Is the Bo-Port the only way to go? Wastegates? Any good arguments to keep me from dropping another couple thousand on my Mustang? :O

[Gyrhead]

So my question is, what are all you guys not running a stock turbo doing?

Garrett T3/T40E which Charlie astutely pegged would lead to massive scope creep; and it did.... including a BoPort ported head and 1.9 cam, Essy round tooth kit, a complete bottom end rebuild and lots more I can seem to recall at this hour. Ironically, my car was modded very similar to yours (except for my FMIC) before this turbo problem started.

[Stinger]

The dilemma:

Do I rebuild the stock turbo, or upgrade to something better? I'd really like to get something that can grow with my future engine modifications (I'd like to get to the 400 mark eventually), but my small amount of research and discussion with Charlie has led me to believe a turbo upgrade is a recipe for massive scope creep!

It seems as though most any upgraded turbo would require an external wastegate. My header does not have provisions for one, so that would have to go. Seems as though the Bo-Port is the only one known not to crack. It's $900... Then I'd need the wastegate... a couple hundred more... Modify the exhaust... Stock intercooler probably wouldn't fit (and probably doesn't make sense to still have)... etc etc.

So my question is, what are all you guys not running a stock turbo doing?



First you need to verify the source of the smoke. Finding a crack in the exhaust housing doesn't mean anything. I'd say 99% of the stock turbos are cracked there and don't smoke. Do a compression test to verify it's not a headgasket, look at the plugs to verify there isn't any oil on them, and check for oil in the downpipe or down elbow of the turbo.

As long as you get a properly sized turbo that has a "performance" exhaust wheel that is not clipped (I repeat, do not clip the exhaust wheel), it will perform quite well on your current setup and will allow you to turn it up substantially without having to purchase another turbo. Once you upgrade the turbo, the next thing holding you back will be the stock LA3 and air meter. Once you are ready to exceed around 300rwhp, you'd be best off to upgrade the ecu in some way (there are a handful of options).

If your goal is 400hp, the cheapest option would be a TO4E 50 trim compressor and a Stage 3 exhaust wheel (not clipped) in a .63 a/r exhaust housing. This turbo can be purchased brand new for $700 or less if you shop around. Just make sure you don't get a Chinese copy (they are about half price which is the easy way to know if it's genuine or a copy). You get what you pay for with turbos. Also do not get a TO4B compressor wheel (S trim, V trim, H trim, etc.) as they are very old technology and aren't very efficient at the boost numbers we run. They also tend to surge at tq peak because of the compressor wheel design.

If your eventual goal is 400hp, your scope is already creeping towards a number of upgrades (including the turbo) to reach your goals anyway. Buying a larger turbo isn't going to change what it will take to reach your goal (except you'll be one component closer since you'll have the turbo).

[cometcyclonemk]

Sorry for the long delay, had a chance to go to Speed Week @ Bonneville with my boss and couldn't pass it up :)

It happened suddenly under zero boost driving down the highway at normal temperature, I checked the plugs at the time of the incident, and they were fine. Oil was in the elbow...Unfortunately I don't have the necessary tools to check compression... If that's really a likely culprit I can get them, but I'm still thinking it's the turbo.

I think I've decided to upgrade to whatever I can reasonably do without doing the intercooler / header at this point. I really should swap out the rear end, and do some more suspension / chassis upgrades before I get to that kind of power anyway. This will also allow me to drive it for the rest of the summer before starting into those other projects.

Any recommendations for a mild upgrade turbo with internal wastegate that will work with a stock location header / stock intercooler? Just a rebuild / upgrade from Charlie?

Thanks again!