Came up on a TB305 Garrett originally used on a 301 Firebird. Paid $50. My question is, what must I do to convert this unit for it to function on a b18b motor? Is it even possible?


1) IF possible, is there a 3 bolt to 4 bolt conversion for the intake ports/turbo exhaust manifold?

2) Do I need to swap the compressor to a "blow through" compressor? Or will this TB305 compressor work the same?

3) Because this turbo is originally intended for a carb engine does that mean it can't be used for a throttle body injected motor?.

4) Is this a lost cause and should I opt for a different turbo?

 

1) No. None available.

2) Normally a blow-through is needed to work with supplemental equipment.

3) Not necessarily, but you'd basically have to make the parts for this to work.

4) Yes, it is a lost cause, and you should opt for a different turbocharger. Just because it was cheap, doesn't mean it is useful.

 

Man that turbo had trouble written all over it. Too much going on not to mention it looks like it's been Sitting since 1987. Not being a dick but cut your ties and move on

 

Turbo is good mechanically considering the age. It's a TB305 Garrett. No shaft play. I bought it because I figured it was functional and the price was reasonable and with a some custom work figured I could make use of it.. Has an internal wastegate. Stock 8-9 psi setting. Capable of 20+ psi, from what I've read on other forums. Thought maybe I could make it work on a b18b engine by connecting the 3 bolt flange(on the turbo) to a custom adapter thats compatible to a t3 (4 bolt) turbo manifold...

Which parts would I have to "make" for this to work? I know there are modern/newer turbos available. ..but if the condition of the turbo is legit and if it has been done before what would I really need?

 

GET A DIFFERENT TURBO....Theshodan is possibly the most knowledgeable person on the site as far as turbos go. His answer was pretty cut and dry and with reason. There are no adapters available to make it even work for a Honda. It would have to be custom machined. So would you pay $1000 to make an old and odd turbo work? I hope not. Shaft play isn't the only thing to worry about. Reason I said it looks old and like it sat is because you have a metal item that sat and who knows what the internals look like anyway as seals and bearings.

External gates are better for adjustability and high boost levels.

 

TheShodan's answer to my 3rd question lead me to believe that there's a possibility still that this turbo could be used if all it takes is buying flanges and fabricating/making custom parts to allow the turbo to fit onto a turbo/exhaust manifold or changing/replacing other turbo components in general. Im sure it wouldnt cost me $1000 because welding isn't a problem for me all i would need is materials and I can have the work done.

Btw, I understand he is more knowledgeable...I wasn't questioning it. I understand there'd be parts that I'd have to custom make to make things fit and that's okay. And if internals must be replaced on the tb305 then that's okay too there are rebuild kits. I'm also aware of the wastegate being internal and the difference between internal and external. Regardless, that's not a problem because this turbo could be converted to external wastegate by buying an exhaust flange/plate that will block the wastegate "flapper" hole. I know I probably come off as stubborn but I am mostly trying to learn the design of the turbo to see how I could make it function on a B18B if possible but apparently it has never been done hence why I'm not getting any real details. Until I get a definite "no its impossible" I'm not going to ditch the idea.

 

Nothing is impossible.
This idea is however very impractical. What you have there is a turbo that will never be in the realm of being able to compete with modern units in the $500-600 range. The early Garett's are far from efficient, and very problematic. By the time you spent all of your time and money rebuilding this unit, fabricating the necessary hardware, etc. you could have taken that money and just bought an inexpensive new turbo that will be more efficient in every way, and then have the engine running as opposed to chasing this old slug.

 

Sounds like your set on using it. So fab every part yourself and do it. It would cost $1000 for someone else to make a custom manifold and down pipe for your car is what I meant by that. It's just a lot of work when u have soooooo many turbo options. Good luck. So what exactly did u want us to answer?

 

Do you realize also that the turbo your wanting to use will probably max out around 300hp too? These units made under 200 whp on a 301 CID V8 @ ~10psi. Also, these old oil cooled turbo designs need a steady diet of high oil pressure to survive. (Atleast 55-60psi when in boost minimum.) Keep that in mind as well if this is to be a street build.

 

I apologize if I seemed to give false hope. I merely made my statements without sounding obtuse or to express any absolutes. I don't know your abilities nor your resources available to you, so I don't like to make specific presumptions. The solutions to your inquiry are much more than simply finding or making specific flanges and components to work with this unit.

In addition. Simply finding a "rebuild kit" may be easy thanks to eBay, but that does not mean that it is of quality materials (at least enough to warranty a full tear down) or that it may solve any potential problems that this turbocharger may have experienced in its former days.

What one has to consider more than anything is not just can something be fabricated, but for all practical purposes, should it be done. My answer to this is a resounding no...as a practical matter.


This is also something that you want to factor in when it comes to your cost-benefit analysis. There's a LOT of support for universal fitment that is much more cost effective than trying to retain value with this current $50 turbocharger. What I've found is that when you get something that "rare" for that low type of cost, its usually because the seller couldn't do anything with it either.

However, without being redundant, I share B20VtecVillain's summation

 

Make your life easy and cut your losses. This $50 turbo just isn't worth the headache for 99% of people but hey, maybe your the 1%er

An accurate example would be finding a type r grille for a 97 civic for cheap but you have a 99 front end. Would you change the lights, fenders, bumper and hood just to make that great deal of a grille work? Seems crazy doesn't it?

 

Rebuild kits are available. There are reliable sources for quality rebuild kits. 6 hour job for a "back yard" mechanic. OR, I could have the turbo shipped to one of the "source" who will rebuild it for a fee (assuming the turbo is too old to function right now).. The casting/casing(s) are good.

Anyways, thanks for the input. By the looks of it it's not "salvageable" or "reusable" so might as well go to the bar and drink a beers and relax and forget(contemplate) my car endeavors for a bit. Lol

 

You still have options your just better off not using this particular turbo, you will save money in the long run. Just resell it I mean your only into it $50 so not a huge loss

 

Noooooooo. He's gonna go have a few and a local town clown is going to tell him it's the best turbo ever. Then we'll see the 25hour build thread for this custom manifold and down pipe. Lol.

I'm just playing. You have come to your senses and will be happy in the long run

 

Honestly if you were good at fabrication you could make anything work. But this thing looks like it would be a bitch.

 

should have saved your $50!

 

Once upon a time, this guy baught an item off of impulse. That guy ended up waisting his time and money. Moral of the story? Check your pulse.

 

^check you pulse? What does that even mean?

Also the only difference between a standard turbocharger and one designed for a draw through application is the design and material of the compressor side seal. Back when this class of turbochargers was designed the standard compressor seal material being used at the time wasn't rated to survive long term contact with gasoline and gasoline vapors, something the seal constantly comes in contact with in a draw through setup. So Garrett revised the seal material to a carbon based seal for gasoline use and redesigned the arrangement of the seal to minimize its exposure to gasoline.

I once heard someone say that the aerodynamics of the wheel were modified over the standard turbocharger in an attempt to prevent atomized gasoline from "sticking" to the compressor wheel and accumulating inside the compressor housing volute during low airflow conditions (idle, off throttle decel, etc) but I could never confirm it online and shy of physically inspecting the wheel I still couldn't verify it.

If you look at how the compressor housing was clocked for the original application then you'll notice why the compressor outlet is the lowest point and pointing downwards. This was to give any fuel that might accumulate within the compressor cover a way out before any significant volume of fuel could build up which would cause all sorts of issues if it entered the intake manifold all at once.

If you are dead set on using it then there's nothing you need to do to the unit as far as tearing it apart unless you plan to rebuild it. The different compressor seal has no issues not being a draw through setup. As far as the compressor inlet and outlet goes you have a few options.

The inlet: either find a gasket and send it to someone with a water jet and have them cut out a flange or simply have someone weld a piece of aluminum tube to the inlet. That way you can use a standard coupler and clamp

The outlet: have someone cut the OE flange off while at the same time squaring the outlet off then have someone weld a piece of aluminum tube to it and again use a standard coupler and clamp.

All pipe should have the same inner diameter as the inlet and outlet.

The other thing you can do is clean up the carburetor/intake piece and sell it. I've seen a few people before asking for that piece so they can turbocharge their pontiac. The turbocharger *might* let you reach 250hp or so but that would be it's limit. The wastegate was factory set at 7psi but people have run them over 20psi. With no compressor map it's hard to gauge performance but I would say don't run it much over 20psi. Given what size wheels it should have then even at that point it should be fairly inefficient with high compressor outlet temps.

Upon searching I found one kid who thought the TB305 was "******* enormous" and another guy swearing it was a 500hp turbo. I can't help but laugh my *** off at those people like do you have any clue what you are talking about? The internet never fails to make me laugh lol.

 

Check your pulse aka impulse. Didn't make any sense I know. Lol. My bad.

Appreciate the information. I believe I've done enough research for now on this Tb305 as far as it's capabilities and what I have to do to make it work. I think making an adapter from 3 to 4 bolt for the turbo manifold would be the hardest part since there isn't one available. Worst case scenario though is I opt for another turbo which I already have available through a buddy of mine. He has an eBay turbo with Garrett internals. 50 trim. Should be able to cop that from him for a legit price. If not that snail he has 3 other one's that are more potent but for more money obviously. I'd like to be up in the 220-250whp range more or less and no more than 8psi-10psi preferably. I don't care too much for "alot" of horsepower I just want boost again and hopefully be able to run at least a 13(ish) in the 1/4. I used to own a 93' hatch,b18c1, 8 psi, Garrett T3 about 4 years ago. Wasn't the "fastest" but I enjoyed the car a lot. Since then none of the cars I've owned could match it speed wise. So I'm looking for the smallest most efficient turbo for my set up, using 450 cc injector as well as all the other "supporting" mods to finally have boost again. Im not buying a kit either. Piece by piece. I have b18b1 head and a block that through a rod also. I'd like to find myself a bare block and rebuild it(oem spec most likely) and add all the arp jazz and call it good after that until I decide I want more boost in the future.

 

<p>It sounds like OP has made the smart decision of not using this thing, but just for my own information...Correct me if I'm wrong, but isn't a draw through mounted between the carb and the head? &nbsp;That would expose it to fuel, and even if that turbo did look good, those seals constantly exposed to gas...they can't be in good shape.</p>

 

As far as I know from what I've read on other forums this turbo needs to be rebuilt and needs to have the compressor/housing completely swapped since, like already mentioned, during the entire life of this turbo it has had fuel running through it. The only "good" thing about this turbo is the fact that there's very little to no shaftplay and it came with the "plate" that attaches to the carberater..Regardless, it's more than safe to say that he turbo is "out of service" and needs to be refurbished anyways whether it was being used for a 301 Pontiac or my b18b engine. I'm convinced that it's pretty much too much of a hastle. Plus I can't confirm that's its been altered to work so it's probably in my best interest to smoke some of my legal matter and just forget about it!

 

That's what we've been telling you all along lol. Good decision though, you will be much more happy with a modern unit anyway. Throw a disco potato on that thing and have a super fun, fast spooling street car!

 

I'm pretty sure that turbo uses a Stage 1 turbine wheel which means you could just buy an appropriate housing. Lots of OEM 80s/90s turbo cars used T3 Garrett's with the Stage 1 turbine wheel. The reason being that the physical size of the wheel and it's aerodynamic profile were a perfect fit for the power curve they were trying to produce... Minimal lag with lots of low end torque and midrange horsepower while showing minimal gains up top. They were basically trying to get a smaller displacement engine to feel like a larger one by producing as linear of a torque curve as possible (makes an inline 4 feel like a v6, v6 like a v8, etc) while still maintaining fuel economy and emissions regulations.

Take a picture of the turbine wheel and if you can remove the turbine housing and measure the wheel. Since it's doubtful that housing has been off it will be a bitch to remove. Use lots and lots of penetrating oil (not WD40 but something like PB Blaster penetrating oil ((they make a dedicated penetrant)), DuPont liquid Teflon (the bees knees if you can find it) while heating the area where the CHRA and housing meet. Typically after that it will pop off with a few good whacks from a rubber mallet or you might have to clamp the CHRA in a vise and use a pry bar to get it loose.

Remember I do accept turbo donations lol I

At minimum I would pull that carb mount off, clean it up real well, gasket match the ports (more efficient airflow and a selling point for more money), and toss that bitch on eBay. With the proper title, description, and photos you could easily make your money back and then some.

 

^^^ Says that guy that basically hordes everything that rotates over 20,000rpms and yet still gives lost hope.

 

Lol love ya :p

I'm just saying if he's hellbent on running this and it has a Stage 1 turbine wheel then there's an easier way to solve the turbine flange problem. Granted this unit really isn't worth the time or effort. At the very least he would be much better off buying that bastard turbo from his friend.