Upgrading a T3 turbo to a T3/T4-What's involved?!?

[MarkEmark]

Before I intercool the KA this spring and have all new piping fabbed up, I may upgrade the compressor on my T3 super 60 to a T4 (or T04E, or whatever bolts up to the T3 turbine), and I'd like to know exactly what's involved in doing this.

I want to keep the T3 turbine because I like how its low .48 a/r allows really quick spool up and beautiful throttle response; plus, I don't want to change the turbo altogether for fear of the downpipe not fitting (and I just spent a lot of time a month and a half ago re-fabbing it).

So my question is:

a) What is involved in changing out the T3 compressor (.60 a/r), including both the housing and the wheel for a bigger T4 compressor or T04E compressor? Obviously I'd have to remove the turbo and unbolt the compressor housing, etc, but how do I actually change the compressor wheel? What's it held in by? Do I need any specialized tools to do it? I'll probably have the assitance of my dad, who's rebuilt turbo's before, but I don't want the upgrade to be a nightmare. I know the limiting factor of my turbo is the compressor wheel and the fact that it can't flow that much air; I just read a post by erich saying his built ka @ 11 psi with a T3 60 trim (almost identical to mine) only had 222 rwhp--and I want at least 20 more whp than that @ only 10 psi.

b) will upgrading to a larger compressor create more lag? Will it increase the RPM at which I achieve full boost and hamper throttle response?

c) I know there's different size T4's out there, and I'm not sure how big I should go. I'm going to be running 10 psi with a JWT ECU, 370 cc injectors, PDM stage II cams, walbro 255 lph fuel pump, intercooled, etc etc. I'm looking to maintain a broad powerband but also make some power up top. Currently my problem is boost drop-off past 5k rpm, which can be attributed to a variety of factors, perhaps even my MBC, but changing the compressor I believe will definitely help to gain some psi up top. Also, are T04E upgrade kits available that bolt right up to a standard internally wastegated T3? If so, where? Would a T04E 50 trim be better than a T4, say this one:

http://cgi.ebay.com/ebaymotors...09814

Any info would be appreciated, thanks.Marc

[C-Kwik]

Any T04(B or E) compressor wheel should bolt up to the existing turbine shaft. You'll want to use a T-handle wrench to loosen and tighten the bolt though, so you don't put a lateral load on the shaft and perhaps bend it.

The only parts you will need are the compressor wheel, matching backplate and housing. Other than that, it's pretty much a bolt on affair. You don't really need any kind of a kit.

As far as more lag, yes, a bigger wheel carries with it more rotational mass. But it won't be too bad. It'll probably be negligible. Just make sure to get an efficient compressor wheel. At 10 psi, the T04E-50 will work fine and leave you a ton of headroom if you decide to up the ante later. You'll be crossing through the 78% efficiency island at 10 psi, which is real good. Higer efficiency nets you a cooler charge. And the reason it does is because it's more aerodynamically efficient at that flowrate and pressure ratio so that means you need less torque from the turbine. This means your turbine can do less work, bypass more air through the wastegate and free up some additional power. This should help some with your loss in top end, but keep in mind, the T3 with a .48 A/R has been known to be somewhat restrictive on a KA at the top end. Going slightly bigger on the A/R can help without much sacrifice in response.

The T4 in the link you provided is a T04B S3. Peak efficiency is only 73%. It'll do the job well enough, but the range is limited and a little lower than other compressors. The peak efficiencies will only be seen between about 7 psi and 15 psi. Not as versatile as the T04E-50. If you're going to spend the money, I'd just assume buy a compressor that best matches your needs.

Keep in mind I run a full T04B. I have no complaints about lag. 1st gear is the only place it's noticable and even at that, it's not bad. A T3/T4 set-up I've driven was certainly more responsive, but hardly enough of a difference to be really concerned about. You tend to ignor lag when you make more power. I drove a lag monster of a Supra before. Off boost it felt a bit weak, but knowing what happens when boost hits, you will love the anticipation and the sheer thrust. I found myself with a heavy foot in that car just to get into the boost range. And as long as you kept the car in the power band, lag was only a problem in 1st gear. Lag meant nothing to the Z06 I raced using the Supra. Most people who complain about lag probably have never been in a car that has a huge turbo. Unless teh response needed is for a specific application, I don't hold it in such high regards as to want to sacrifice HP potential. But that's just me.

[MarkEmark]

Thanks for the detailed response. I'm glad it's more or less of a bolt on affair, but i'm not looking forward to removing the entire turbocharger from the manifold--for the fourth time

So--where can I find this beautiful T04E 50 trim compressor housing/wheel/matching backplate? (I'm assuming I can use all the bolts, etc from the existing T3 compressor).

C-Kwik-any pics/specs of your setup?!?

ALso, I know that 10 psi isn't too much and won't max out my T3 super 60 with the 370 cc injectors, but would using a T3/T04E make me run into some problems? I'll still have that "restrictive" turbine and only a 2.5" mandrel bent exhaust/no cat the whole way back, so I doubt I'll see a full 10 psi up to 6k rpm, but I'm just wondering. But, if my injectors truly are 400 cc, as they are according to RCEngineering, then I wouldn't have to worry about them--but what about the MAFS? I guess I'll worry about maxing that stuff out after I upgrade the compressor (if I do), because IIRC I need at least 250rwhp to max either of those entities out--and if I'm making that much power, I'll be extremely pleased.

[C-Kwik]

I have an XS-Engineering Kit. Find a pic of that and for the most part, that wil be my set-up. Though I run 370's with the E-manage. Also I run a different turbo than what came with the kit. I bought the kit used and it blew the first week. I would have picked out a better matched turbo, but since I had a T04B lying around that I pretty much got free, the price was right. I have pics of my set-up, but I don't have a place to host them. PM me or email me through the profiles page with your email address and I'd be happy to send you a few.

As far as finding the pieces, any Turbonetics or Garrett dealer should be able to help you.

[MarkEmark]

You don't need to send pics if it's a hassle, i was just curious.

[email protected]

I searched all through ebay/google and couldn't find any T04E upgrades (compressor wheel, housing, backplate), and I know the dealers are gonna be incredibly expensive....and I don't know of any around here anyhow.

Maybe I'll just go with that T4 I found on ebay--73% is still pretty efficient, and it'd be a lot better than what I have right now...

[C-Kwik]

Peronally, you have a turbo that works, so maybe just save up and get the best match. The unfortunate part about E-bay is that they tend to be the stuff that the seller doesn't want. While they may be a good deal, I prefer having a good match myself. But it's up to you. I'd do a little calling around. It should be much less than the cost of a brand new turbo. IIRC, turbonetics was selling T04 turbos with standard bearings somewhere around 700-800 MSRP. Dealers may be able to give you a better price than that as well. I wish I could find the price list I picked up at SEMA.

And you have mail.

[MarkEmark]

Any T04(B or E) compressor wheel should bolt up to the existing turbine shaft. You'll want to use a T-handle wrench to loosen and tighten the bolt though, so you don't put a lateral load on the shaft and perhaps bend it.

The only parts you will need are the compressor wheel, matching backplate and housing. Other than that, it's pretty much a bolt on affair. You don't really need any kind of a kit.

As far as more lag, yes, a bigger wheel carries with it more rotational mass. But it won't be too bad. It'll probably be negligible. Just make sure to get an efficient compressor wheel. At 10 psi, the T04E-50 will work fine and leave you a ton of headroom if you decide to up the ante later. You'll be crossing through the 78% efficiency island at 10 psi, which is real good. Higer efficiency nets you a cooler charge. And the reason it does is because it's more aerodynamically efficient at that flowrate and pressure ratio so that means you need less torque from the turbine. This means your turbine can do less work, bypass more air through the wastegate and free up some additional power. This should help some with your loss in top end, but keep in mind, the T3 with a .48 A/R has been known to be somewhat restrictive on a KA at the top end. Going slightly bigger on the A/R can help without much sacrifice in response.

The T4 in the link you provided is a T04B S3. Peak efficiency is only 73%. It'll do the job well enough, but the range is limited and a little lower than other compressors. The peak efficiencies will only be seen between about 7 psi and 15 psi. Not as versatile as the T04E-50. If you're going to spend the money, I'd just assume buy a compressor that best matches your needs.

Keep in mind I run a full T04B. I have no complaints about lag. 1st gear is the only place it's noticable and even at that, it's not bad. A T3/T4 set-up I've driven was certainly more responsive, but hardly enough of a difference to be really concerned about. You tend to ignor lag when you make more power. I drove a lag monster of a Supra before. Off boost it felt a bit weak, but knowing what happens when boost hits, you will love the anticipation and the sheer thrust. I found myself with a heavy foot in that car just to get into the boost range. And as long as you kept the car in the power band, lag was only a problem in 1st gear. Lag meant nothing to the Z06 I raced using the Supra. Most people who complain about lag probably have never been in a car that has a huge turbo. Unless teh response needed is for a specific application, I don't hold it in such high regards as to want to sacrifice HP potential. But that's just me.

Hmm...I'm starting to have second thoughts as to whether or not this is a bolt-on affair after talking with some people. Isn't the entire shaft balanced from the factory as a unit, including both the turbine wheel and the compressor wheel? I'd be surprised if I were able to remove the wheel myself if these things spin at 150,000 rpm--you'd think they'd have some special locking mechanism. I'm not trying to discredit what you say c-kwik, but have you actually done this before? Has anyone done this before? Do the two blades need to be balanced as a unit together? Is it actually just a bolt-on affair?

EDIT: Found some confliciting information on this thread on FA

http://forums.freshalloy.com/u...81702

Maybe it isn't such a good idea to do myself; and I don't know of any turbo places around here....

[C-Kwik]

It depends on if each component is balanced separately from the factory or not. If they are balanced as a unit, then there may be issues. But if each component is balanced separately, then it would probably be okay. Stan-O provides some good info in there. And as he said, if all peices are balanced individually, then the unit as a whole should be balanced when assembled. If you do not want to chance it, there are plenty of shops out there that can rebuild and balance a turbo assembly. You might have to ship it, but they are out there.

[MarkEmark]

It depends on if each component is balanced separately from the factory or not. If they are balanced as a unit, then there may be issues. But if each component is balanced separately, then it would probably be okay. Stan-O provides some good info in there. And as he said, if all peices are balanced individually, then the unit as a whole should be balanced when assembled. If you do not want to chance it, there are plenty of shops out there that can rebuild and balance a turbo assembly. You might have to ship it, but they are out there.

Unfortunately, I guess i'd have no way of knowing whether or not each component was balanced separately or together.

It seems like it'd be less of a hassle to just upgrade the entire turbo-but then I need to find a T3/T4 witht the exact specs that I want, namely the .48 a/r turbine, INTERNALLY wastegated, with the three hole-outlet for my downpipe--and I'd need to make sure the turbine side was identical physically to the one I have right now so as the downpipe would bolt up without an issue...Ideally I'd want a T3 turbine, .48 a/r, and a T04E compressor, .60 a/r with a 50 trim wheel, but I dont know where I'd find such a turbo for less than $500, but if I can get $300 for mine, which is almost brand new, then I'd be paying the same amount ($200) as I would for an upgraded compressor section as I would to upgrade the entire turbo...

[erich]

Check your local phone book for diesel turbo repair places. If you assemble it they should be able to balance it for you, or you could take all the parts there and let them do it.

[C-Kwik]

Well, you could call around to see who might be selling balanced components. But they'd have to be somewhat trustworthy. You also have the option of buying onlt eh center bearing section with the wheels you want attached. and the compressor housing you want. You should be able to reuse your turbine housing if you have a hard time finding the turbine with the A/R, discharge flange configuration and internal gate if you needed. As long as you get the same turbine wheel your turbo has that is. When you start to get specific about what turbo you want, you usually pay more. Unless you get lucky enough to find exactly what you are looking for.

[Structure240sx]

give ken at cheapturbo.com a call they have the best prices i've seen and do great work. my rebuilt turbo from them looked better than it did when it was new. i know they have upgrades for t-25's on their website but can get any compressor wheels. i know cuz i had to get a new one for mine.

[MarkEmark]

Just called cheap turbo-he said I'd be better off buying a whole new t3/t4, because for the cost of parts, etc, it'd be almost as much upgrading mine.

Damn--Guess that's my only route to go.

It's gonna be damn hard to find exactly what I want/need....(T3 with a .48 a/r turbine, INTERNALLY wastegated, 5 bolt outlet side that the internal wastegate cover will bolt up to, .60 a/r compressor, 50 trim....

Arrgh

Marc

[C-Kwik]

Well, you should be able to order it with the specs you want. You'll pay retail as opposed to ebay prices, but you will get what you want.