TeamCapri

Tech, Repairs, Upgrades => Capri XR-2 89-94 => Topic started by: Rocketman on September 24, 2013, 12:20:33 PM

Title: A Treatise on Turbo Upgrades
Post by: Rocketman on September 24, 2013, 12:20:33 PM
Okay. Let's talk turbo upgrades here. Some of us XR2 owners would like more power, and have heard terms like "hybrid" turbos thrown around. This post will assume you know the basic parts that make up the turbocharger itself.

Our stock turbo is an IHI "VJ14". IHI is the manufacturer. RHB5 is the series of the turbo. VJ14 is the model designation. THE NUMBER HAS NOTHING TO DO WITH THE TURBO SIZE.

IHI was pretty kind to us, and made their turbo units somewhat modular. This means that we can interchange components from other RHB5 series turbos.

So once you've pushed your VJ14 to its limits and you want more, here's what we have available:
VJ14/VJ11 hybrid
VJ11/TBird hybrid
There are VF hybrids (VJ is Mazda, VF is Subaru designations) that are out there, but I am not too familiar with these.

With any upgrade, (beneficial for the stock turbo as well) it is necessary to port the wastegate! Failing to do so will result is major boost creep & overboost issues.


The VJ14/VJ11 Hybrid
This upgrade will flow enough air to break the 200whp mark. This turbo should not be pushed past 16psi!
The VJ11 turbocharger is found on the F2T engine in the states here, which was put in the first gen Ford Probe GT, Mazda MX6 GT & 626 GT. There are several differences with this turbo the main thing being the Compressor flows more air (cfm) which will equate to more power. For this upgrade, at the minimum you will need the compressor wheel and compressor housing. It's not a bad idea to obtain the whole turbo unit though.

The basic premise of the 14/11 is that you swap the compressor wheel & housing with the VJ14's units, retaining the stock mounting & fluid lines making for an easy to install low-impact upgrade. The mechanics of the swap itself are a little more complicated should you attempt this yourself. (the nut retaining the compressor wheel is reverse threaded!!!) It's highly recommended that a professional turbo shop swap the components & balance the rotating assembly. You may want to have the turbo rebuilt at the same time. The major thing to note with this method is the wastegate actuator bracket will need to be re-drilled, as the VJ11's compressor housing has slightly different bolt locations.

There's another method that does not require dis-assembly (& thus needing re-balancing) of the CHRA (center housing) but it is more overall work to install. You will need a whole VJ11 turbo in good shape! For those on a budget this may be the option for you, as rebuild/balancing can be quite pricey. For this method we will take the entire VJ11 assembly, and take off the iron turbine housing. The turbine wheels are the same. Fit the VJ14's turbine housing to the center section - you've now made essentially the same upgrade as above. The VJ11 has different coolant routing, and you'll need to test fit the turbo and adjust the placement/clocking of these fittings as needed. Again you will need to re-drill the VJ14's wastegate actuator to fit. Use transmission cooler or similarly rated line to route new coolant lines, being sure not to kink them as the fitment is not like the stock soft lines.

The VJ11/Tbird
This upgrade uses turbocharger parts from a 1987/88 Ford Thunderbird TurboCoupe. It *HAS* to be these years, it is an IHI unit. The earlier years used a much larger Garrett turbo which is not at all compatible with the IHI units. This hybrid is more of an "extreme" upgrade it's a little laggy but the power comes on real hard and stays.

The VJ11/Tbird uses the VJ11 turbine housing, with the Tbird compressor wheel. You can use either CHRA, it is easier to use a good Tbird and stick it into the VJ11 so you don't have to have it balanced. The compressor housing will need an adapter to connect your intake piping, and the coolant lines will need re-fitting.

The VJ11 turbine housing has a larger A/R and is capable of providing much more flow at higher power levels. The VJ14 turbine housing would choke flow and could potentially cause crazy overboost issues with this combo. This comes at the cost of some spool time, but the top-end benefits are worth the tradeoff.

The 11/Tbird hybrid should be capable of 250-275+whp @18-20psi.


Upgrade the 11/Tbird
There is an upgrade for the Tbird turbo called the "16T" upgrade. These were available from a seller on eBay - it is a Mitsubishi 16T compressor wheel reamed out to fit the Tbird, along with a re-profiled compressor housing. The CHRA also needs some modifications to fit the compressor wheel. Performing this upgrade brings the flow from 384cfm to 425cfm.


Title: Re: A Treatise on Turbo Upgrades
Post by: Jim Simms on January 03, 2014, 03:05:31 AM
The more I read your educational material, it is appreciated even more. The temptation to pump up my 91 XR2 is becoming more than an afterthought. Thank you for your educational and instructional posts.
Title: Re: A Treatise on Turbo Upgrades
Post by: Rocketman on January 09, 2014, 08:42:57 AM
I am glad this material is helpfu to you. Thank you!

Modifying the Capri is quite a lot of fun and very rewarding.
Title: Re: A Treatise on Turbo Upgrades
Post by: Jim Simms on April 28, 2014, 01:52:41 AM
I am so close to doing the hybrid, and hear different prices for rebuilts. You have been great with your recommendations.

If I send my VJ14 unit for a rebuild, and want the shop to do a VJ11/VJ14 hybrid, will I only have to supply the VJ11 compressor housing and the VJ11 compressor wheel ?

Will the compressor wheel fit onto the center unit, directly onto the same shaft?

I learned about porting out the wastegate, which you had suggested, on a you tube video.

Is it of much advantage to port the wastegate on a regular VJ14 rebuild?
What about installing the boost control on a regular VJ14 rebuild?

I know I dropped a couple questions on you.  Thank you for all the help.
Title: Re: A Treatise on Turbo Upgrades
Post by: Rocketman on April 28, 2014, 05:04:38 PM
You supply JUST the VJ11 compressor wheel, and compressor housing, along with your stock turbo.

Anytime you have access to the wastegate, it should be ported, stock or not. It will be of benefit in the long run if you do an exhaust upgrade or other work.

Boost controller on a stock VJ14 is fine, but not for the scope of this thread.
Title: Re: A Treatise on Turbo Upgrades
Post by: Jim Simms on April 28, 2014, 05:27:54 PM
Thanks for the info.
This site sure helps when talking to locals.
I found a turbo mechanic in Costa Mesa. CA, and the Team Capri info helps a lot.
Title: Re: A Treatise on Turbo Upgrades
Post by: xan175 on February 17, 2016, 09:52:24 PM
So i'm just kind of curious why you wouldn't just bolt on the T-bird turbo? or the VJ11 without making a hybrid?
Title: Re: A Treatise on Turbo Upgrades
Post by: Rocketman on March 06, 2016, 11:40:39 PM
So i'm just kind of curious why you wouldn't just bolt on the T-bird turbo? or the VJ11 without making a hybrid?

The Tbird turbo uses a T3 flange, and will not bolt to the Capri manifold. The VJ11 and VJ14 are the only bolt-on turbos.
You can use the full VJ11. The turbine housing is optimized for a larger engine and will thus spool slower.
Title: Re: A Treatise on Turbo Upgrades
Post by: Ed Hunter on July 15, 2016, 03:35:15 PM
Hello rocket, i found on the MX6 forum that compared the VJ11 vs a VJ5 which showed they are basically the same turbo (I guess the coolant inlet out let bosses are in a different spot which is not a big deal for this hybrid style). I was curious because i had access to a good used VJ5, So i grabbed it. Well i created the hybrid with my VJ14 and VJ5, drilled out the waste gate hole, bolted it on for testing purposes and it worked great. I have (and had) a small oil leak from my VJ14 so i'm going to get it professionally rebuilt and balanced like you suggest. Just thought i'd let you know it's another option. Thanks for this super helpful post.
-Charles
Title: Re: A Treatise on Turbo Upgrades
Post by: Gaz on September 18, 2016, 10:54:24 AM
Delete this, I got my answer.
Title: Re: A Treatise on Turbo Upgrades
Post by: Gaz on September 23, 2016, 11:14:20 AM
Okay, looks like I found a Vj11 with Upgraded comp housing using ht12 wheel and tbird housing for $200 plus shipping. Should I do it? I've got no info on the HT12 wheel benefits.
Title: Re: A Treatise on Turbo Upgrades
Post by: Gaz on October 23, 2016, 03:13:46 PM
Well, I went ahead and did it. What fittings will I need to adapt to that chra, if any?
Title: Re: A Treatise on Turbo Upgrades
Post by: Gaz on November 01, 2016, 04:49:44 PM
So, I got it in the mail, and it has cracks all over the wastegate port, one of which runs fairly deep along the inside tract of the turbine housing. I don't want to run it like this, but in the unlikely event I can't hot weld it, would it become a safety concern if I ran it as is?
Title: Re: A Treatise on Turbo Upgrades
Post by: Rocketman on November 02, 2016, 10:36:21 PM
Similar to the chronically cracked XR2 manifold, most VJ11 seem to have a crack on the WG.

Mine did, ran fine for me. It's not a safety issue - it may leak but it'd cost you spool time, rather than overboosting.
Title: Re: A Treatise on Turbo Upgrades
Post by: Gaz on December 13, 2016, 06:50:28 PM
Is this ht12 wheel comparable to a 16t wheel, you think?
Title: Re: A Treatise on Turbo Upgrades
Post by: azgtx on December 13, 2016, 08:39:36 PM
If you weld that housing and in the event a piece sluffs off while running, expect some noise. Best to keep looking for a good housing..call some turbo shops and see if they can order or have on the shelf in some dusty old back room a new one. Those were on a good amount of cars here. Otherwise try a VJ20 turbine, much less likely to be cracked. You will need to fiddle with the mounting flange but it uses the same elbow pattern from the VJ14. The VJ20 will afford you a better spool up than the VJ11 anyway.
Title: Re: A Treatise on Turbo Upgrades
Post by: Gaz on December 14, 2016, 02:30:46 AM
According to the original post, I could take my vj11, and just throw the V-J 14 hot side on to it? Hell, if that works, I don't have to play with a cracked housing.

Note that my setup is, from turbine to compressor, vj11 turbine and chra, tbird comp housing, ht12 wheel. Can I just unbolt the vj11 turbine housing and bolt on the vj14 turbine housing?
Title: Re: A Treatise on Turbo Upgrades
Post by: azgtx on December 14, 2016, 06:38:43 PM
yes you can but that tbird needs more turbine housing than the R12 from the VJ14 can give. No real sense in that. Look for a vj20 housing and fiddle with the flange to fit the B6t manifold and then you will be better off..or look for a good vj11.
Title: Re: A Treatise on Turbo Upgrades
Post by: Gaz on December 15, 2016, 12:08:27 AM
My turbo guy couldn't find one, or so he says. Anyone have a good turbine housing for sale?
Title: Re: A Treatise on Turbo Upgrades
Post by: WashiestSnake on December 15, 2016, 03:16:25 PM
Gaz why not run a different turbo then the IHI stuff.  For less then 800$ you can get a turbo, dump, and manifold that flows quicker and more air then the IHI stuff can.
Title: Re: A Treatise on Turbo Upgrades
Post by: Gaz on December 15, 2016, 04:56:52 PM
Wouldn't fit the stock ish budget mod mentality I'm rocking for now. I'll probably be selling this car when it's done, anyway.
Title: Re: A Treatise on Turbo Upgrades
Post by: Gaz on January 19, 2017, 01:16:00 AM
Gaz why not run a different turbo then the IHI stuff.  For less then 800$ you can get a turbo, dump, and manifold that flows quicker and more air then the IHI stuff can.

Just for giggles, can you entice me with a link on a recommendation?
Title: Re: A Treatise on Turbo Upgrades
Post by: ShelbyZ on January 19, 2017, 10:51:39 AM
There's another option:

http://www.ebay.com/itm/IHI-VJ14-to-T3-Turbo-Inlet-CNC-1-2-Transition-Adapter-Mazda-Mercury-Capri-T3-T4-/141938458367

http://www.ebay.com/itm/IHI-VJ14-to-T25-Countersunk-Turbo-Inlet-Adapter-Mazda-Mercury-Capri-T28-GT2860RS-/131896128352

Those will allow you to bolt a T25 or T3 flanged turbo to the stock manifold.
Title: Re: A Treatise on Turbo Upgrades
Post by: DarkAngel on January 19, 2017, 11:54:18 AM
I'm curious :)

What type of T3 / T28 / other turbo system do you guys use... ECU ?... Wastegate ?... Intercooler size ?... exhaust size ?... Turbo Electronics ?...  etc
Title: Re: A Treatise on Turbo Upgrades
Post by: greywolf27030 on January 19, 2017, 01:03:55 PM
Interesting.....

Jack Byrd
Title: Re: A Treatise on Turbo Upgrades
Post by: WashiestSnake on January 19, 2017, 02:31:54 PM
The Garret GT2560 is a ball-bearing turbo that came on the Nissan 240sx and Silvia, this means alot of people sell them for cheap when they upgrade. If youre lucky you can get one for 350$, the rebuild kit is 120$ of ebay. You can get good quality aluminium t3 manifolds of the Mazda 323 GTX Facebook group for around 250$, you could reuse the stock blow off, or upgrade to a electronic system.  GFB makes a good boost controller you can get for around 150 used or 250 new. For the dump pipe Id have a turbo shop make it for me I wouldn't expect it to be over 280$.
If you got a non electric blow off you could save alot more, but as it stand it would be 1150$ for just the Turbo, dump, and boost controller. You'd still need the fittings for the oil drain,piping and a larger intercooler. That turbo however can give you up to 300hp on a good tune.  You could probably get everything for alot cheaper if you were good at scavenging things from the junkyard, and searching ebay really hard. In the coming months ill be starting my turbo build. I plan on detailing everything on my build thread.
Title: Re: A Treatise on Turbo Upgrades
Post by: chrispoe on January 23, 2017, 10:22:28 AM
Ssounds like you've got your turbo build pretty much figured out WashiestSnake.
If you're going for 300hp, you should also get some 500+cc  fuel injectors and a new ecu to control em.
Title: Re: A Treatise on Turbo Upgrades
Post by: WashiestSnake on January 23, 2017, 03:05:17 PM
Yea everythings planned for the only problem is im stuck with the shitty F-series, my cars a N/A. I cant seem to find a Escort GT either to scavenge the transmission from I might end up having to get one of ebay or just run real low boost until I can get the GTX stuff put in.

Another problem I have is that ill be moving soon, and going back into School in May so that may mean ill have to hold off for longer. Im honestly thinking about just keeping my b6 and turboing that, BPs are rare as hell down here. That would help me save alot of time on the AWD swap aswell, as im horrible with wiring thats the main reason I was planning on using the Evo ecu.
Title: Re: A Treatise on Turbo Upgrades
Post by: Gaz on March 12, 2017, 12:45:48 PM
I'm incredibly interested on the evo ecu bit. What's that about?
Title: Re: A Treatise on Turbo Upgrades
Post by: WashiestSnake on March 12, 2017, 02:09:48 PM
Basically its a reflashed Evo8 ecu meant to run a BP. It includes a wiring harness, and depending on if you buy it or not you can get a C.O.P kit to go along with it. Its made by BP Performace on Facebook and a few GTX guys on ClubProtege have switched over. It requires a Map sensor and a Cas sensor from a Miata. Ive talked to him about using it for a b6 and he said it was possible but not very easy. He said he had a hard time getting a b6 Miata to run right. Basically its way cheaper then Megasquirt and you get the ability to download tunes straight through a connector on the ecu rather then having to use a laptop like Megasquirt. It also should have much more reliabilty.

My plan is to buy a BPT, get it installed then install his Ecu setup. I eventually might get a BP4W head aswell because he takes Evo manifolds and reflanges them for BPs so that would take allof the hardwork out of using the BP4W. Also it uses stock connectors so you could always install a PnP MS3 to run the vvt.
Title: Re: A Treatise on Turbo Upgrades
Post by: greywolf27030 on March 13, 2017, 07:37:09 PM
BP Performance posted today a dyno chart on a 92 Miata B6 with a Chinese turbo kit.  The car has 180K and no other modifications, they got 216hp and 202tq on chassis dyno with 11-12 psi of boost.  They show a chart on their FB page. It shows like 200hp all the way to 7K.


Jack Byrd
Title: Re: A Treatise on Turbo Upgrades
Post by: rls120 on July 13, 2018, 09:45:16 PM
Thanks!

Non interference is great news.   I don't mind if it leaves me walking, but I didn't want to destroy it.
Title: Re: A Treatise on Turbo Upgrades
Post by: Skunkwrkz on October 30, 2018, 01:29:27 PM
Ok, So who's competent nowadays in marrying the The VJ11/Tbird hybrid? Back when I was tuning MKI MX6GT's, there was a user SixSick6 I think, that worked at a turbo shop in Cali and sold these.
Title: Re: A Treatise on Turbo Upgrades
Post by: Rocketman on October 30, 2018, 10:43:16 PM
SixSick6
Now there is a name I haven't heard in years!

No idea on any current turbo rebuilders.

On my turbos I have used the whole CHRA and adapted the oil & coolant fittings, as opposed to breaking them apart to hybridize them, so as not to disturb the balance
The 16T upgraded 11/tbird I put together without balancing and had some issues with it, I'm unsure of the cause though, could have been a bad CHRA to begin with.

Title: Re: A Treatise on Turbo Upgrades
Post by: Skunkwrkz on November 01, 2018, 12:30:31 PM
Even further back than that, I was on the MX6 yahoo group before MX6.com. There was a guy who was a tuner in Orlando that first told me about the VJ11/Tbird. Supposedly, this hybrid is the same trim and specs as the Ferrari F40 right side IHI turbo. Just thought that was a cool thing to note that some may not be aware of.
Title: Re: A Treatise on Turbo Upgrades
Post by: GT40 kook on July 04, 2019, 10:17:23 AM
Can anyone here tell me other makes and model of cars, maybe Subaru, that have used the VJ14?  I'm having a time finding a rebuildable turbo for my friend's low budget festiva project.  Found an old festiva with a 323 turbo engine in it and when I tore the turbo down for rebuild found it was beyond help. 
Title: Re: A Treatise on Turbo Upgrades
Post by: Rocketman on July 04, 2019, 03:10:37 PM
The Capri and turbo 323 were the only cars that came with the VJ14. Your best bet is upgrading to the VJ11 hybrid (using the VJ11 core) those were used on the older Ford Probe GT and MX-6 GT with the 2.2L F2T engine. The VJ11 is the only other turbo that will mate to the stock manifold and the info on that is covered in the first post of this thread. Nothing else will bolt up, you will have to go custom with either adapters or a new manifold otherwise.

There's a UK seller selling brand new VJ11 CHRA assemblies on eBay for a reasonable price: www.ebay.com/itm/321141509784
You would still need the compressor housing and some other bits but it's a solid start
Title: Re: A Treatise on Turbo Upgrades
Post by: Kiwimagic on June 20, 2020, 06:18:47 PM
Hi.
I have managed to pick up a VJ11 CHRA and compressor housing so will be going down these lines.
 There's another method that does not require dis-assembly (& thus needing re-balancing) of the CHRA (center housing) but it is more overall work to install. You will need a whole VJ11 turbo in good shape! For those on a budget this may be the option for you, as rebuild/balancing can be quite pricey. For this method we will take the entire VJ11 assembly, and take off the iron turbine housing. The turbine wheels are the same. Fit the VJ14's turbine housing to the center section - you've now made essentially the same upgrade as above. The VJ11 has different coolant routing, and you'll need to test fit the turbo and adjust the placement/clocking of these fittings as needed. Again you will need to re-drill the VJ14's waste-gate actuator to fit. Use transmission cooler or similarly rated line to route new coolant lines, being sure not to kink them as the fitment is not like the stock soft lines.
My new units are still in the post so,
What is the mod required to the waste gate actuator. Is it the fixing bracket that needs drilling or the actual housing.
Title: Re: A Treatise on Turbo Upgrades
Post by: Aus Capri on May 19, 2021, 08:58:16 AM
Hi guys here's a little info on the Subaru VF turbos mentioned at the top of this post.

VF10 uses the same 9 blade turbine as the vj14 and is a bolt on upgrade. The inlet to the compressor is different though its not hard to make something to adapt it to the existing j pipe.

VF8 is larger than VF10 and uses a different bigger 10 blade turbine wheel that does not fit the vj14 rear housing. It can be made to fit by using your VJ14's turbine wheel or having your Vj14 rear housing machined to fit the Bigger VF8's turbine wheel.

VF12 bigger again than the VF8 and uses the same larger 10 blade turbine shaft. Can be made to work in the same way as the VF8 by using the Vj14 turbine wheel or machining your vj14 housing bigger.

They all have the same inlet to the compressor which is different to the vj14.

The water lines both enter the turbo on the same side like the Vj11 CHRA and that needs hooking up differently than the vj14 as well but its not hard to  make it work, I used one of the water banjo lines from a vj11 and one from a vj14

I have heard the VF12 with the larger turbine will make up to 260hp!

I dono their availability in the USA but can be found in England, Australia and Japan of course!

VF8 AND VF10 can be found on older single turbo legacy and libertys (early 90's) and the VF12 came on  the Liberty RS of the same era

They still pop up from time to time on Ebay so keep your eyes peeled...

May the boost be with you!