Garrett T25 or T28 on a GTX BF

[porschedriver]

Hi, I have been looking for an exhaust manifold for the BF GTX / B6 engine to fit a Garrett roller bearing charger for almost a year now, found none !! is there maybe a flange adapter instead? I see many on ebay, but I cant tell what flange the VJ9 or VJ14 have? some ebay sellers can custom make one, but they need the exact measurements, can someone help PLEEEEEEAAAAASE

thanks

[tweety2300]

The stock turbo flange is an rbh5. You can use a miata manifold but you will need a custom down pipe oil lines and water lines along with ic piping.

Also I think the cfm rating on the t28 is too high for the reich racing ecu to handle so you may want to look into megasquirt. The t25 heatsoaks it's self over 14 psi

I know my vj11 can hold 19-20 psi to 6500 rpms. I'm not sure why you would want or need anything past that without looking into fuel pump injectors tuning etc. and also making sure the internals can hold it

[porschedriver]

Hi, the available miata turbo manifolds show upwards which will make a mess in the engine bay.
I have a comletely overhauled engine with forged pistons, forged rods, ARP bolts and a JDM multilayer metal head gasket, a megasquirt, separate sparks, walbro etc.. and need a roller bearing turbo to overcome the turbo lag, but if the VJ11 is an option, I will consider it.

What will the VJ11 give me compared to the stock VJ14 or VJ9?

Still using stock injectors, which injectors can I use for upgrade (plug and play), I mean without cutting wires? any ebay seller?

cheers

[Rocketman]

The Vj11 only offers around 30 more hp than the stock VJ14. At 20psi the VJ11 is way past it's efficiency range and puts a lot of stress on the bearings, it won't last long. Shouldn't be run past 16psi. YMMV, I guess.

Porschedriver, there are a few manifold options out there but all quite expensive. There have been adapter plates but the turbos usually end up dangerously close to being too low to proper drain oil. I've seen someone mill off bits of the stock manifold & weld a new flange onto it with good success.

http://www.turbinetech.ca/en/products/mazda/323-gt/b6t-stock-turbo-manifold/120/view.html

Some people have used the Miata manifolds, but had the turbine flange modded and flipped for a bottom mount log-style manifold. It's an option

[jay]

If you don't want lag, I bet a 28 is too big for 1.6l. OTOH and gt25 may be a touch too small but I haven't run one to know. I'm using gt28 on teh rallycar and it builds 5psi as low as 1900RPM, but the intake and exhaust are both wide, wide open (no muffler AFM no stock parts there at all) and it's 1.8l. For the cheapest possible solution to the manifold problem, take a look at jgsturbo.com. Log mannies, in kit form, that should do the job. I have one that we used on the rallycar for a bit before we stuck a GTR manifold in there. It worked well enough I think.

[tweety2300]

Actually if you look enough there are bottom mount manifolds for the miata

As for 20 psi on the vj11 I just wanted to see what the reich racing ecu could handle. It leans out over 18 psi. I run 14-16 depending on weather

How do you build 5 psi at 1900 rpms? I build 7 at 3000 and 14 at 3500. It won't even build boost under 2000 rpms I have a 2.5" dp back with high flow cat and k&n filter on the vaf and the probe smic.Is that normal?

Not to thread jack just makes me wonder if I have a boost leak

[porschedriver]

Hi,

jgsturbo.com discontinued their kit and turbinetech.cais $695.00 which is a bit too dear.

I will try to cut the original flange, it will be a problem though welding sheet steel to cast iron, but I will try.

Anyone knows a plug and play injector replacement? are the BF injectors high or low impedance?

thanks

[porschedriver]

Actually if you look enough there are bottom mount manifolds for the miata

As for 20 psi on the vj11 I just wanted to see what the reich racing ecu could handle. It leans out over 18 psi. I run 14-16 depending on weather

How do you build 5 psi at 1900 rpms? I build 7 at 3000 and 14 at 3500. It won't even build boost under 2000 rpms I have a 2.5" dp back with high flow cat and k&n filter on the vaf and the probe smic.Is that normal?

Not to thread jack just makes me wonder if I have a boost leak

I have never seen a bottom mount one in years, did you ? can someone point me to a bottom mount miate turbo manifold?

thanks

[jay]

"How do you build 5 psi at 1900 rpms?" Built 1.8bpt @9.5;1, 3" short intake/big IC, no flappydoor VAF, 2.5" downpipe into 3" dump with a cat for a muffler and nothing else. So, rallycar. I only wish my streetcar made boost that low.

"It won't even build boost under 2000 rpms I have a 2.5" dp back with high flow cat and k&n filter on the vaf and the probe smic.Is that normal?" -- Yeah, pretty much.

[Rocketman]

Tweety - Ditch the probe SMIC and go to a real FMIC and larger piping, that reduced my spool time quite a bit. Get rid of the crap plastic turbo intake pipe, and go with something much freer flowing - open up the intake tract.

Are you running a full VJ11 (turbine housing too?) or a 14/11 hybrid? The VJ11 turbine will make an 11 spool like crap on a B6T but have great top end

[tweety2300]

I've been planing on doing an fmic but holidays are coming so it wOnt be for awhile. I do have the full vj11. And intake pipe is going just trying to find a way to match it with the inlet on the turbo and then match it on the vaf side seems to be the pita part

[Rocketman]

Pita? hardly. Here was my solution some 4 or 5 years ago now: http://www.werbatfik.com/img/capriwork/capriwork236.jpg
I also make a bolt-on Jpipe similar to the old HK$ piece http://www.werbatfik.com/uplimg/jpipe/jpipedisplay.jpg

Your #1 problem is the VJ11 turbine housing. The A/R is not well matched to the B6T. Either swap the turbine housing to a VJ14 (will drop your spool time drastically) or throw a larger compressor on the cold side (Tbird/VF11, etc) to compensate. With the 14's turbine housing you'll have plenty of usable boost by 2500 rpm and full boost by ~3000 or so, but you will lose a bit of top end power. But you'll have a much more usable powerband

[porschedriver]

Pita? hardly. Here was my solution some 4 or 5 years ago now: http://www.werbatfik.com/img/capriwork/capriwork236.jpg
I also make a bolt-on Jpipe similar to the old HK$ piece http://www.werbatfik.com/uplimg/jpipe/jpipedisplay.jpg

Your #1 problem is the VJ11 turbine housing. The A/R is not well matched to the B6T. Either swap the turbine housing to a VJ14 (will drop your spool time drastically) or throw a larger compressor on the cold side (Tbird/VF11, etc) to compensate. With the 14's turbine housing you'll have plenty of usable boost by 2500 rpm and full boost by ~3000 or so, but you will lose a bit of top end power. But you'll have a much more usable powerband

Hi Rocketman, what is really the advantage of the VJ11 over a VJ14?

cheers

[Turpro]

Vj11 is bigger

[azgtx]

Anything over 12psi on the vj14 is just blowing hot air...over it's efficiency. By mating the vj11 compressor to the vj14 allows 16-17psi all the way to redline while keeping the quicker spool. With the equipment you say you have I would look to the Garret 2860 to get the full benefit of the stand alone management.