Gcg Xr6 Turbo Upgrade

[F6 UTE]

The 6boost exhaust manifolds are they a direct replacement and do they have a website?

Also I have the nizpro top half of the inlet manifold and just the stock lower half is there any proof that modifying the lower inlet manifold will work, I know simon milled his one out and it didn't do a thing. I can see how the exhaust manifold could make a big difference however.

If I knew this turbo upgrade wouldn't sacrifice much bottom end and mid range I'd order 1 tomorrow. I just don't want a laggy car and like the way I can fry the tyres at will when ever I like

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warning, this got a little off tangent, but oh well...

You will need to modify the dump and probably the compressor pipe a little, but I doubt very much, but mod none the less..

There is no 'proof' that a modified lower half alone will be of much benefit, but when you look at the drag GTR's and Supras, they all run short plenum runners for top end, combined with big turbos. Sacrifices low-mid, but gains up top.

Nizpro are said to have dabbled in modifying the stock lower half, but results were not measurable.. I'm unsure if they tried replacing the lower half completely though??

The GTR/Supra are King and Queen of 6 cyl development. Look at what's been done there, what's being used today and you get an idea of what works.

If you run a balanced combination, it will be a better 'package' all round. You have the built bottom end to support high boost/power, so use it.

As I was talking with Gramps today, it's all 2-5%ers.. Opinions are free. Knowledge is expensive. Where do you draw the line?? A good street package, a drag setup, or a dyno queen? Everyone wants different things from there cars, and in that base there opinions on it.

Why not bolt on twin GT28/xx's. Supporting ~450HP each, will spool on the 2Lt feeding it and be a good tractible combo with top end.. Comparible cost to $5.5k Nizpro setup, and will stand out like dogs nutss. Although, seems everyone with twins bolts on a big single..

All is well and good, but sit back and look at the big picture. Nizpro are building alot of the high HP cars, they have done the research. Even the 'other' cars making big HP untill recently, run nizpro gear, or Nizpro components..

Yes, APS make good hardware, there cars put out good numbers, guys use there exhaust, and intercoolers, mixed with Nizpro gear for excellent results..

The Nitto plenum is new, and based around GTR/Supra plenums. Though these cars run upwards of 7,ooorpm, so I'm unsure as to how the combination will work with a torquey 4L?? Should be good for power applications.

I suppose what I'm getting at is, everyone, regardless of plenum design, Intercooler used or injectors stuck in the head, results are very similar. So what does that tell you..Time to start doing something different, or maybe that's been done, and it didn't work.. I dunno.

I aint an expert on anything mechanical, but I do alot of 'looking' at what everyone else does, ( not just in aus ) I talk to alot of people to see what's needed and form my opinions on that..

Personally, I would have on my car, top 1/2 of intake manifold of unknown description, ( ie, I don't think one is much better than another ) A bigger, efficient cooler and an exhaust manifold.. Everyone does plenum, turbos, cooler, exhaust etc, but forgets the exhaust mani, until they replace the turbo and have to change it.. .. That would provide me with what I want out of the car. Massive midrange, while retaining good usable hp.

But that's me, and I'm not into getting airborne over bridges and engulfing small children into my exhaust, but it's fun watching other people do it..

Go bigger.................... go much bigger.......................................

[xlnt6]

My turbo upgrade is basically using the same configuration as the GCG turbo, ie 66mm wheel, 0.7 AR comp cover, ported and profiled wastegate. I also have done some porting on the stock manifold to improve port flow matching.

So far the car makes about 440 rwkW. M6 XR6T is correct, that the existing GT3540 turbo is very well matched (comp wheel vs turbine wheel and housing sizes). Therefore bumping up the flow capability on the comp side only means it pushes the turbine side into the edge of it's performance envelope. ie the turbine side runs out of flow. Given you can't buy a larger turbine AR housing size, the gain is capped by the fact you run out of flow on the turbine side.

You can work around some of those issues by reducing backpressure in the manifold (ie like I have already done), and post turbine side (ie. freer flowing exhaust). This is why the next logical setup, like the Nizpro setup addresses these issues. ie. a larger turbine wheel and different manifold, to get the flow capability up on the turbine side as well as the compressor side.

What I have noticed, it that the new wheel is more efficient as the car can support more advance in timing (due to reduction in compressor outlet temp), and it seems to me that there is no appreciable reduction in low down response. The OEM turbo comes on extremely hard in the mid range when you boost it to around 18 PSI. With the upgrade the power is more linear, which means it's much more predictable and streetable. Before the upgrade I made about 400 rwkW but the car use to absolutely fry the tires and wouldn't get any grip. Now, the power comes on like you been run up the ars* by a runaway primemover and the car just hunches down and takes off. So the end result is it's much faster.

I don't think getting much more than 450 rwkW on pump fuel with this upgrade is going to be possible. The flow capability is about 10% up from stock. Given the factory turbo is good for 400 rwkW then 450 rwkW is about the max you could achieve.

Like I said earlier the turbine side is where things start to go off the rails with this upgrade. Associated with this is a difficulty in controlling the wastegate and associated boost properly when turbine side backpressure starts to skyrocket.

Here is the post I detailed some of the work on the turbo upgrade including the port matching of the OEM manifold which you might find useful.

http://www.fordxr6turbo.com/forum/index.ph...topic=26190&hl=

Cheers

Robin.

[F6 UTE]

Thanks Robin. I read your thread, very informative.

Questions: Did the turbo upgrade quench your power thirst, or are you still left wanting?

: Why haven't you fitted an exhaust manifold- aftermarket?

This might help Youngy, Rapid and others in there decision making..

Cheers.

[Xtreme F6]

I believe the exhaust manifold is a huge must... Hence why im going to fit one.

[Goldbullet]

Stock turbo maxed out around 420 rwkw

[F6 UTE]

Stock turbo maxed out around 420 rwkw 

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What kind of boost was that at, + which manifold are you running?? custom jobbie??

[F6 UTE]

I believe the exhaust manifold is a huge must... Hence why im going to fit one. 

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Could you bolt the stock turbo to it and do a comparo for us?

[xlnt6]

Thanks Robin. I read your thread, very informative.

Questions: Did the turbo upgrade quench your power thirst, or are you still left wanting?

: Why haven't you fitted an exhaust manifold- aftermarket?

This might help Youngy, Rapid and others in there decision making..

I'm happy at the moment, but I like to play so maybe further down the track I'd like to try a few things. I'm comfortable making exhaust manifolds as I have done it before and I think there would be merit in a twin GT30 set-up, or maybe even using twin GT3540s but with smaller AR turbine housings.

The reasons I haven't changed manifolds were:

1. The upgraded turbo is limited by the turbine wheel size, especially when an oversized compressor is fitted. Hence the benefits of an aftermarket manifold in this configuration are reduced.

2. There isn't enough space between the turbo flange and the exhaust flange on the head to make a worthwhile manifold design, IF you retain the stock turbo location. ie you want to use the existing exhaust.

3. To make it worthwhile you need to rotate the turbine housing thru at least 90 degrees to make room for the runners of the manifold, then the exhaust has to be remanufactured to suit.

Therefore if you plan to use a stock turbo or this type of upgraded stock turbo the associated pain of making a manifold and having it all fitted (ie rework exhaust), is probably negated by the turbo itself.

Now if you intent to do a complete turbo upgrade to a GT40 or GT42 series, the turbine housing is split pulse T4 flange (vs OEM single entry T3 flange), external wastegated and has a V-band clamp or bolt flange outlet. All of which means it is necessary to produce a new manifold and exhaust hook-up anyway.

Now if someone HAS gone to all the trouble to do so, and has some empircial data to support it, then please do so, I am more than happy to be proven wrong !!

Cheers

Robin.

I believe the exhaust manifold is a huge must... Hence why im going to fit one.

Your going bigger series turbo though arent you ???

[Xtreme F6]

yes mate bigger turbo aswell

[F6 UTE]

Here is a pik of the 6boost type manifold.

Fairly simple, but as you mention robin reworking of pipework needed. It might even provide a better path that the factory location.

When you say the factory wheel is the limming factor, would the manifold change result in substancial low- mid range improvement?

At the end of the day, the total cost would be comparible to the CGC upgrade, but the results would be different. Worthwhile, well it should be and will be needed if a new turbo is used anyway..

I understand the stock wheel combination will flow as much as it will, and this won't change much, but I'm thinking it will aid in better spool.

As for twin GT35/40's. The tuner that hooked up my Xede and did my exhaust has 2 of these bolted to a manifold hanging off a 2JZ, no gates, no BOV, in an LJ torrie.