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Discussion Starter · #1 ·
Howz it goin?

I want to upgrade the turbo in my '91 to a larger unit so it is more efficient higher in the rev range, and doesn't run out of puff at higher boost. I'm looking for a turbo that will bolt straight onto the stock exhaust manifold.

Any ideas as to which turbo (IHI) best suits the 2.2's characteristics? Will the VF series bolt on in place of the VJ (i.e. WRX turbo)?

I'm hunting for mid 13s (eventually), with a complete 3in mandrel bent straight-thru system, stock 'cooler (with water spray) and upgraded intercooler plumbing.

Currently the car is dead stock except for a Centreforce clutch - preparing for an increase in power.

Thanx
 

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Dude!
How ya doing I don’t think I’ve come across you before are you a newby??....... COOL welcome.
About your turbo, there are some pretty cluey yanks on this board if you post this sort of question on the performance mods page you will get a really good response. That’s not to say us Aussies aren’t cluey but our numbers are limited...
PEACE
PK

:)
 

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Turbo Upgrades

While the American guys are quite cluey (some of them, others dribble rubbish) you will find some of their advice useless to you as the upgrades they talk about are all available in the US and not really so much here.

The are no direct bolt on upgrades for our cars here is Aus. You have two options.

1.) Hi-flow the existing unit. The standard turbs is a RHB5 with VJ11 compressor wheel. You can hi-flow this with VJ17 wheel or VJ23 wheel aswell. Pretty much anything what will fit in the compressor housing really. They can also do an cut back on the exhaust housing side aswell. Hi-flows are generally only good for small increases in power and aren't the most efficient way of getting more power. It is cheaper though...max power output with hi-flow work I would estimate 120-130kw ATW. When it comes down to it the standard turbos are too small for our engines to make good power. No way will you do a mid 13 this way.

2.) Any other turbo you like! This requires either an adapter plate on your exhaust manifold or a custom exhaust manifold(generally quite expensive)

This is the best way to get the most power out of your car. You can go for a T28, T03 or the expensive ball bearing turbos such as GT25, GT28, or IHI VF23, VF22 etc etc.

For mid 13's I'd estimate you'd want at least 160-170kw ATW. A T03 with good mods could do this, the ball bearing ones would easily...

Early WRX turbos would be a good choice. The TD05H will be perfect in its efficiency band on our motor at around 16-18 psi. ( I have compressor map) This should make around the power you want.

There will be other mods needed though...if you wanna chat in more depth either post here or send me a email

Pete
 

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Discussion Starter · #5 ·
Thanx for the advice PeterD.

I've since been told that GCG turbos will adapt the MX6 exhaust wheel & housing with an STI series IV compressor wheel and housing for $750. I haven't heard much about this place, do you know of anyone who has had work carried out by them? That red MX6 in Hot4s a while ago with the 18in Niche rims had this exact same mod, still ran the stock cooler with 3 inch exhaust and water/meth injection- the guy reckoned it pulled a 13.7.

Although if I do go ahead with the conversion, I might be better off with your suggestion of using an adapter plate and fitting the turbo of my choice; I work at a sheetmetal factory and can lasercut up to about 10mm mild steel ....

:cool:
 

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well there are some people that have a LOT of fun with Rx-7 Turbo. namely Anarchyx34 you should get intouch with him

just my little PLUG :D
 

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There was a MX6 wiith a T03 in Hot4s a couple of years ago. It pulled a 13.8 on 16psi with std intercooler and 7.8:1 forged pistons.

There was a gold 626 turbo at the Willowbank Jamboree a month ago that pulled a high 13 with what *looked* to be a standard turbo. Most probably been hi-flowed.

I'd go for the hi-flow option personally as I know my insurance company is reluctant to insure me as is (10psi std turbo) let alone a total turbo change.
 

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Discussion Starter · #8 ·
Spectral- I just wouldn't tell my insurance company. I reckon the average assessor probably wouldn't know if it had a stock turbo or an upgraded one (unless there was another MX6 parked along side it).

Pete- I've spotted a TD05H in the TP for $500neg. Is this a reasonable price if it is in condition? If I do check it out, what should I look for?

If I change the turbo I'll probably switch to programmable injection so I can bin the A/flow meter and get greater tuneability, I want to leave the internals of the engine alone so I'll probably limit boost to 16PSI. Do you reckon I could get away with just using a rising rate fuel pressure regulator? Bigger injectors would probably be better I suppose, but I want the most cost effective option (doesn't everybody?)

:cool:
 
G

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why the hell does everyone think that binning the airflow meter and replacing it with a throttle position sensor and a map sensor, will give greater tuner ability of the engine.
the airflow meter is by far the most accurate air measurement device. if it wasn't why would most japanese tuning shops opt for after market computers with a larger airflow meter capable of flowing the required amount of air for the particular engine.
the only sensible arguement for removing it is a restriction to the passage of air entering the turbo, and even this is incorrect - if you don't believe me, take one and put it on a flow bench. the numbers will surprise you. at the end of the day the AFM will provide the most accurate measurement of air entering the engine at any throttle, load or boost point.
 

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Discussion Starter · #10 ·
I'm just exploring my options at the moment, AusMX6. I haven't had much to do with MX6's until now, I'd just been told that the AFM does restrict the airflow to a certain degree, and I know this to be true with other cars so I didn't disagree.

So if the MX6 AFM doesn't really restrict the airflow, do you think a more effective way of tuning would be to play around with the voltages being read by the AFM (a la HKS F-CONV?)

The reason I was thinking full programmable injection is that they seem to be similarly priced to the piggy back units. I've been told the MX6 runs just as well if not better (i.e. idle, cold start, smoothness etc.) with an MTX-8 than with the stock computer.

But, like I said, this is only what I have been told. Think I'll just have to find out for myself ...

Anyone else have any other thoughts/experience on this topic?



:cool:
 

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I, like MXMAGIK, am relatively new to these cars, but in my old EXA turbo, the AFM was very error-prone with the spring tension (vane-type) giving problems and replacing it with a bigger/newer unit (ie. from the Isuzu Piazza) gave good improvements.

Not suggesting you are incorrect AusMX6, but would a MAP sensing setup give a very accurate measurement of fuel requirements???? Especially with BOVs venting to atmosphere etc..

Your thoughts??
 

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Ok,

First of all, I think that the 13.7 quoted by the guy with in Hot4S is very optimistic for the mods he had. It was also done on a G-Tech, not on a drag strip. With those mods I would expect a low 14.

Also the RX-7 Upgrade they talk about here is simply a hi-flow with a big compressor wheel. I think they use the S IV compressor wheel and machine the standard housing to fit it. This still doesn't address the issue of our exhaust housing side having a restrictive (for top end power) A/R ratio and subsequently reduced potential.

MXMAGIK,

$500 for a TD05H is around the going rate. If it's in good nick that could be a go-er. This is the turbo I am looking for in my car. You can either source one from a 93,94 WRX or VR4 motor aswell. As for condition you can check for shaft movement (there should be none) Try your best to find out how many K's its done, inspect the condition of the wheels and thats about it. For absolute reliability a rebuild would be best.

In my opinion a custom tuned chip would be the way to go for you. Chiptorque will do custom written chips and the MX6 ECU is quite advanced. A custom chip installed and tuned with dyno time should set you back between $800-$1000. You retain the good factory setting that you mentioned.


Spectral,

Can u give me more details of the MX6 with T03? I haven't seen that one...


Cheers guys
Pete



:cool:
 

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Discussion Starter · #13 ·
Pete - Yeah I forgot that was done on a GTECH, and its also just the owner's word (no timeslip on one of those .....)

I might go check out that TD05H. I'm putting the exhaust on soon, just trying to decide whether or not to do everything at once so I don't have to change the exhaust when I put a bigger turbo on.

I'll also enquire into the custom chip option (I admit I'd completely forgot about that).



:cool:
 

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PeterD: yeah no probs.. I'll scan the article and put it up on my website. I'll let you guys know when its done.
The car was a red 1989 (i think) MX6, number plates "LETHAL" in NSW.
 

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MXMAGIK,

Yeah, go check it out....if you don't want it PLEASE let me know!!!

Spectral,

Thanks heaps!! Let me know when you get it!

Pete
 

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Discussion Starter · #16 ·
PeterD- just an update on the TD05H.

Just rang the dude- it's off a '96 WRX and the turbo has done around 45K, always had a turbo timer and has been checked by a turbo specialist who said there was nothing wrong with it all. He's also including a dump pipe (with seperate pipe for the wastegate) and the gaskets.

I'm going to check it out tommorrow ....
 
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