Truth about turbo positioning
 

Hi everyone, I am long time lurker from London currently living in Australia who is after a new car and who finds the GT86/BRZ platform pretty tempting.

Lately I was doing some researches about forced induction because I currently own a turbo charged car (my first one) and I definitely love the way it drives compared to the other, previous, NA sports cars I had, so I'd like to go that path. While reading around I stumbled across this statement (which probably many of you read too):

“Going only on anecdotal evidence, it seems very much like there are far more supercharging options available in the UK for the GT86 than turbo kits. The reason? It’s all to do with where the steering wheel is.

On all GT86s and BRZs, the exhaust manifold exits to the left-hand side of the car. So, on left-hand drive vehicles, there’s a nice space for a turbo on the other side of the engine. On right-hand drive cars though, that space is taken up by the steering column. It is possible to mount a turbo further forward and lower down, but it’s not the best place for keeping a blower cool, Feasey tells us.

So, if your steering wheel’s on the right, you’re better off with a supercharger.”

My obvious question is, is that true? And even if it is true, is it an actual real deal breaker for this specific car (I am talking RHD) or an actual turbo conversion can be achieved with good reliability and performance output regardless? The reason why I am asking is because I am not a expert about forced induction and I never thought that in a turbo (being exhaust driven) the positioning was so important.

If anyone can elaborate on the topic for me it will be very much appreciated.

Thanks.

You do not need to worry about "keeping a blower cool". Most modern turbochargers, or "blowers" as you've called them, often a term reserved for superchargers, have the CHRA cooled with water. Turbo placement is much more critical when it comes to the air it will be ingesting. As far forward and clear of obstruction and heat sources as possible. The most efficient way to feed a single turbo is facing forward out the front of the car, with a velocity stack right on the inlet. This isn't the most feasible for a daily driven car mind you, as it means placing it in the grill, or removing a headlight, and becomes difficult to filter the incoming air from contamination and debris. More to my point, your steering rack has very little to do with the turbo itself, moreover, the exhaust manifold routing to spin the turbine.

Thanks @tokai444 for the explaination, that however means that for example (based on pictures) a Full Race or Full Blown kit will on average perform better than a AVO, becaue the former two are front mounted while the latter is just down under. Is such assumption correct?

I feel that I've been misquoted there.....

as I recall I actually said having the turbo so close to the engine can give heat related issues to the engine
I know of a few low mounted turbo installations that have issues with overheating wiring / VVT actuators, cooling fans etc

its has little to do with how the turbo actually performs, although airflow over the turbo is also nice to have as it will buy you a little headroom

Quite a few people run turbos in the UK. Fensport offer the AVO turbo, Tuning Developments also do a turbo kit which seems pretty decent value for money.

I'm biased (and I've not driven a turbo), but I think that if you are not after big numbers then you are better off with a positive displacement supercharger for the 86.

Most of the turbo kits I've seen for this car have the turbo mounted in front of the engine, not to the side. I don't see why that would need to be different for a RHD car, other than exhaust routing.

While those you mentioned are front mounted, they are not forward facing, and use intakes on the compressor inlet.

The only issue between LHD and RHD vehicles is when you rear mount the turbo down near the gear box. Ptuning offer a great kit for this location but do not offer a RHD version. However an Australian company in Victoria have released some photos of their kit which looks to be based off the ptuning kit and they have managed to clear the steering column

Thanks everyone for the replies and the support.

Hi Matt, thanks for rectifying. So basically we can just say that it doesn't matter too much given that good quality components are used (depending by availability in the country) and the tuner knows what he/she is doing?

Also do you at cossworth provide turbo conversion or only the supercharger kit?

I am biased too (and I've not driven a supercharged) that's why I'd like to stick with a turbo charger. Thanks for the advice, I will check them out.

Because of components displacement I guess. In a RHD it's not like the entire engine bay is swapped, only few parts, so available room for adding elements might differ.

True, but as Matt@Cosworth explained, in other areas overheating can be an issue so I suppose I am better off looking at front mounted solution where possible.

no we only provide a supercharger kit although we we are in the process of releasing a bottom end, oil baffle plate and a few other bits and bobs

Can I ask why? Genuine question out of curiosity...

I believe this could the rumored Stage 3.0 kit I've heard whispers of. Right now their Stage 2.0/2.3 is their Supercharger Kit. Stage 3 would be for more power without risking a blown engine... But Matt can tell you more.

I honestly do hope so mostly because they are local to me and they are a brand I remember from my childhood and that I respect heartedly and because I was looking into the Ptuning kit but it seems it's not coming in RHD version.

I believe they didn't offer a turbo due to heat issues, as well as wanting a more linear response. As well, I think the piping wouldn't fit for you right hand drive folks.