Potentially stupid question about turbochargers

shoes

shoes

shoes

Soldato
Joined
27 Jul 2011
Posts
3,534
Location
Staffordshire
I'm in the research phase of a turbo project for my little mx5 and I am absolutely bewildered by the range of turbocharger units available.

I rather suspect that the answer is no due to the A/R ratios and the design rotational speeds of the turbochargers, but would a turbo from a diesel engine be suitable for turbocharging a petrol engine?

Logic would suggest that turbochargers for diesel cars would be designed to peak with low levels of exhaust input compared to high revving petrol engine turbos, however after doing some googling I am most confused as there are so many conflicting stories.

Having failed to find a build log involving a diesel turbo I think I can probably answer my own question, however I thought I might be prudent to call on the wealth of knowledge shared by our resident petrol heads.

The reason I am asking a all is that diesel engine turbochargers are ten a penny and I'm doing this build on a budget.
 
"Turbo build" and "Budget" don't go well together. You'll skimp on something you really shouldn't and then bang goes the engine.

Seen it many a time on cheaply Turbo'd Fiesta ST's
 
Nasty things really, block up one end to get more air in the other, selection is balancing the 2 basically,

Why don't you think outside the box, switchable mechanically driven device combined with a free ram air type system ?
 
Best thing you can do is look for kits specifically designed for your engine model, many aftermarket companies will have a number of options available, alternatively you could try approaching a turbo specialists garage etc.

In theory a turbo is a turbo, but yes, some for diesels engines would be designed to run at lower rpm but higher temperatures.

Best advice is seek professional guidance, if you go to any garage the mechanics will normally be more than happy to advise
 
Pro advice seems like it may be worthwhile then.

Currently I am looking at TD04L and TD05 turbos, both seem in budget.

I'm trying to get the build done for under a grand with some more aside for a tune up by someone who knows their onions. I think it can be done, some parts are expensive - turbo/manifold/management but other parts are cheap - intercooler off a 90's Saab, used supra injectors, pipework, wiring.

I'm not buying anything until I have a shopping list approved by someone in the know.

I think I'll simply discount diesel turbos and continue the hunt for a decent TDxx charger or equal.
 
Often discussed on my car building forum, but I can't recall ever tried. You can find them of roughly suitable geometry for the intended application, but the usual reason against it cited is petrol engine exhaust temps are much higher than diesel so the turbines are simply not made of suitable material.
 
Do you know what power you are aiming for? It can be done DIY but you have to be sensible.
I wouldn't use a turbo from a diesel, i would look for a turbo that you can find on a standard petrol car, maybe something like a T28, you can get these pretty cheap.

What are your plans on a manifold? Intercooler? Fueling?
 
I'm not sure yet, I'll probably do the install myself but when it comes to mapping and tuning that'll be done by a professional for sure.
 
MartynB85 said:
Do you know what power you are aiming for? It can be done DIY but you have to be sensible.
I wouldn't use a turbo from a diesel, i would look for a turbo that you can find on a standard petrol car, maybe something like a T28, you can get these pretty cheap.

What are your plans on a manifold? Intercooler? Fueling?
Click to expand...

I'm looking for around 200bhp - 220bhp, nothing too serious.

This is as much an education experience for me as anything else, I have a long term plan of turbocharging my BMW but would rather learn the basics on engines which can be replaced for a hundred quid and very easily rather than the BMW engine.

For fuelling I am on the lookout for some 320cc injectors, apparently supra ones are good for this application.

I've been advised that at this power any old intercooler (within reason) will do the job. I know someone who runs an exhaust shop, he's going to be putting a manifold together for me, he made his own manifold for his own mx5 turbo build.

I'm looking at megasquirt management systems at the moment, although there are plenty of others I'm looking at and finding out the pros and cons etc.

Thankfully there is no shortage of mx5 turbo build logs to help me out :)
 
Depending on where you live, I'd recommend talking to Phil @ performance 5. He's pretty much the guru when it comes to tweaking MX5s.

Personally unless you're willing to spend a few k on it, I wouldn't bother doing it "on the cheap".

I spent about 3.5k turbocharging my Mx5 - that was for parts (FMIC, turbo, ECU, and pipework) as well as getting the ecu programmed.
 
Freefaller said:
Depending on where you live, I'd recommend talking to Phil @ performance 5. He's pretty much the guru when it comes to tweaking MX5s.

Personally unless you're willing to spend a few k on it, I wouldn't bother doing it "on the cheap".

I spent about 3.5k turbocharging my Mx5 - that was for parts (FMIC, turbo, ECU, and pipework) as well as getting the ecu programmed.
Click to expand...

Well this is a bargain then...

http://www.mx5parts.co.uk/sebring-supercharger-mazda-p-337.html

Turbos are for Diesels and they do a fantastic job, go drive a supercharged car something like an XJR or old Bmw Cooper s mini, instant torque is where it's at for a road car ;)
 
I'm also in the same bracket as the OP, looking into doing a turbo Mx-5 as a bit of a fun project and planning to do anything I can myself. This is much because I really like working on cars rather than because it might be cheaper although I won't complain if it is.

Freefaller, did you have someone do it or is the 3.5k a cost in parts and stuff you can't do on your own?

Edit, clearly I didn't read your post lol
 
Last edited:
Ðudeth said:
In theory a turbo is a turbo, but yes, some for diesels engines would be designed to run at lower rpm but higher temperatures.
Click to expand...

Diesels run a lower EGT than petrol, generally.

I've seen GT15/17s lifted from diesel engines and bolted onto 1.1 - 1.4 FIAT petrol engines, and not seen any cases where the higher EGT has been a problem.

Back to basics though, despite there being many different turbos around - the MX5 has turbo charging thing has been done a lot; learn from what other people did/used. You're not breaking new ground here, so don't laden yourself with the risks that would come with doing so.
 
Freefaller said:
Depending on where you live, I'd recommend talking to Phil @ performance 5. He's pretty much the guru when it comes to tweaking MX5s.

Personally unless you're willing to spend a few k on it, I wouldn't bother doing it "on the cheap".

I spent about 3.5k turbocharging my Mx5 - that was for parts (FMIC, turbo, ECU, and pipework) as well as getting the ecu programmed.
Click to expand...

I'm not willing to spend a few K on it, I'd rather use this to learn the basics and then spend the few K making my BMW go like stink instead.

I'm hoping not to blow it up but if it does it's no big deal really.

JAKUS said:
Well this is a bargain then...

http://www.mx5parts.co.uk/sebring-supercharger-mazda-p-337.html

Turbos are for Diesels and they do a fantastic job, go drive a supercharged car something like an XJR or old Bmw Cooper s mini, instant torque is where it's at for a road car ;)
Click to expand...

I have looked at the supercharging route but for some reason I really fancy a turbo setup to play with.

That doesn't seem to be a bargain either, an Eaton M45 will give the same output for a quarter of the cost :p
 
iaind said:
Is supercharging not much more common on MX5s?
Click to expand...

Looking at build threads I'd say about 50/50. Being a turbocharged engine originally it accepts turbocharging happily to a degree, and bolting an M45 on seems relatively easy too so it's quite popular.
 
You must log in or register to reply here.
Back
Top Bottom