Damocell

iTrader: (1)

I realise this has been asked alot but no one seems to really mention Owen Developments.

So what is the best turbo (from any company) to extract the maximum power without blowing the engine from a 2.5 STI with the standard pistons?

Also what do people know about Owen Developments and their range of turbo's

Damo

Tidgy

owen dev are a very very good company as i understand it, but not the cheapest, also they can build a turbo to your spec.

they developed the trubo on the fq400 evo by the way

Damocell

iTrader: (1)

Wasn't the FQ400 really quite laggy??? Not to compare turbos from different cars

Damo

preza si

this is a good question, i am about to undertake a 2.5 rebuild looking around for turbos to suit.

found this one from owen
Owen Developments - Online Catalogue

now is this the same as the md321t?

i am guessing they both use the same garrett ball bearing core with the modified subaru exhaust housing?

as this is now cheaper than the md321t from andy f which seems to have just gone up!

Lateral Performance

iTrader: (20)

I don't know what parts Owen use in their turbos, but based on the combination of parts we use, and the consistant results we get, I would never rate the "T" as a 475bhp + turbo, and the Owen exhaust housings are very different to the ones used on the MD321 series.


With regard to pricing, the MD321 series have had a price increase due to Garrett having a price increase, and also the state of the Euro, because official UK Garrett dealers have to buy from Garrett Europe, in Euros.


The prices went up a few months ago, but Mr Forrests IT skills are a little slower than his mapping skills


Mark.

MartynJ

Mapped one on a 2 litre engine , was very laggy in comparrison to the MD195s from Turbo Dynamics..
I haven't had the benefit of mapping a T on a 2 litre yet , but would expect the T to be less laggy too...

dynamix

iTrader: (3)

Simple, get some drop in pistons for a very reasonable sum and then you can put a proper turbo on it rather than faffing around with 400 and wondering whether you have over-stepped the mark on power.

Life over 400 gets very exciting when you can put some proper boost through the car

If you were looking at staying at the 400 then the 321H sounds a perfect turbo for that level to have less lag than the OE turbo and fantastic top end. This will also keep it within the clutch capabilities. (my std clutch coped with 420+ lb /ft but was looking very tired when it got swapped)

scoobytyson

I am running the Owen 475+ turbo's on my Spec-c and am very pleased with it, hits full boost by 4k revs and pulls hard to redline

Damocell

iTrader: (1)

thanks for the advice, the upgrade is not for me, however i think it is worth considering all options

dynamix would you go for drop in pistons over other options like ceramic coated headers?/upgraded samco hoses?

Damo

dynamix

iTrader: (3)

Simple answer - Yes.

Get the foundations right and you would not believe how ballistic a 2.5 with a great turbo is.

JimmyBFC

Yes, to say they eeked 400hp out of it with standard airbox etc it was flawed to hell, nice enough car but nowhere near its potential, mine mapped at 410/390 (Evo 8) would be a lot quicker at spooling on just the standard 8 turbo.

dunx

iTrader: (3)

A std 2.5 will probably (?) let go in the high 300's as Prodrive want bucket of cash for theirs !
Decent pistons should manage, easy swap I'm told.... as I can't decide to jump to 2.5 or stick at 2.0 !

Alright it just won't die!

DunxC

dynamix

iTrader: (3)

Drive a well prepped 2.5 and your decision will be easy

dazdavies

iTrader: (22)

Have to agree with Dynamix here.

My 450bhp stock 2.5 block (fed by a rotated GT30R) was far nicer and had far better road manners than my 358bhp 2.0L (vf28) ever did. It was also ballistic when I nailed it.

Get a well set up 2.5 and you'll never ever look back, guaranteed!!

Tidgy

yep it was, and its one of the sore points, i got talking to brian owen at autosport a couple of years back. mits set them a boost limit of 3750rpm, which was the lag and ment that the car had to be driven a specific way to protect the diffs, driveshafts, clutch etc he seemed rather narked about the whole issue lol

Lateral Performance

iTrader: (20)

Surely you make a turbo that spools up quickly, and gives very good throttle response, and then map the boost to control the torque.

Butty

iTrader: (2)

How long do you need the maximum power to last for?

I'm about to add a TD05/20g to a std block 2.5 STi. The aim is to hit 400/400. Currently the VF43 is doing approx 340/380.
The 321 series did sound appealing, but its ability and cost seemed to be OTT when I don't want to split the block.

The car will be doing another 30k miles in the next 1.5 years before I sell it, so I don't want to stress the pistons too much.

If the 20g looses too much of the road ability of the ported VF43 then It won't be a large financial hit to swap back.

nick

Tidgy

not sure, way over my head lolo, all i know is the basics he told me lol, they had to keep it down due to restrictions on the spec

dynamix

iTrader: (3)

I'm with Mark on this one... why design a turbo that is bad on purpose?

Get a great responsive turbo and you control boost targets in the mapping to limit the torque in certain areas, but this is ultra responsive when called on the rest of the time.

and

Butty - you will not lose anything over the VF43. As good as that turbo is for an OE turbo, I overlaid some graphs of my old VF43 and the now much bigger MD321V and it whoops it in all aspects. At no point in the power graph does it let you down or deliver less than the std turbo but when it wants to and you allow it - it nails you back in the seat giggling.

Oh and btw you dont need to split the block to put pistons in

Butty

iTrader: (2)

Duncan,
After going to the trouble of getting the engine out and heads off, I'd consider just sliding some new pistons in as a bit of a cop out.

I'd also kick myself later on if I wanted to up things even further and had to do it all over again.

nick

dynamix

iTrader: (3)

Agreed - it is so much better when you have a built engine like mine from Area 52 Autosport that you can really abuse with a great turbo

2.5 bar of boost anyone ?



Let me tell you what it was like.... frikking mental

Neil..

iTrader: (35)

It's the same old same old this one...

The way I see it is this.

Option 1: 2.5 motor, drop in pistons, td05/6 turbo. Great set up, pretty much going to be troublefree, 400/400 no probs, and value for money.

Option 2: 2.5 built motor, c/w rods, hone to fit pistons etc, GT30 based turbo. Awesome set up, but costs initially are greater, and so are the costs for a twin plate clutch, 6 speed/PPG 5 speed etc etc..

It's all down to the folding stuff I'm afraid.

Damocell

iTrader: (1)

This is interesting, do you have a copy of the graphs you could post up please

Damo

Tidgy

define bad for purpose.

you spec up a 650bhp build then your not gonna chuck a td04 on it, the sppol rates good the final pwers crap. so put a turbo on that will run 650bhp and the spool is gonna be measure in coffee breaks compared to the td04.

think thats the issue, the spec they were given didn't allow them to have free reign and get the best and thats y its a sore point.

dynamix

iTrader: (3)

Original (this was after a remap too so the base STi figures are a lot less than this)



Now:



Nowhere on these graphs does the basic remapped 2.5 sti with VF43 even come close to the performance now.

Butty

iTrader: (2)

The "Now" graph is a bit more than just a turbo added to a standard bottom end though

Any graphs and a spec of how far you went with a standard engine?

Nick

dynamix

iTrader: (3)

We are not talking about std turbos here though.

The way I see it is that if you are going to spend money to get over 400 then you might as well go for 500 - the cost is very similar as the big hit is getting that first foundation right.

Anything getting close to 400 on the std block, pistons etc is ultimately squeezing a safety margin. i got to 360 / 420 on the std turbo (& exhaust/filter) and I thought that was quick for a while.

The point with me showing the graphs was to put some facts out there for those that say you would actually lose performance, pick up, response etc. It is simply not the case. Sure there is a extra spool period on the larger turbos but this is only noticeable because the bit that comes afterwards is so ballistic. In the meantime you are still pulling away from a std spec or even remapped car.

Butty

iTrader: (2)

Duncan, the OP is asking about turbos to go on an engine that won't be opened up.
I agree that if you are looking at over 400 then you may as well nudge 500, but that is another question.

I've seen answers on what the standard short engine can take as anything from 350-450ish, but there are exceptions at each end of this range.

As already said, i'm not pulling apart my engine and want to push further than a ported VF43.
The choices (to me) are a TD05/20g (on costs grounds) or an MD321 variant (too pricey and slightly over spec).

I've jumped onto the 20g, but is there another turbo that Damocell should consider, given his objective?

nick

dynamix

iTrader: (3)

We've also seen that dynos vary depending on which one you take it to ... you might make 400 on one - does that make your car faster?

Damocell

iTrader: (1)

Thanks for the replies guys, all good info.

TBH it isn't for me it's for a mate who has a remapped 2.5 STI and is looking for the next step.

He has been offered a package that includes a
400+ BHP Owen developments turbo,
ceramic coated headers
SFS induction hose
650cc injectors
mapping

to be honest I wondered if there was a better option out there as I didn't know much about Owen Developments, thats why I asked about pistons over ceramic headers.

After considering his options he is thinking about going for pistons and rods and then to pick a turbo.

What do you all think to the above options/any recomendations would be appreciated as I don't know much about 2.5 tuning and John is new to Scoobies. Looking for a fast road car and has all the suspension and brake mods already.

Sorry for the confusion.

Damo