dazdavies

iTrader: (22)

Single walbro 255 lph pump teed off using -6 goodrich hoses and fittings. (forged elbows etc)

Still havent decided on which turbo to go for whether twisted or the MD321t.

The clutch decision was purely down to money for the time being. I already had a half decent clutch that will be ideal for running in. The whole project has cost me a phenominal amount of money. I simply cannot afford the twin plate just yet. and changing a clutch after the car has been run in for me is no major hassle.

Daz

P20SPD

iTrader: (1)

Doug, doing that and using sti5 valvetrain, transformed the feel of my 2.5 engine.

P20SPD

iTrader: (1)

Can see where you are coming from.

What boost would you be running, dependant on turbo, and what fuel pressure at atmospheric will you be running?

dazdavies

iTrader: (22)

I Haven't read up on fuel settings yet so haven't got a clue. Will set the SX at 3bar to start but The car will be mapped for its first start up anyway and I'm sure the mapper will know better than i what to set this at.
As for boost the most it will ever see is 2bar but thats for special occaisions

I will probably have the everyday setting at 1.5 bar then a 1.75 bar and a 2bar setting for drag days and stuff. these are all peak figures of course.
Any advice on this will be appreciated.

hypoluxa

Go for the smallest you can get away with, I've recently gone from a gt30 to a T68 and then back down to a vf35 for a recent trip to the Alps. This is on a sleeved 2lt. Over 2000rpm+ difference in spool between them. T68 flows twice as much as the vf35, but neither the 30 or the 68 would have kept up with the 35 when going up the side of a mountain Horses for courses. For 2bar I would use a Garrett ex housing rather than bolt on.

David_Wallis

Daz,

Choosing what boost you want to run, before you choose the turbo is silly

David

doug2507

iTrader: (6)

Without going rotated (will come at a later date if needed) the best choices seem to be either a TD06-49/MD321 or a GT30 hybrid. Would there be much benefit with a GT30 (non-rotated) over a TD06-49? Looking to keep lag down to a minimum with a nice smooth torque curve. Mine will be mainly used for the hills/sprints so really need a good 3-4000rpm spread. Boost is not a concern as that will set by Andy when mapped.

P20SPD

iTrader: (1)

My old 2.5 is currently fed from a TD06-49, and that is anything but laggy IMO. Full boost in top gear is achieved before 3000rpm.

As i understand it the latest incarnation of the MD321 is somewhat of excellent turbo on the 2.5. IIRC the MD321 uses a garrett core anyway.

Suggest you speak to someone like Mark, who would probably answer your questions better.

The only thing i can say, is, if i wanted a torquey/punchy low lag daily driver/sprinter, i would buy back my old engine and use the turbo that is currently on it/or the MD321 latest variant.

911

Interested by the last para in Stephen's response above.
That run of words describes a hillclimb engine.
What turbo is on it now?
Graham

David_Wallis

There you go..

Id try the latest variant of the 321

David

hypoluxa

How can you choose a compressor wheel without knowing what PR you are going to run?? Buying a turbo then finding out it is inefficient for your boost targets is silly!

Tis like buying a car then trying to fit the dog in then realizing you should have bought a Volvo rather than the Elise

p1mark

I personally think Daz is going about it the right way. He has built a bottom end that is capable of supporting say 2.0 Bar and has the intention of using that.

He has a power target of minimum 450 BHP

Presumably he has a fuelling/ECU/intercooler set up to cope with both these figures.

Now he just has to choose a turbo that will do that within the constraints of his max safe boost. simple in my eyes or am i missing something?

David_Wallis

Not really, As I suspect if he rung mark for example, he wouldnt discuss PR, effieciency, etc..

Im sure he'd ask the goals and advise from there, for example buying the same turbo as me and trying to run the same boost as I do on his engine would destroy it pretty quickly.

saying I want to use "2 Bar" on a turbo will produce very different results between something like a GT25 and a GT72.

There are also big differences between the air something like a twisted GT30 and a TD06 will flow..

David

P20SPD

iTrader: (1)

Graham, all i can suggest is try meet up with Alan Bell and drive his STi7, you will be amazed IMO.

Alternatively, take a trip up to Scoobyclinic and ask for a go in their 22B, again, you will be amazed IMO.

dazdavies

iTrader: (22)

Mark, thanks for the vote of confidence

David, don't kid yourself I have no doubt that your engine kicks out more power and is marginally stronger however.I have put a lot of time effort and money into this project. Its not just some throw together nonsense its been thought about, discussed and planned to the last. The only thing I havent decided on yet is my choice of turbo. In my eyes there is only a choice of two turbo's and that is a rotated GT30R with a .63 AR or as has been mentioned many times the latest incarnation of the MD321 in this instance the MD321t.

I know that my build will cope with both of those turbo's easily. I want everyday drivability but I also want something thats quicker than most things out there for that surprise fast road fun element.

For example my best mate has a Norris designs Built evo 6 thats circa 600bhp.

Its incredibly drivable its also a high 10 early 11 second 1/4 mile car.

If I wanted anything wildly above 500 bhp I have to be honest and say that the subaru engine wouldn't be my first choice.

I have had my aim at between 450 - 500 bhp since I bought my first scoob nearly four years ago. That said however more important to me than pub talk RR figures is what my car performs like on the open road on a day to day basis. That and monetry constraints are the two and only reasons I have gone down the route I have.

I am also proud to say that no tuning companies have been involved with my little project other than supplying parts and the occasional opinion. Even my closest friends have to view my progress through this thread. Infact the only external help I have seeked was the rebuild of my six speed gearbox as I know my limitations.

I have spent hours and hours researching and reading up on this and I have no doubt whatsoever that my aim of a reliable quick 450 - 500bhp road car will be achieved. I'm no mechanic or tuning guru I just have a hobby that I enjoy and as with everything I do, I try and do it the best I can.

AS for fueling, Intercooler and ECU simple:

Walbro 255 lph pump.
Denso 850 injectors although thinking of 740,s but I got the 850's for £100 on ebay
My Ecu is an Apexi Power FC and boost wil be controlled by the apexi AVCR
Intercooler will be the biggest and probably cheapest Bar and plate I can find a favourite at the mo is the Autobahn88 ones that I have seen closely and will do the job just fine.


Incedently I am waiting for Mark to get back to me as I will be buying whatever turbo I go for from him. I am just wating for his opinion based on my aims and spec.

I hope that answers a few questions and puts the cynics amongst you to rest for a while

Daz

P20SPD

iTrader: (1)

Dont think David was being a cynic of your aims Daz, as you clearly state, you certainly appear to have thought it through.

As for your choice of turbo, if you have an immediate money constraint, go with the MD321t. If you dont, or are prepared to wait a little longer to save the cash, go with the GT30r rotated.

As for your injectors, i would seriously suggest popping them back on ebay, the 740's are so much better all round IMO.

I suspect you may have to run a bit more fuel pressure at atmospheric, say 3.5 to 4bar, to achieve the 450~500 target safely, at which point, you single pump could struggle.

When i ran my GT30 on my 2.5 with 850's @ 3.8bar ATMOS, and 1.3 bar boost it was ok fueling wise, but when i stepped up to 1.6 bar, fuel pressure would start dropping higher up the revs.

hypoluxa

David,

You suggested he should buy a turbo and then decide what boost to run. I'll try and explain a little better why this is a poor way of choosing a turbo.

As an example, to make 500hp from a 2ltr on oem cams you need around 2bar boost (although this is highly dependent on a number of things obviously)

The 60-1 and the ht200-1 have similar flow rates and are both capable of making 500+hp. But the 60-1 would be utter kak in this scenario. It is most efficient at around a PR of 2, and has a max PR of 2.6. The HT200-1 on the other hand has a similar efficiency but at a PR of 3, and can support a PR of 4!

So if you bought a 60-1 and with the aim of trying to make 500hp from a 2lt you would be buggered. This is why we have compressor maps so we can see PR's, efficiency, flow etc. These should all be taken into acount before buying a turbo.


Daz,

We made 450hp @ 1.5bar on a 2lt with the 49lb wheel, It is an excellent wheel - good for 2bar too (we used a different exhaust side to the td tho)

I think a GT3071 is also worth a look (alongside the aformentioned .63 3037) if you want to sacrifice a little pub talk for better response

You are right to be confident in your build, I ran a stock sti4 b/e at 2bar on a gt30 and it didn't break, my current 2lt has ran 2.6bar. A good build with a good tune will last. Good luck

BTW I run 850's and fine them fine

dazdavies

iTrader: (22)

hypoluxa

Thanks for the reply which contained some very good points.

Based on tonights progress and the positioning of the fuel lines and breathers my turbo decision has been made for me.

Due to all the restrictions with the intake routed under the inlet manifold I think I am going to stick with my wishes and go for a rotated GT30R .63 AR(3037).

Its just a shame that no one has a 2.0L with one of these fitted that I could be taken out in so I can make an informed decision.

I may even change my mind if someone could do the same with a MD321T equipped 2.0L too.

Another thing thats influenced my decison was Olly Clark at Scooby Shoot out I mentioned his 20G hybrid and the MD321T and he said completly off the cuff and was genuine that whilst the Hybrids are very good Turbos I'd inevitably wished I'd gone rotated in the first place. So with that in mind its going to be the GT30R (3037) rotated with external waste gate and a .63 AR.

So that leads to my next decision what size Waste gate 38 mm or 44mm

Daz

hypoluxa

I would go for a turbosmart 38mm, the 44mm looks the part and comes with v bands but is heavy and tricky to position.

p1mark

Im no turbo spec expert by any stretch of the imagination but if it was me (and i had the patience to save up which i dont) i would go for a rotated GT30.

All other things being equal - and ignoring the costs - it has to be a step up in response and power from a similiar sized turbo in the o.e position.

Nice one Dazz . Do you have any estimates when its expecting to hit the road? Have you thought about putting your old Turbo/injector/ECU set up on so you can get it fired up and ran in?

Great thread BTW - It just shows that a non mechanic (your words - no offence meant) can do a top job on an engine build, all it needs is a bit of common sense and the odd pointer from people who have done it before and its not bad at all to do - and highly rewarding.

P20SPD

iTrader: (1)

Got to agree Mark, but the trouble with this is, if Daz is anything like me, your bored stiff after you have completed it

I am beginning to like the building and tinkering more than driving now

Daz, good choice re the turbo, you have made the right decision.

Steven

David_Wallis

Daz,

Im not being a cynic, just dont make the mistake of buying something now, and then regretting it later by having to sell at a loss.. with a rotated setup you can change turbo specs a fair bit easier and cheaper without having to change the exhaust.. (fair enough you dont change the exhaust with a hybrid, but you know what I mean.!)

Erm,

No I think my engine is possibly a lot stronger due to the fact I have top hat flanged liners, its been machined for studs that are bigger than most on the market, and has a lot more mods done to it than meet the eye.

If you want to know the other differences then drop me a mail as theres a lot more gone into it than putting rods, pistons, bearings in a block and saying the uprated short motor will do xxxbhp.. Im not taking the **** or stating the obvious, but there a things that have been done to my block / engine 4 years ago, that most people still dont do now..

hypoluxa

Im well aware of that, but without seeing a flow map, you wouldnt choose the boost iyswim.. its down to the amount of air required, but this is irrelevant as we are both well aware of this..

David

dazdavies

iTrader: (22)

I have thought about puttingmy old setup in and getting it ran in however, my thoughts are if it needs a remap as I have bigger pistons and I have also changed the fueling to a parralell setup with a reg then I may as well just get the new turbo and bigger injectors mapped for a running in map.

If I didnt have to do a remap then I may well go down that route. I am getting impatient now and want to be driving it again.

No offence taken either and thanks for the compliments

p1mark

Im the same - so i continually tinker with it even though its on the road. that way you have a new car every week.

j healy

just reading through the thread daz.slowly giving me the confidence to rebuild my engine if anything ever happens to it(with help from p1mark )
don`t know if you are interested but i have a set of nismo 740cc injectors that were fitted to my car for about 3 miles before being replaced for something alittle smaller(cold start issues and alittle over the top for my needs),they have had the connecters cut back to fit my p1 and may need a clean up(they have been kept in a box in the garage)but you can have them for next to nothing if it helps.

dazdavies

iTrader: (22)

Jason I have sent you a PM regarding this.

Right then some more updated pics and progress.


I still have no idea what variant to put here.

http://www.scoob.co.uk/rebuild/whatshalliputhere.jpg


Almost finished
http://www.scoob.co.uk/rebuild/enginebay1.jpg

http://www.scoob.co.uk/rebuild/enginebay2.jpg

The other ongoing project although this one has now finished. It may even upset the purists out there but this is my Stereo intsall in the boot

http://www.scoob.co.uk/rebuild/bootinstall1.jpg

http://www.scoob.co.uk/rebuild/bootinstall2.jpg


and here is a pic of the fool responsible for all of this , yours trully
http://www.scoob.co.uk/rebuild/yourstrully.jpg

Not vanity before you start lol just thought i'd put a face to the thread

P20SPD

iTrader: (1)

Thought you HAD decided ?

dazdavies

iTrader: (22)

I kind of have, but i'm so bloody desperate to drive it and the twisted stuff is alot of money when you start thinking about up pipe, down pipe, turbo, wastegate, fitting kits etc. Plus the fact that my tubular manifold is the three bolt flange type. I'm still soooooo tempted to have a go at the MD321t.

If money wasnt an object then it would be the twisted option every time

www.confused .com

osterley

Think you've chosen the right route now

dazdavies

iTrader: (22)

Sold my down pipe now anyway so twisted GT30R it is!!!!