boosted

Velocity, heat and pressure

JGlanzaV

iTrader: (3)

Yes. Keeping heat in, increases the velocity and in turn you need smaller runners to build pressure faster

gazney101

iTrader: (5)

I meant compared to the likes of a gtx3076r, 35r, 37r,40r rather than the garrett turbos you might find in OEM applications, as I'm sure your aware the billet wheels have mixed reviews but there's enough evidence for me to conclude that a billet version of cast wheel and of the exact same dimensions has got to spool faster.
The size of the turbine on yours should be about right and the up pipe a decent match providing the joints arent creating turbulence.
Sometimes internal gates can prematurely open as well so might be worth checking.
You got any dyno graphs?

gazney101

iTrader: (5)

What size are the runners on the killer b manifold?

JGlanzaV

iTrader: (3)

1.25" iirc

boosted

Ok re the garretts, as I said it is suffering from wastegate creep, the Dawes helps (opening prematurely as you call it)
The turbo has been on two days, less than 50 miles, not had any shakedown time at all, I gave it a quick tune up the road, that's about it. No dynos around here for miles.
Now the engine is on its way out, will be putting the 2.5 in tomorrow.
Re the billet wheels, I call BS, there is faaaarrr more innconel to worry about than tiny amounts of aluminium

boosted

engines are swapped, couple of things I noticed, lhs exhaust gasket was blowing at the head due to a slack bolt, cross pipe was also showing signs of leakage, there is also a massive mismatch in ports head-manifolds (worse than my others I just ported) inlet cam timing is also half a tooth retarded on same left hand bank (you think this would help spool).
Anyway the 2.5 is in now with ported and wrapped headers, higher compression, spot on cam timing, no leaks and an extra 500cc it can only be better.

BrownPantsRacing

iTrader: (6)

Well done. All of that ought to help give it a better chance. Be interested to see how this turns out.

boosted

I suspect 1 bar by 3800rpm and 1.5 by 4300rpm. Should be a fair tool

bludgod

iTrader: (3)

well get some logs up and lets see how that beast spins mr

boosted

Will do, it's on megasquirt standalone now.
Will run it in on mineral oil for 100 miles and then let it loose

boosted

Well that's a couple miles on the 2.5, some testing has proven that 0.5 bar is made by 2900rpm and 1.0 bar by 3600rpm. I can guess full boost will be around 4000-4400. Car is much more lively now, making more turbo noises lower down the revs.

BrownPantsRacing

iTrader: (6)

That sounds a lot better already then. Nice one!

ScottyPPP

Slap slap

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Yeah it isn't the quietest, but then what race engines are?
Second hand Pistons for £140 and second hand 2.5 casings for £250, £900 for the whole engine cost built (including cosworth gaskets, King racing bearings, new arp studs, rear thrust conversion, block pinning) is a cheap 2.5 engine. I can live with some slap for the 1-2000 miles a year it will do now.

boosted

Should pull like a train from lowish 4K once I lean it off and sort the boost control.
Be interesting to see what 1/4 mile time it does

duster

I had almost same setup, hx35 super twinentry or scroll whatever and i used a2w intercooler too, but ditched it, iat went too high, specially on trackdays. Changed it to lateral perfomance one and rotated manifold, to be honest i won more from lower iat's than i lost from longer pipng, but my piping is not as long as typically. How high your iat goes on high boost? Spool is very dependand on gear, i had 1,2 bar at 3300rpm in 6th and in first it didnt get more than 0.8 at all, wheres my spool? 2.5l brought it down ca 400rpm and there's a lot smaller difference betveen different gears. I wrote here only because i'm happy to see, i'm not the only one who had belief in a2w cooler and holset turbo on subaru

boosted

Awic is gone! Temps were getting too hot top end of third abf into fourth, near 60 degrees!
2.5 helped the holset, but it's gone too, I now have a 2.5 and 20g, not fully mapped yet but it is a far livelier setup on the road!
Ordered a flex fuel sensor and will be using it in conjunction with a meth mix to save having to be exact with the fillups.
Funny both our findings are the same re holsets and awic!
20g is ace on the 2.5, very quick to spool in first gear

duster

I wont change my turbo, i want to know what it's capable off, need to sort out my injector problems, now with sti yellows, they arent enough. I like how it behaves to be honest. I did get 45C at trackevent with 1,1 bar into 2l motor, it wasn't helpless and in everyday usage it was way better than original topmount. With that i saw 45C inlet temps when outside was -11C with one good pull

boosted

I ran the holset at 1.7 bar on the 2.5

boosted

No point having a turbo that size and running much less than 2.0 bar boost, that's the whole point of them

duster

Pointless is to buy 4 different setups, because always is not enough
I took straight bigger one and am step by step faster, just dont have money and time to get everything together. At the time i used 2l, it was bonestock ej205, didn't want to kill it. Now engine is done, cooling is done, only injectors and maybe ecu is left so i'll get to 2bar range soon and in general i agree with you. i hope i and my car can handle 2 bar on 2,5l engine, it may be overkill

boosted

I've had seven turbos, five engines, three gearboxes and five ecu's in my car in the three years I've owned it!
I've done fmic, tmic and tmcc on it too.
As its a daily driver I've now settled (this month!) for a high compression forged and pinned 2.5 with 20g, massive sard tmic, close ratio box, organic clutch and flex fuel system for methanol addition.

BrownPantsRacing

iTrader: (6)

PIcs of the latest setup please, or it didn't happen!

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Just looks factory under the bonnet I'm afraid! All go and no show

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