Maddog
28 January 2004, 12:37
For 550bhp/500lb-ft
What turbo do you recommend for this power level?
What turbo do you recommend for this power level?
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View Full Version : Groupbuy for US STi short engine Maddog 28 January 2004, 12:37 For 550bhp/500lb-ft What turbo do you recommend for this power level? Pavlo 28 January 2004, 13:20 I think Andy is a bit wide of the mark with the 550hp version, and I would say it costs more, at least to have peace of mind. JE pistons are not as easy to sort as you may think, at least properly specced ones. Especially as JE UK (perfect bore ltd) are charging rip off rates, and getting from the US requires you get a specific spec for this power output, not the bog standard EJ25 version. Eagle rods, maybe, maybe not thanks. Plus there is ALWAYS things that creep into the costs that you like the look/sound of. I would add at least another £1k to that figure. And as such, would echo Andy's comments about 400-450hp being a sensible palce to stop if you have the oodles of torque. People keep saying you need a big turbo to make the most out of it, I disagree. A smallish turbo means zero lag (like none whatsoever) and flexible engine, something that might be night in a daily driver for people that don't want a turbo engine. Paul Claudius 28 January 2004, 14:08 Hmmm.... so do you guys all want 450/450 tq and pwr engines? :D Gearbox, turbo, injectors, cams, bolts and what not, yes. BUT: you can still just get the bloc and gaskets and fit it to your head without changing everything at once, right? I would consider getting the bloc fitted and to run the engine in for a while at 1 bar or so while saving money for the rest. Andy.F 28 January 2004, 20:47 iON have a Garrett hybrid 550 bhp turbo at approx this price. The Eagle rods are well proven on high power/high mileage V8's running much longer stroke, higher rpm and heavier pistons than the 2.5 scoob. I think they know what they are on about :) The std pistons would probably run to 550 bhp ok but nobody will believe that (yet ;))so I recommended JE's Money - Perhaps you have not driven a 420/420 2.5 if you think the 2.0 can do a similar job ! The throttle response and bottom end torque from the 2.5 is in a different league ! Claudius - Even 1 bar on a 2.5 would break the 5speed box ! Andy M0NEY 28 January 2004, 22:23 Money - Perhaps you have not driven a 420/420 2.5 if you think the 2.0 can do a similar job ! The throttle response and bottom end torque from the 2.5 is in a different league ! Your right mate, i havent I was jsut pointing out to go the 2.5 with 420/420, you need soem mods behind this and it all costs money. At the end of the day, if you want a good figure of just over 400+bhp and 350 torque, might as well stick with the 2.0 and your lovely turbo! lol :D Pavlo 28 January 2004, 23:10 Andy, The Eagle rods are good I agree, and if the rods for Subaru are designed with a similar spec in mind then worth trying. Std pistons are good, but not great if you want to start tuning with occasional bad det. I heard that cast pistons may even crack the ring land if you hammer them once too often ;) www.cppistons.com also do pistons for the EJ257, aswell as custom ones, I beleive these are what Axis Power Racing have used in some engines. Still not as cheap as US V8 parts yet, but getting better! Paul Andy.F 28 January 2004, 23:47 Std pistons are good, but not great if you want to start tuning with occasional bad det. I heard that cast pistons may even crack the ring land if you hammer them once too often Hahaaa... Paul do you remember how come I had bad det with the JECS chips ;) Using a 'proper' ECU and 'proper' tuning methods it is possible to avoid bad det during set up. Std UK pistons are standing up nicely to around 210 bhp/litre at the moment, the limiting factor being the crappy turbos they are running ;) not the pistons. Andy David_Wallis 28 January 2004, 23:58 you still supplying turbos then :p ;) Andy.F 29 January 2004, 00:02 Yea, you still supplying boards ;) ....hint :D Maddog 29 January 2004, 07:55 This talk about rods and pistons and stuff which i know nothing about. What about other companies? Are Arrow rods any good for 2.5? harvey 29 January 2004, 12:15 Arrow rods have a very good reputation but are not the cheapest. Pavlo 29 January 2004, 12:39 Andy, Of course I know why you had bad det! However, the point is that the forged units are just more sypathetic. If you're into experimentation with nitrous and the like, it might pay to just have better pistons. The forged pistons have better thermal conductivity to take heat from the crown to the skirt, which can help. I kinda think going a little beyond the spec of the std shortblock isn't worth it, it's a lot of expense, so you may as well spend another £5-600 and get the best parts you can afford. Also, the earlier long skirt pistons seem to be worse than the later versions as seen on 97-> engines, which are also lighter. Paul [Edited by Pavlo - 1/29/2004 11:40:12 AM] M0NEY 29 January 2004, 14:10 Also, the earlier long skirt pistons seem to be worse than the later versions as seen on 97-> engines, which are also lighter So very true! lol wrrjones 29 January 2004, 14:51 just to let peeps no im running 1.4 bar through mine atm but runns out of puff at 5k but no lag making full boost at 2400 rpm and all going well ....chris tweenierob 29 January 2004, 16:26 I can see where you are coming from Money, but... They are two different beasts:D Having first hand experience driving and being a passenger in a car that started off as a 2.0 and now has a US 2.5 they are two very different engines IMHO. I know that they share the same layout etc and am finding it hard to summarise but although the torque can be made on a 2.0, making it on a 2.5 is much easier. On chris's car which was run in and played with on a fairly small turbo (VF24) the torque is madness!! IIRC it hits a bar of boost at 2000rpm is much more responsive ect ect, now i know things are gonna change with the 'big' turbo and we will report more but IMO 2.5 is deffo the way forward rather than an equal IYSWIM? Rob Andy.F 29 January 2004, 18:13 With you on that one Rob :) Jay m A 29 January 2004, 18:44 Somebody asked for UK shipping companies. Our company use EUROPA (http://www.europa-worldwide.co.uk) to export to the USA. We have never needed to ship the other way, but for reference, This month 10x150kg pallets went by sea for £2.1k door to door. Also 1x200kg pallet went air freight for £500. Justin dowser 29 January 2004, 20:25 Torque talks - the earlier the better :) M0NEY 29 January 2004, 20:52 Sounds good Rob. So people can put in a 2.5 and do absolutely nothing else to the engine and they can be hitting more bhp and torque than they would with a 2.0?? Pavlo 29 January 2004, 22:28 M0NEY. Yes that is correct. Bigger displacement means less pressure required which automatically will lower the intake temp. Although a larger turbo will work nicely, TD05 or even VF series become nice options for lower power yet flexible engine. Paul M0NEY 29 January 2004, 22:43 Cheers Paul :D BoxerFlat4 29 January 2004, 23:14 Thats my (possible) intention. Get the block and pistons, and progress from there. john banks 29 January 2004, 23:47 Don't think you will get significantly more power from just switching to a 2.5, you will get more torque certainly. You will be on a different point on the compressor map, but probably hit the same power obstacles. The spool up on a 20G with a 2.5 is hilariously good, I wouldn't dream of using something smaller, below 2000 RPM under significant load the engines are grumbly anyway like all turbocharged Subaru engines. By 2500 RPM it is pulling hard with a 20G, by 3000 RPM you better be hanging onto the steering wheel hard. 2.0 engines can eat anything a VF can throw at them with ease, no point in ruining a 2.5 with one of these abominations IMHO ;) smellyvag 30 January 2004, 01:07 Can anyone tell me what type intercoolers people are using with these 2.5 conversions. Have a choice of HKS fm or Sti 5 topmount. harvey 30 January 2004, 04:20 Chris: Very interested in what you are saying. What turbo are you running at present? M0NEY 30 January 2004, 09:50 lol @ John Sounds like good stuff :D :D :D Claudius 30 January 2004, 12:23 So... if I buy a 2.5l block with crank / rods / pistons, what else do I need to fit it to my MY97? Sump? Gaskets? A 6 speed Gear box? :D Another propshaft I guess? TopBanana 30 January 2004, 12:44 Group buy on Type 25s? Might work out cheaper M0NEY 30 January 2004, 15:47 Group buy on Type 25s? Might work out cheaper ROTFLMAO! Yep im up for it :D wrrjones 30 January 2004, 18:02 quote: Chris: Very interested in what you are saying. What turbo are you running at present? Harvey is it me you are asking .. if so the turbo is pathetic its a VF24 and was on my 2.0 and used on the 2.5 for running in .... chris [Edited by wrrjones - 1/30/2004 5:12:06 PM] |