turbo for 370-400 bhp on a 2.5
 

so as ive decided to keep my car i am never going to be happy until i get more power,ive been pondering about it for a long time now but ive got to give into temptation soon.

currently running a fettled with vf43 @ 350bhp + 370ftlbs

looking for around 370-400bhp with matching torque. dont really wanna spend a ****-load either if im honest.

which turbos would be best suited for it, no track work just a fast road daily

my engine is-

closed deck block built by scooby-clinic 11k ago
mahle 2618 pistons
standard rods with arp rod bolts
acl bearings throughout
up-rated head-gaskets
re-built heads with uprated valves/springs and retainers
standard 10mm oil pump

740 denso injectors
walbro pump
jap-speed fmic
3" de-cat downpipe with a full 3" afterburner system with vortex backbox.
ap racing clutch and xtreme lightweight flywheel
standard headers with unknown up-pipe (i will be looking for either rcm headers/up-pipe or as performance ported headers with trick up-pipe)

Will standard rods take much more ?

look into a billet wheel conversion as there not too expensive ,, I had a vf48 with a billet wheel and it made 398/400 and was a really good set up

im pretty sure my vf43 has a billet wheel as i have paperwork for it from cr turbos.

I would go for a SC38 or SC42 my friend runs a SC42 on his Subaru and it drives beautifully,spools up nice and fast on his 2.5 with similar upgrades to yours he's running 410 bhp with a tad more torque.People say the SC range of turbos are quite pricey,but i'm a strong believer in that you get the kind of quality/reliability that you pay for,plus you can sell your existing turbo on to recoup some of the cost back.After driving plenty of Subarus with SC turbos fitted mine included;) I know where I would be spending my hard earned money when it comes to turbo upgrades they are superb.SJ.

my hawk with vf43 made 368 without a billet wheel ??,,,,, my billet 48 made 398 on my hatchback

I'll be looking at the same on my new car. Want to break 400 but don't really want to go as high as 450 so was ideally looking at the SC42 turbo.

had three SC turbos fail on me so won't ever be buying from them again ,,, I'm sure they have sorted the problems now but iv moved on to another company lol

That's interesting Domino. Appreciate your cars are pushing over 500 now so what would you suggest for 420bhp turbo?

This is the same sort of power turbo im looking for atm, have you considered the Mamba turbo, couple of people on here with them and good feedback?

Many years ago I had an SC38 in the past. On a 2.0 it made 395hp. Was ok but i found it too laggy for me and ended up going back to a VF35 as i preferred more midrange punch.

More recently I've been looking to go back to around 400hp with the new car. Having done a bit more research, i shouldve gone for a ball bearing core turbo and will be going with either the TD MDX-555 400 or Lateral MDX321H,

Wastegate welded shut?

No be honest not really John. The Mamba range to me will always be on the cheaper end of the market and I appreciate they actually seem to be built much better these days and from what I've read there are quite a few people now successfully using these without issue, some even running 600bhp area on the bigger units.

I really want to ensure that I'm not killing driveability on my car. Currently running 335bhp & 420lb/ft on my vf48 with TMIC and it's great, spool up is lightening fast. I'll be upgrading to a Perrin FMIC that I have on the car soon and don't want to turn the car into a massive lag monster so would rather go with a very well engineered turbo as small as I can possibly go to hit 420bhp. Also don't want to play with meth etc to chase figures.

to be honest mate id prob be in the same position you are as I don't really know what would work well and will defo make 420 ,,, id be tempted by a forced performance turbo , only due to me having one on the hatchback now and it working very well and made the numbers they said it would ,, we all get nervous about what bhp they get in the states over what you will make here lol but it works well and was a lot cheaper than most uk versions of the same turbo ,, and Owen developments supports them

Good info thanks. Was also interested to look at the MDX range and Litchfield range.

Very interesting. Your's makes great power for a standard location turbo. How is lag on your setup though? Obviously it's going to be worse than a VF48, but is it still nice to drive?

Do Owens sell the forced performance turbos?

I think they do yeah but not 100% ,, I think it was on the forced website I seen that Owen was a stockist ,,,, I think mine drives great (but I would say that lol) ,, like anything with that sort of power there is a bit of lag but as long as your in the right gear its not really a problem and will still pull from quite low down due to the 2.5 , there would be ways to get mine to spool a bit quicker but I'm happy with it (for now lol),,, I was looking into the billet version with a ball bearing housing but the cost can't be justified for the bit of spool I would gain

https://www.owendevelopments.co.uk/m...d_Performance/


don't think they would sell a crap turbo lol

Difficult to see what turbo is supposed to do what power and only seem to list 2 versions on their site, one for 600bhp and other un-specified. Will send an enquiry off to Owens to see what they say.

Cheers.

My AFP Approx. from road dyno on my stock 2.0 with 30% bio-eth

Turbos was an SC42 that got the Owen Developments treatment, Bigger Billet Wheel, better beaings etc :)
https://cimg7.ibsrv.net/gimg/www.sco...9a82e3d3fe.jpg

SC38 + Harvey Smith trick up-pipe (for early torque) + Grimmspeed TMIC + Perrin CAIK + MAF-less tune on a 2.1 stroker:

https://cimg6.ibsrv.net/gimg/www.sco...c512110416.jpg
I'm no expert but I'd wager your 2.5 plus an SC42 could probably see a similar torque profile and a lot more top end.

Perrin FMIC kit for my car was £1600 and is very well engineered bit of kit. Personal preference on FMIC and TMIC really.

Also, Chevron don't make a TMIC for the 2015-2018 STI yet and FMIC kits are very limited.

Don't suppose you have a graph on normal pump fuel do you? I'm not really interested in making fuel cocktails to boost performance as mine is a daily driver and I just don't have time. I would certainly invest in the harvey up-pipe when I do change the turbo though and look to get the headers ported. Looks good.

I could be wrong, but I'm fairly sure the Japspeed units are made and supplied by the ebay seller 2fast2cool and are the same design. The Harvey up pipe was developed by Harvey Smith (God rest his soul) and he did a fair bit of testing to come to the current design which actually slightly narrows towards the turbo to create a faster gas entry speed into the turbo and aid spool. They work very well indeed.

Correction from a quick google, Japspeed & 2fast2cool are actually the same company and have the same VAT reg number. I stand corrected. Also it seems they trade on eBay as uk-performance-uk too.

20% Eth & V-Power

I run HS uppipe & GT-Spec headers
https://cimg4.ibsrv.net/gimg/www.sco...a46fdcdcb4.jpg

Exactly.

Just to put some figures on that, I fitted Harvey Smith ported headers and up-pipe as a standalone mod.
The ‘before’ and ‘after’ figures were from different rolling roads/mappers so obviously there’ll be some variance, but you’ll get the idea:

Torque lbs/ft.
Revs Before After Gain
2,500 125 170 36%
3,000 140 228 62%
3,500 180 308 71%
4,000 270 322 19%

Great results from such a simple upgrade.

https://www.scoobynet.com/general-te...-findings.html

Now sold by AS Performance.

https://www.scoobynet.com/trader-ann...d-headers.html