Hi guys

My engine is almost done, its 2.5 with following:
Wiseco pistons
Manley rods
ACL bearing
Mocal oil cooler
Cosworth head gaskets
ARP studs
RCM airfiler
Walbro 255
FMIC
Parallel fueling
740cc injectors
Fuel lab FPR
full decated exhaust
Apexi power FC maybe will change to a Symtek
port and polished headers ( up-pipe will be harveys to match the turbo)

Oh yea its a typeR 98 and i am still running the typeR gearbox with Exedy 3 paddle clutch, im not looking for big numbers because i know my gearbox cant take much, i will be changing to 6 Speed soon, but even with 6 Speed gearbox im not looking to go far from 400bhp if i can even get there. Baring in mind that this is my 1st forged Subaru engine and i have no idea what results this can bring on the rolling road.

I am not sure what turbo would be a good combination to what i have done i have heard that TD05 20G can be mental with 2.5 engines but dont want to buy until i am sure about it.

any comments welcome

Cheers
Shaks

 

i run an 05 20g on a 2.5 and it makes for a wicked road car, quick spooling and awesome mid range punch and had the bonus of being a cheap turbo, currently running 436/460 (with meth) if you want more than that look at the sc46 turbo which buy all accounts is a great turbo !

 

MD321T is good on a 2.5

 

get your self a md321t turbo from mark at lateral performance, run the car on low boost until you have changed gearbox and when you have done that get it remapped and you can can run 450bhp/450 torque all day long through a 2.5 with forged internalls. been there and done it.

cheers mickyboy

 

SC46 Billet is awesome on a 2.5.

Martyn

 

My SR40 will be up for grabs in a bit with matched up-pipe. Dyno of it on forged 2.5 below.

 

Hi, I've got a fully built 2.5 and started with a 20G which was good for about 380bhp with an Apexi but then changed it for the MD321T on a Simtek which has given me 426bhp/462ft/lbs. That was 48000 miles ago and it's still going strong.
I have got a 6 speed box though which is the only way to run the higher torque

 

As MartynJ suggest SC46 Billet will be nice or MD321T.


Jura

 

No point in running a MD321T if you decide to stick with the standard box as you wont be able to use the full potential of the turbo.

This is when i ran the MD321T on standard V4 Type R gearbox on my 2.5

 

^^ Really small image fella!

TX.

 

 

Ay how did that happen

Sorted!

Forget 400 as figures, just go for a 18G or 20G, it will be mental!

 

Gt35/42

 

20g with a splash of meth

 

Peak torque @ 4750 on that size turbo (on a built 2.5).... doesn't best show that turbo off.

Still on the standard 5sp I assume?

 

had an sc46 on my 2.5 with just forged piston,

excellent turbo!, but made figures that would destroy your box tbh.

id really recommend getting the 6 speed asap

without it your setup is really restrained

 

what figures did you make and at what boost ?

 

420bhp, 435lb/ft IIRC. peak boost 1.35 barr

all off top of my head - and from a good while back, that boost maybe a bit out, maybe 1.5 dropping to 1.35, but reaaly cant remeber, sorry

but just with a set of forged pistons(as far as engine mods went )

 

Im going to have a 6 speed fitted on mine soon (saving up for it) but im not looking to go far from 400bhp so really 20g seems to be the way to go and its a good price too which wont hurt my budget.

 

youve overbuilt the engine then imo

unless later going to up it, couldve saved some expense and put towrds the 6 speed

however its done now, so get your turbo, and enjoy, im sure whatever you pick you wont be dissapointed

 

Yea i know what you mean, before i started my engine i thought about it, when i had my first scooby it felt really fast after a while it felt slow because you just get used to the power and you want more so when i started this project i wanted to over spec the engine so if i decide to increase the power at later stage i can do it without having to worry about re doing the engine again.

i think i will start with a 20G then i can always change it once i have the gearbox changed.

thanks guys i really appreciate your help.

cheers
Shaks

 

SC46 all the way. On my forged 2.5 it develops 473/482 with 1 bar of boost at 2700rpm.

You'll need a stronger box though!!

 

Here is a selection of what we have seen from built 2.5 motors with most of the turbos mentioned above and a couple more.

Billet SC46 on 20% meth



Same car on VPower Billet SC46 vs stock VF43



MD321V vs MD321T same engine 15% meth



TT S215 on 20% from memory



GT35R on an all Cosworth 2.5 engine VPower



GT35/42R on Sunoco Maxnos race fuel on an all Cosworth engine



From my experience of all of these, the SC46 Billet provides the best road car performance you could ask for with instant response and enough legs to keep it feeling fast at the top.

Martyn

 

wow some great results there thanks Martyn thats really helpful.

 

Graph two is the important one on Martin's thread.

Just look at the way the SC46 trounces the VF43 for peak power and torque (expected) but then managed to also beat it hands down on the way the power and torque ramp up across the entire rev range too! (less expected given that it's a turbo capable of producing in excess of 100bhp more than the VF43!)

Stunning turbo for road use.

 

A genuine 20G on a 2.5 litre spools quickly, produces shed loads of torque and is very cost effective. £850 new. 12 month warranty.
From first hand experience an SC46 will produce about 40 to 50 bhp more and is also a good choice but costs a good bit more.