RSA99

My current engine has just failed (suspected burnt out valve or land) and I'm looking at this as an opportunity to refresh the car (GB270) and enjoy it for another 10 years by having an engine built to my specs.
The car is used for fast road use and the occasional trackday but, I have kids and it is also used for holidays and days out and has to be reliable.
I like the idea of having a more-revvy engine and could easily be pesuaded to swap to a 2.0L as I am told they are more bombproof (?) (lights the touchpaper and retires ;-))
I am looking for about 400-450bhp but, not headline figures over reliability.
I have accepted that I am also going to have to swap the gearbox for a 6-speed.
I love driving the car and would be looking to develop it further to make it into an even better drive.
So, gentlemen, I'm after advice over what spec engine I should have built please?
Cheers,
Rich.

Danjo

You could ask ten people that question and get ten different answers, so my advice is pick a builder with a good reputation and speak to them. There’s a few different ways of going about things. Also, you might want to decide if you are looking nearer 450 or nearer the 500 end of the scale as 450 can be achieved for a fair bit less than a good solid 500bhp setup. You also need to factor in whether you want headroom for the future if you decided you want more power.

450 can be achieved on a fairly simple scdb with standard rods and upgraded pistons, whereas 500 it’s wiser to go down the route of closed decking, forged rods etc.

I have a built 2.5 running 560bhp/600lbft and the torque for a road car is incredible. Revs are nice, but are you always going to want to use them every time you want to press on? Might be worth having a go in a car that revs vs one with good low down torque.

Here is a prime example, below is my graph running a stock location Precision 5530:




and below is the same turbo on a 2.1




Both make good power with the 2.1 being the revvier engine, but the 2.5 is making 180lbft more at 4k rpms.

There’s no right and wrong answer of course, as each is to their own, but it’s a good example of what you could expect between the two.

johno01

How deep are your pockets mate?

RSA99

Thanks Danjo :-)

As you mention, it is a very personal thing as to how we like our cars to drive, but, for me, I love the sound of a well-tuned, revvy engine.
I previously had 2.0L turbo WRX and although it was nowhere near as tourquey as the 2.5L, it revved well.
I also find that having an engine that you have to rev to get the performance out of it, leads to a lot less situations where you are travelling a lot faster than you think ;-)

I would be more than happy with 450bhp and have no future desire to have more (I've done the very fast car thing) as long as it's well-engineered and reliable.

With that in mind, what should I be specifying, to allow a free-revving reliable engine?
Steel crank? Forged Rods? ?
I don't care if some are overkill for this power, if they result in increased reliability.

>>Might be worth having a go in a car that revs vs one with good low down torque.
I know it's probably the wrong time of year, but, where are some good meetups near London, where I could chat to some people?

Cheers,
Rich.

RSA99

Is £7K or less realistic for this?

johno01

id probably guess that 7k will get you a well sorted engine build-whether that be a forged 2 litre or a forged 2.5….then factor in another few grand for the 6 speed conversion with labour then factor in another few grand for the 450 bhp mods and labour…there’s a lot more to it unfortunately 😭

johno01

Make sure you stick with us though as we love a good thread on here 👍🙏🤞

RSA99

I certainly will - I'm after all the good advice I can get :-)

JdmSti2006

jdm forged 2.1 and jdm 6 speed plus quick rack if You like Your car much

stockcar

for a road car a well built 2.5 is a no brainer IMO.........revs are simply a side effect of AIR - fit the correct turbo / valvetrain and the 2.5 will rev quite happily
at 400+ on an EJ25 you will require a CDB insert conversion and probably 14mm studs whilst aiming for beyond 500 / 550 means starting to look at more involved solutions as @Danjo has completed above

RSA99

UPDATE:
I've gone for something conservative (and not too costly).

EJ257 RA crate short motor, full overhaul, pressure test and skim of cylinder heads, RCM 11mm head stud and stopper Headgaskets, 11mm oil pump, RCM metal exhaust cam pulleys, Cambelt kit and water pump.

I still need advice on which turbo to go with this setup...

TD04-19t/20t or vf43 ?

I've done a bit of research - TD04-19t/20t spool up quicker and give better low-down torque? ...vf43 (fitted to STi?) gives it's power further up the rev-range?
If that's true then I think I would prefer a VF43...I like revvy engines

Is there any point in fitting a lightened flywheel to help the engine rev?

JdmSti2006

For 330 horses and 6k revs You do not need lightweight flywheel, You need 335d