why do evo's produce so much torque for 2.0
 

hey folks just been trailing through some mlr threads and seen some cars are running

400 bhp with same amount of torque

im just wondering how they do it

ive got a 2.0 blob sti with an 321t (with supporting mods)

but i dont think im hitting anywhere near 400 on the torque

anyone know why the evos are so high

cheer

steve

There are soo many variables here mate, I'm not sure it's the case that all Evos will make better torque than scoobies! My general impression, if you're comparing UK Evos and Scoobies is that evos have stonger internals good for more boost and boost is what makes torque so I guess that might explain it in very broad, crude terms?

On a well set up STi running an MD321T, you should be seeing the best part of 400 lbs ft torque though. If not, there may be an issue with your car's specification/mappoing as opposed to a generic issue with the type of car!

Later JDM scoobs have better engines than the Evo's ;) but twin scroll engines dont half help in the torque department :D

Tony:)

Cams..

Am I right in thinking a lot of the scooby crew don't look into cam changes til over 450-500bhp?

Good cams on an Evo bring both increases in power and torque.

In what way?

They rev higher because the jdm models have forged pistons/rods?

The JDM's have different internals, high intensity cast pistons, but that is just part of it, better crank for oil distribution, only known 1 blow up and thats because the owner didnt have it mapped for uk fuel and ragged it against a bike (he is on here btw ;)) but the equal length manifolds help with torque, the engines are proven to be stronger than the evo's (unlike the classics which were a fair bit weaker :() otherwise 80% different to the uk 2ltr engines.

Tony:)

Nice Tony, if I went back to a scoob it would be a Spec C from what i have seen (Rob North's old one was a great car)

Ah !!!! you mentioned spec c,this could become an epic thread.... :lol1:

My Hawkeye Spec C with basic mods produced over 400ft/lbs torque ;)

It's basically because the Ev* has a longer throw crank as std. my pal Ben is building 2.3 strokers for them using 100mm cranks. Our 2.0 uses 75mm and the 2.5 uses a 79mm crank, thus more torque from an Ev* for a given engine capacity.

All IMHO.

dunx

proven where and by whom????? Just interested as I jumped from a scoob into an evo 8 and to me it is a more solid car and better base for modifying

There is some truth in it bud, the jdm model sti's and Spec C's have a lot stronger and different internals than the type uk Inpreza's, higher rev limit, like you would have on a forged evo.

Evo's seem to be better for getting more power, more easily, and will run 500-600 fairly reliably if put together by the right person with the right supporting mods.

If thats the case mate then that would explain a hell of a lot :thumb: My 2.3ltr made 562lbs on a lowly gt3076 :confused:

so could the newage scoob never use a 100mm crank?

or is 83mm the highest

steve

The Evo has longer throw crank??? - damn (Why was I not informed of this earlier :mad:), after three scoobs and all this faff I could've just bought a bloody Evo and got all my low end torque without pricing 2.5 conversions just to get the low end torque back....


...Off to hunt some dyno graphs now ....and dealerships

As me albeit mine's a classic. I'm just shy of 400hp with almost same torque :wonder:

TX.

ill get a power run see what im sitting at

steve

yep I realise the jdm and spec c have a higher spec engine than the type uk but I didnt think they were still stronger than the evo's? (based on a 7 upwards?)

Yep! Long stroke engines have the potential to make good torque. The over-square configuration of the 2ltr is at a disadvantage in this respect. Also, the large piston dia. increases the potential for det.

JohnD

im making just over 450 bhp and 400lbft, would be nice to see a graph of a evo and scoob side by side with the same power, justto see how they compair, power lasting longer in the rev range etc

just my 2 pence
but is it not alot to do with boost pressure?? my bud runs his evo at around 1.8 bar... i dont dare run my scoob over 1.4 bar... ( remapped ) high boost..

I think evo 8 runs 1.5 bar standart???? :wonder:

You've come from a UK sti to an evo that's what i would fo done if i were you ,but had you gone down the Jap route you never would of botherd. Jap sti's and especially the spec c engines are just as good as evo engines for reliabilty and tunning if not better. Alot of evo figures are also exaggerated.
I had a 400bhp/400ltb 9 gt and it was no fasther then my 2006 spec c running 360bhp/360ltb. However the spec c was the much better handling car out the box by far.

Immy

+1

I thought the evos with the iron block 4G63 were just that bit stronger than even the JDM EJ20s.

Nope, the jdm twinscroll unit is stronger than the evo's unit ;)
Its cheaper to get more power out of the evo but the standard sti engine is more reliable than the standard evo's.

Tony:)

Gearing helps, my pal's 2.3 Ev* pulls at 40 mph in top in a way no < 3.0 Subaru turbo ever will....

My Imp could hold it's own against a 205 GTI, except where torque came in, i.e. out of tight corners, and up steep hills. Similar power, but way lower torque, 6.037 crank throw IIRC, and a 10.000 rpm limit :)

dunx

My spec c pulls at 35 in 6th (310-320bhp), goes all the way to the top, better than your mates evo 2.3 by the looks ;) (you can happily drive around town in 5th at 25mph in the twin scroll cars and they will still pick up :D)

Tony:D

at the end of the day evo's & scoobs are both great 4doors family cars that would wipe the floor with most sport cars out there, there both great in there our way really no point saying 1 is better than the other bcuz there's always some think you can mod on them to make them better.

well im running 1.7 bar and i wouldnt put it any higher without a CDB

what can and evo 8 run safe on standard block with mods like bigger turbo headers etc

and what is the max crank and impreza can have

steve

You need to go on you tube and have a look around ;) pretty much everything on there from 2003 model year cars onwards ends up with the scoobs ending up finishing first (most of the time starting from the back of the pack ;)) way ahead of the evo's ;) it was different with the classics, it was very close with the early cars, then the evo 4 made the breakthrough with ayc, up to 7 they had the edge on the scoobs, since then they have been second place as subaru have kept on top of it all, just dont mistake a UK spec subaru to a JDM one, many differences and not as good tbh.

Tony:)