is it possible to improve m20 intake? s14 stylee?

Post Wed Apr 04, 2007 8:09 am

For more power above 260hp on throttle bodies the m20 needs bigger inlet valves and ports acordign to the ricardo wave sim software.

Crikey, so there's potential for more than 100bhp/litre on the standard head?! Impressive for a 2v design!

Post Thu Apr 05, 2007 2:51 pm

Ok these have come up for sale and i am sorely tempted but i am worried about 2 things:
1)will i loose control of runner length or not really as my throttlebodies will dictate the final length
2)i am hoping to knock something together that is not aimed at all out power increase but more mid to low end torque and throttle reponse - will the diameter of these have an adverse affect on what i want to acheive?
3)placement of incector? any ideas for overcoming this?

Post Thu Apr 05, 2007 3:27 pm

Hi

I run a set of these with webber 45's if you are going to buy them the easy solution is to use 3 jenvy (webber fittment) throttle bodies the thing is they are not cheap at Ã‚£200 each and you need three.

Jason

Crikey, so there's potential for more than 100bhp/litre on the standard head?! Impressive for a 2v design!

Close but my mate RK is build a 3.1l m20 and the simulation is based on that and his flow bench figures for a moded 885 head with standard valves.

Post Thu Apr 05, 2007 5:06 pm

What's meant to happen to the crank case breather with those manifolds?

The tuned length can be modified with the trumpets you use so don't worry too much about that Liam

Post Thu Apr 05, 2007 6:55 pm

Hi

On my manifold there is a 90deg elbow welded in to pick up the breather, I have seen others that just run it to an external k&n filter

Jason

Post Thu Apr 05, 2007 9:34 pm

VE can be calculated backwards from HP numbers and AFRÃ‚´s at the maximum HP rpm.

Max torque rpm = max VE of engine setup. anything above or below will result in less VE.

Post Tue Apr 10, 2007 2:44 pm

guys i am stuck with the ve number - I dont seem to be able to get it?

see i want to make my runner diameter so small that it 'almost' limits horse power, i would be tuning for peak torque at about 3700, but dont really know how to go about it. i dont want to even come close to running stacks that are to fat so i want to bass all my calculations on a peak horsepower of about 220 as thats just above what a highly tuned 2.7 can put out (roughly i know), so whats that about 38mm diameter runners? or could i go even thinner without strangling the 4000-6500 range?

i really need to get that ve figure... or is it alot simpler than all these calculations i'm googling - Maybe in parroting all these formulas i have found i am just overcomplicating what can be a relatively simple procedure...

Post Tue Apr 10, 2007 2:58 pm

mm further reading suggests i must tune in relation to current engine setup regarding cam and bare in mind what torque and bhp i currently have
god this is getting too complicated all together
currently it feels like max torque at 4300 and bhp is anyones guess

it pulls as strong until the limiter - infact so much so i was contemplating upping the limiter a bit... but no not on an eta crank though nobody's broke one on here yet... and the cam is an alpina cam so i presume 268/268.

is there any good software to figure out this kind of thing?

Post Wed Apr 11, 2007 3:46 pm

Facinating thread,liam,my 2.7 seems to develop max torque a little sooner than yours,maybe at around 3000rpm. I have a 320 head with 325 cam,my research before building lead me to think that a longer duration cam would give more absolute power at the top end at the expense of torque/drivability where I could make most use of it.I have a 3.64 diff,the ability to drop into 4th at 45mph and accelerate past a line of traffic never fails to make me smile.If you can find a way to combine this with your top end grunt you will have found the holy grail!!

Post Wed Apr 11, 2007 3:53 pm

well i am gonna confirm the max torque thing as i was hasty about writing that tbh i think its earlier
as for the diff i have a long old 3.46 so i have to drop to third for overtaking as there is never much space around here so you need to get it over and done with.. , what really is ace though that i can go from 30-100 in 3rd very very quickly always satisfying - down side is 5th really only gets used 50mph and up which is rare but it makes long mororway journeys an absolute cruise.
i dont want to sacrifice much of the top end if possible but i do want to move the torque lower down.

would it be easy to mount injectors into the above inlet manifolds does anyone know?