99 replies to this topic

[Sprocket]

Thats a Jenvey throttle body

[mini93]

it is indeed, but at 35mm! with injector positioning nice bit of kit

[mini93]

well last night i emailed a few people about porting the head, slark roughly quoted me £850 and requested to see the head before definate quote could be given.
rob walker engineering in oxon quoted £120 which seems damn good, and reports from sumone i know said they are very good and everything they do exelent

[johnK]

pm me and I'll give you a quote for SC to port your head - we have done a few you know wink wink!

- throttle bodies - is there any reason you aren't running the stock BMW bodies
for your engine if you are sticking with ITB's to supercharge through?

cheers

JK

[mini93]

you have pm

not running the bmw throttle bodies because basicly i didnt get them when i bought the head...and they look soo nice n shiney!!! lol ok maybe not such a good reason but on the site they said there suitable for forced induction

and sorry didnt get the bit about ITB i dont always get the abreviations

thanks

David.

[wolfys_mini]

indiviual throttle bodies

[mini93]

thankies wolfy man lol

yeah, i didnt get throttle bodies and hoping if neccesary a wider range of inectors...maybe lol not somthing iv looked into much yet, im still hoping to stick in a standard front. between the head and body i guestimated about 5 inch of clearence, morspeed to the manifold for the 16v head which itilizes weber flange which is what those jenvy throttle bodies use which i emailed them about being 1inch long and then bodies 35mm so the rest of the space infront can be for plenum

but before i buy anything like manifolds im gona have to read up on how it will effect torque theres no point making sure to keep in standard front and having a manifold which isnt going to benifit the enigne or moving the power band to a point which is unusuable...which im sure in the end im going to have to get custom manifold made up sticking out the round nose or just buy a clubby front

[mini93]

aah its kinda annoying me, i know im not going to be settled on anything for a while but the whole thing about induction lengths is annoying..not quite sure what i want from it really...what it will rev to where id like max torque to be

basicly i want anybody to talk to me, who can talk me through how long my inlet manifold should be, on the DTA site a read that its the distance from the rampipe enterence centre to the centre of the valve that in a way affects what it revs to

What is the correct overall system length?
Induction length is one of the most important aspects of fuelling performance engines. In our experience an under-length system is the greatest cause of disapointment, with loss of up to 1/3 of power potential. There are a number of good books on the subject and the serious developer is referred to these and, in particular, dyno trials. A guide figure, from the face of the trumpet to the centre of the valve head is 350mm for a 9,000 RPM engine. Other RPM are proportional, i.e. for 18,000 RPM the figure is ca 175mm.
The induction system is part of a resonant whole - from trumpet to exhaust outlet - and the ideal length is heavily influenced by the other components.

the engine is going to be stroked so its not going to be such a high rever right??(correct me if im wrong) well id still like max torque to be high up in the rev range but to a point it is still usable. Going by that the further away i have the throttle from the head the higher its going to rev

if anyone could also give pointers to what else i should think about when deciding on lengths, also the length of the throttle bodie aswell (theres longer one on the site aswell) then theres positioning of the injector which is changable with different bodies

in my head i keep thinking stuff up but then i keep thinking "well thats gona be different because its forced induction"
the stuff on the site is that actualy relivent to me because i want to run supercharger??


so knoted up!!! i need to sleep

[JetBLICK]

I cant comment on the inlet lengths, its something i know little about... tho that website where you got that sounds like interesting reading, where did you find that?

You know where you say 'its stroked so its not going to be a high revver' well thats not strictly true. You can make any engine rev, it'll just be harder to do so with a stroker, as you probly know (being an engineering type), the forces involved are greater. I think the reason its less commen to see that tho is because its simply not worth it. This brings me on to your comment of where peak torque comes in. I cant understand why you would want to have it come in so high, unless your plan was infact to try and get a very flat torque curve, which just peaks near the end. What i was gonna say tho was i cant understand why you would want that, surely a better idea would be to make the best use of what the engine will give you, i.e. you've got a stroker, 16valve head, and your using a 'charger, all that (imo) points to a motor that will make great torque from get-go and pull hard all the way to the top of the rev range. After you've figured out that, you can make up for any lack in revs by using a lower final drive ratio which will up your terminal speed, but wont hinder your acceleration due to the immense torque you should have. Having said that tho, with a charger and a 16v head i doubt very much that you'll have any problems making good revs either.

To give another example, the opposite, on a short stroker, you can capitalize on its willingness to rev, due to the fact theres less stress and movement on the internals. On a short stroker peak torque doesnt come in till late, but by using a higher final drive you can overcome the lack of it and have good acceleration, but because of the revs you can still reach a good top speed.

Oh, and by the by... dunno if you copied it wrong, but the quote u put says the 18000 rpm has 175mm distance and the 9000rpm 350mm... think your comment the wrong way round.

Dan

[mini93]

its what i was also lead to believe about the torque all the way through the rev range but having a more even torque curve is better right? i was also told that having torque higher up wil be better for track racing..except this was from sumone whos wanting a 6speed box (less %ratio drop basicly keeping in the best rev band possible)

would it in a way be better just to get longer throttle bodies (im not intierly sure how benificial this would be) and just make some nice long manifolds straighter quicker airflow this way. also injector positioning im sure the throttle bodies have intigrated positioning


hmm might be benificial for me to email the company to see what they think

oh n the information is from this site DTA- FAQ section

Edited by mini93, 12 October 2007 - 04:33 PM.

[mini13]

http://www.velocity-...calculator2.htm

[Sprocket]

I wouldnt be concerned at this point on tuned induction lengths. The power and torque you will get with the large cc, supercharger and the 16valves will be huge. I would be more concerned about getting it running and then developing it there. Unless you are chasing every little bit of possible power from the engine, i dont think the amount of though and design involved would gain you much more for your efforts.

as for the throttle boddies, it will most certainly be easier and cheeper to buy some K1100 throttle bodies, some k1100 inlet stubs and a fuel rail, its the stubs that have the injector boss in them. I bought this head as you bought it from me, the inlet stubs were not supplied.

It would also be much easier again to build a plenum and use a single throttle, Jenvey again a popular choice, if you do go the forced induction route

[johnK]

Well - for my na engines I use the BMW throttle bodies and our short ram pipes (see the website for pics/ vids of the 8v 1293 twin cam clubby) none of my engines can be classed as running short of torque either in road 8v form or full on 1380 16v form! it may have been an issue years ago when people fiddled with bits of brass and jets - not with correctly mapped ignition/fuelling though. For the money it would cost I wouldn't go for Jenveys - the cost of a set of bmw bodies would be peanuts and they never wear - flow enough air for over 165bhp in stock form for n/a and generally are made with German precision - need I say more!

JK

[Sprocket]

yeh, John, fuel injection is the way to go

Any one seen this yet? Looks an interesting site thats just started up, could be usefull?

http://www.efiminis....l.com/index.php

[mini93]

been sourcing some info over at turbo minis about manifold lenghts, aparently the best to go for is an 18 inch length from the very centre of the valve end throught the cylinder head port, manifold throttle bodies all the way to the bellmouth/ram pipe what ever each person calls em
to fit the full 18 inch lenght into the engine bay im going to have to lean the engine back a tiny bit, and carefully sculpture the manifold, and even after all that im gona have to get a clubman front end to squeeze it all in behind

as for plenum design, well the best shape is a sort of conicle shape. pipe from the supercharger feeding one side of the plenum it will then taper down towards the last cylinder, it should allow the equil pressure across each bellmouth

the one on the right is kinda what i want to go for (ignore the fact thats for a 6 cyl' engine)

the type of supercharger id like is vortech, having a bit of a wonder about the supercharger size to match the engine size, they do a V9 which seems the best suited so far

The V-9 Series is ideal for applications where space around the engine is a consideration, as with GM F-Body and Sport Compact vehicles. Designed for engines ranging in size from 1.2L to 6.0L, the V-9 features our AirAssist/Power Drain lubrication system, exclusive D-port volute for improved efficiency and a V-band volute clamp for easy under-hood packaging.

A compact supercharger designed for high flow in a compact package

* Fits engines up to 575 horsepower
* Maximum airflow: 800 CFM
* Maximum boost pressure: 20 PSI
* Absolute maximum impeller speed: 65,000 RPM
* Adiabatic efficiency: 72%
* Available with straight discharge and clockwise rotation
* Part numbers below do not include drive pulley
* 7.836" Wide, 9.904" Tall, 5.391" Deep (not including input shaft)

all for a price of about.... one grand! for just the unit


i have bought stuff tho i finaly have the rollcage i wanted. its a bolt in cage but im going to be welding it to the shell and stitch the shell at the "A" and "B" pillers, then aditional suports shall be welded into place. need to get cr*p out the inside of the mini to BOSH the cage in tho. i want to start with the project in a major way and iv yet to get the head "worked" yet


hope yall kept up with my ramblings