engine choice
Turbo Mini Forums

Hi, i've been lurking around here for a while and must say there are some great projects going on. I've decided its time to look for a project for myself. Now I know the type of car i'd like to end up with. Basically a road legal miglia. The car is gonna be mainly used for track but with the odd show and trip to le mans etc, i'm not into trailer queens!

The big undecided part is engine. Would like it to be something a bit special but this is by no means an open cheque book project.

I think its between

Bmw 16v head conversion.

7 port head (not sure which)

Or a standard turbo set up.

Although new to minis, i'm not completely new to car projects having built several kit cars and raced in caterham academy in 2008.

I would very much appreciate your advice on these option, pros and cons. And also alternatives

thanks
Ben.

There are so many options and opinions it will be difficult to find a straight answer. For my money I would go for a SC 7 port fuel injected Turbo or a BMW k head Turbo. Both easy and driveable 200 bhp

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

Must say the sc 7 port looks fantastic and is probably the simpler conversion or am I wrong?

I think the SC head is a good path to go.

I would say the 7 port route would be easier/cheaper, in the respect that alot of standard a series turbo parts can be used. To turbo either requires a fair amount of fabrication, like plenums etc though.

Edited by matty on 22nd Jan, 2012.

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1/4mile in 13.2sec @ 111 terminal on 15psi

Not too worried about the fabrication. Have always used Bob Hall at Concept Racing who is just down the road. Anyone whos seen his work will know how good it is.

So if I go 7 port, is the sc head the one to have? I see there are a few about!

I would say yes,

all the other 7 port heads have very big ports, which can hurt the low down gas speed.

also with the SC head the fabrication will be easier as it already has inlecor pockets on the head so wou dont have to include them in the runners (mine were a PITA to get right). plus the SC head has the runners closer together so you end up with a more compact plenumn.

plus SC do the head throttle and ECU bundle, last time I looked it was £2500 ish which is pretty damn good for whats included.

Joe, would you consider running ITB's with a turbo? That's what I was planning, but most people recommend 1 big Throttle Body.

Edited by alaskanow0 on 23rd Jan, 2012.

Class C 3rd Place Avon 2011 14.18 @101mph

There is no reason not to use ITBs with a turbo. The advantage of ITBs over a singel TB is throttle response. But as this is governed by the turbo it makes more sense to stick to a single TB as it's much simpler.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

ITBs would be a rubbish idea eh Joe?

I think the main reason that a single throttle body is more popular, is that it's easier.

In the 13's at last!.. Just

Okay,

it depends what your doing really, my current setup is one throttle however I am about to change this to a set of GSXR throttles....

on my setup (minisport head) the ports are pretty large and with my injectors and cam I think the combination of low gas speed and poor spray pattern are making part throttle driving stumble and miss. I'm going to use the GSXR TB's to speed up the gas flow due to the gas speed and turbulence caused by the throttles,

also on my setup if I nail it low down it's flatter than if you ease the throttle in... on the Gixer throttles there is a secondary set of butterflys that I'm going to control (and map) from the ECU.

also I'm going to make the setup so I can change the runner length


Also Ive blown the welds clean off by plenum for a second time due to too much boost...

with the SC head the ports are nice and and it hase thhe injector holes small so multiple TB's are pretty pointless, however if you can pick up a set of bike ones cheap it may be a way of doing stuff cheaper.

Just to add ne last point about ITBs on the SC head. The ports are very close together so I think you'll struggle to get anything other than the SC TBs to fit.

Another reason that one TB is easier.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

good point Will,

the bike TB's are easy to widen, but narrowing them would probably be a pita.