Roof chopped BMW mini cooper S

[SamT]

ahhhh i got the same charger as you m@tt, i was planning on getting some pulleys made up, but the bearings an issue now. Didnt realise that, havent pulled mine apart yet!!

What you guys using for a bypass? I was thinking of just using one off the mini cooper s.

rkde do you know how much these cost??

And are you both putting the throttle body infront of the charger??

 

[rkde]

With displacement pumps you have to put the throttle before the blower. The mini bypass valve is OK and costs about £50 new from the dealer. I am going to use a normal recirc bypass valve as used on many turbo setups, thats what I have done in the past and it worked fine.

To get around the bearing issue I am making a modification to the housing and will tig weld a housing for the new bearing and then will turn a new pulley for the outside.

 

[SamT]

With displacement pumps you have to put the throttle before the blower. The mini bypass valve is OK and costs about £50 new from the dealer. I am going to use a normal recirc bypass valve as used on many turbo setups, thats what I have done in the past and it worked fine.

To get around the bearing issue I am making a modification to the housing and will tig weld a housing for the new bearing and then will turn a new pulley for the outside.

Sweet, sounds good

Think i'll pop down the mini dealer this week see if i can order a bypass valve, unless youve got any spare you wana sell??

What s/c are you using??

 

[rkde]

I am using a twin screw blower lysholm 1200AX. I sold my last bypass valve last week.

Some pictures from my celica build, there is a spelling mistake but thats how a displacement pump should be arranged

 

[SamT]

I am using a twin screw blower lysholm 1200AX. I sold my last bypass valve last week.

Some pictures from my celica build, there is a spelling mistake but thats how a displacement pump should be arranged

oh wicked, lysholm is out of my budget range lol

Yeh thats how my setup will be running like too, you see alot of the vw guys who dont move the t/b when upgrading to the eaton. i dnt think they realise they are designed to be run under vacuum

 

[rkde]

Well I had a friend who did a supra and did the throttle after the blower, even after my advice, what happened? well when he revved it the car continued to rev on its own up to the limit

Don't use silicon pipe bends like in that photo, I had to change to mandrel because under vacuum the pipes crushed in! that picture was a mock up only

They are not designed to run under vacuum, The roots blower is a displacement pump therefore created a - pressure before the blower which is why you have the bypass valve to overcome the vacuum in the blower inlet, under normal driving conditions there is a vacuum after the blower to the engine which is caused by the pistons and the open bypass valve, when you open the throttle the blower turns faster causing a + pressure which then closes the bypass valve and your boosting. You must keep the pipe work short to the engine from the blower or you will loose pressure (the more area you have the less pressure you will achieve)

 

[SamT]

ah right i see, im going to be usig a fmi though, this is going to make my pipe work long, i guess its just a compromise.

 

[rkde]

Yep it will loose quite a lot of boost with a FMIC probably as much and up to 5psi meaning with an m45 you will only achieve 3-6psi at max rpm. ideally a water cooler PWR barrel and keeping things direct is the best for power. I also ran without an intercooler on the build and found that running with the IC made such boost losses that I actually I had more power without it and just suffered temp clipping

 

[M@tt]

Thats really interesting regarding the TB position , I hadn't yet decided on where to out mine although I was erring on after the blower as i m using the standard inlet plenum on mine with shortened runners, and the TB is bolted to the end of it as standard.

This is a pic of my mates 205 mi16 supercharged with an m45. He fitted the throttle body after the blower and so far I don't believe he's had any problems with it.

It's running an intercooler as well and it made 240bhp up from 160bhp as standard on that engine, so not too bad, but by the sounds of it it could make more with a bit of a redesign

 

[rkde]

Corky bell (book) says you will make more power the other way around, I will see if I can get a quote about it from the book

 

[Will1983]

have you thought of using a twin throttle arrangement? one before and another after the blower..

check out this thread from my usually forum MX5Nutz

 

[rkde]

here is my euro bumper in the making

So what is the Euro bumper? well its part of a whole kit which will include skirts and a front bumper and then later a wide arch kit to complement it.
The rear bumper is a cooper pre-facelift with the chrome section removed and them smoothed flat, this is complimented by a moulded in set of GP style rear skirts and lip, then the whole bumper goes off to be moulded as a one piece so its smooth bumper ready for paint and fitting.

Chrome and middle removed

GP side on

GP bottom section on

Bumper so far

Next the bumper will have the middle filled and smoothed and the arch and rear lip will be smoothed together to remove any joins

Also managed to fit my light weight bonnet in place

 

[rkde]

Been a busy little day out in the shed! Text and everything in my blog as per usual on my sig - for those who want just pictures here you go

The engine is now stripped ready for the work to commence...

 

[the snooper]

watch you dont mix up those bearing caps they are machined as pairs, i knew some one who did that and the wondered why his crank was so tight

 

[rkde]

No need to worry non of it is going back in the car, all new rods, pistons, and bearings. Maybe even a crank if I can find a pocket deep enough!

They are in and order at the moment and will but put back on the rods, thanks for the advice though ~ If I didn't know I could have made a big mistake - glad I do know though

 

[the snooper]

are you getting the engined bored out next size up or are you looking to increase engine size

 

[brightspark]

when its ready for rebuild take it in and get the whole lot balanced including the clutch and flywheel its well worth doing for a smooth running engine and u can rev the b...s out of it without blowing it up

 

[rkde]

I am torn at the moment with the next step, I will either have the block honed and bored then go up one size though still after market forged items. Or I will be stroking the block to a 1.8 / 2.0

If I go up more than 0.20 on the bore I am going to get the block sleeved as I will be running much higher boost than it was designed for.

I will be taking the block to Geoff Dod (autosprint) who is an engine builder by me, I will balance this engine, the last one did rattle a lot at the flywheel, partly because I went from a duel mass to a single.

I now need to wait and see what 2011 will do with my company. If I do well then the engine will have a lot spent on it...

 

[davenport]

i was over at a company called TDF in kimbolton before xmas and they were then mapping a customers mini, the S/c unit had been binned and a turbo fitted in its place.. i`m sure it was over 300bhp...

i don`t know many details but they guy intends to use it in time attack so might be able to find out more on it...

or call Matt@ tdf and discuss it.. i know by using his own ECU he was able to retain all of the factory electronics AND add more features via his ecu...




as for the build- i love it.. i wont lie, when i saw your idea i immediatly thought "here we go, another dreamer" but full credit for making me eat those words, it looks great, hats off to you buddy...

 

[rkde]

Cheers, Its been a dream for a long time. I will get there eventually... The hardest part is I want to do everything myself, I don't want anyone to do the work, I want to put all my tuning, machining skills together and build it myself. The hardest part for me will be the mapping. Just want the roll cage to turn up.

I will be binning the stock ecu as the mapping is limited, the car you saw must be either Lee's (was black last time I saw it) or Richard's (grey with GP spoiler) also I think 1320 are running a turbo (red) as they are the only 3 I know in time attack and a turbo. I did think about the turbo but I love superchargers.
The minis can run silly power with very little work.

I produce light weight panels, bonnets, boots, etc for the mini and extra light units for time attack cars. All good fun.