turbos and high revs
Turbo Mini Forums

youy did John, and you,stevie and everyone else that has suggested the same are nodoubt correct,BUT, as i said im stuck with the gearing i have , Will has just hinted at those that dont know why.
so i have to have a wide and high rev range, i see it as no problem at all,
Stevie ,i am not forcing the engines to rev as high as 9k, they do it quite freely,lol. i never had a broken engine in 14 years of running them to these revs,
i am already using 3.44s with a big tyre[for 10" anyway] i'll bet its not much less of a rolling radius than Will and Bens ,maybe 3-4 % down , but not much .
i have had probs at the last meeting with launching but iv'e yet to diagnose this ,[hopefully find out on friday].

but in general my launches are very good, as low as 1.5s, but usually 1.6 to 1.7 60fts.
i was just exploring the possibilities of going high tech with turbos,

but i'm abit worried about all the extra weight i'd be putting into the car,my calcs say it weighs 580kgs ish at the minute, and i'd like toi keep it under 600 if i can,

but 2 turbos plus all the associated gubbings will push it well over i'm sure,

the top and bottom of it is i just dont know what to do in reality,


carl

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

simple , run the ex from front motor backwards , ex from back motor forwards , have them meet at the back seat well and stuff them into a big turbo capable of 500 bhp outlet to ice water intercooler box then split to the two engines ,doddle.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

I dont understand...

Why cant you just fit taller diffs ??

I know that with the 3.1, and my 13" wheels I was crossing the line at 101mph in 3rd gear, prob somwhere around 7-7500rpm.
4th gear would extend that to circa 140+.

At 9000rpm, it would be mental if it could ever pull it.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

you can't get lsd into any diffs taller than 3.44, without a lot of machining.

carl

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

you can't get lsd into any diffs taller than 3.44, without a lot of machining.

carl

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

I'd also be wary of blowing the diff off the casing - the lower the FD, the more likely this is; especially on a rear-drive setup...

I'm suprised carl hasn't had more gearbox problems,

I remember seeing his car at the pod about 6 years ago doing sub 12's and thinking, that must be putting out 200 brake ish how is that box surviving with those slicks! even with a car that light.

to be fair in the last couple of years i've learnt a lot about how strong our boxes really are from this website (CHEERS EVERYONE!!), but if your putting 200 bhp through a box at 6000rpm it will have a considerably larger torque figure than at 9000 rpm.

Dont forget...light weight plays a big part. But the load is also spent over both boxes, not just one.

4x4 Cossie drivetrain, is generally weaker than the 2wd variant.
Subarus are the same ( older models anyway )

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

thats true, didn't think of that, i guess for most of the time you can literally assume the care is half the weight, although ontake off i guess the rear engine will see more like 3/4 of the load.

well that is ball park, say +/- 25%

i'm just going to bump this asm a reminder to some folk who arn,t returning correspondence,lol.


carl

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

Carl,

I've been think about this for a while and with regard to gearing I can't thing of many options, but here I my best two (well only two):

Do you need the LSDs? I know a lot of the top class D cars at Avon were only running open diffs, could you get by with a couple of cross pin diffs as this would allow you run a higher final drive? I'm sure you've already considered this as you don't buy two LSDs for the sake of it.

What ratio of drops are you using? I'm sure I came across a set of 1.1 overdrive drops the other day as opposed to the standard under drive drops that most people use. By my simplistic maths 1.1 over drive drops would take you FD from 3.4 to about 3.1

As for weight of the turbo and associated bits.

I can appreciate your need to keep the weight down, by my crude math I reckon for every kg of weight that goes on your car you need to find around a foot pound of torque to maintain the status quot.

After weighting a few bits I reckon you can stay under 600kg, but only just.

My T3 Turbo & Cast Manifold & Elbow weigh about 12 kg by comparison my T2 & Cast Elbow (no manifold fitted at the moment) weigh only 5kg, I realise that is is a smaller turbo but it should give you some idea of the weight you can save by going for a lighter manifold & elbow.

My carb / plenum / inlet manifold & dump valve combo weigh in at about 4kg, I'm not sure how much your Webers and manifolds weigh but I would have though they are about the same if any thing they might even weight a bit more (if you are really after every gram of weight saving you could always make a pair of TI dump valves).

Finally I tried to weigh an RST inter-cooler but that was to light for the scales in my workshop, so Im guessing at under a 1kg, I'm guessing that you'd want a slightly bigger inter-cooler, but I can see it weighing too much.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Just had a quick nose around and Trannex do 0.958 ratio drops, although I can't get my head round the common idler gear.

http://www.minispares.com/Article.aspx?aid=109

as its just for straight lines would a welded up rear and open front diff be worth trying?

Cheap to try, well the rear is...

Possible...

A lot of the American drag racers just use a "spool", which is basically a locked rear axle.
Although they use pretty big axles !! I'd guess a Mini would handle it safely in a straight line. Not sure what cornering characteristics it would produce though.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

yep, it'd be "interesting" on the twisty bits,

although saying that quite a few rwd rally escorts run welded diff's and still seem competative.

I pitted for 2 guys in the falken cup a few years ago they both had welded diffs and got good positions regarly, fair amount of tarmac action too.

I think its time Carl moved to the dark side of mapped ignition and FI (assuming 16v heads) as this will make your life a whole heap easier getting the motors to run clean - then you could ditch the lsd's and go for traction control on open diffs and run the gearing to suit the application.

If Carling made Mini engines
it would probably be like this one!

Mmmmm!!,
what ecu are you using John??.



carl

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

ahhh you can see the light! - mines an EFI ecu - Italian made, behind the scenes type company supply a few oems and a chunk of the F1 grid, sportscars etc. Most ecu's on the market Gotech, Emerald etc will have more than enough computing power to run your motors - though you'd need two of them! you could make them control the nos very precisely as well - split the power accurately front to rear through boost/nos timing.

If Carling made Mini engines
it would probably be like this one!

If you have 4 inlet ports per head yes .....

Every day is a school day ...........

How fast and how expensive ...... the same question...

----as mentioned two posts back - 16v heads!

If Carling made Mini engines
it would probably be like this one!

John,

now I have been told who you are all is far more clear!!!!!! Please excuse me for being dumb, still getting used to peoples names and what they do!

I have even replied to one of your posts about stuff from the SC list but have forgoten .......

Yes, the K heads will make EFI mcuh simpler. I might well be up for two ... although not in the same car.

Every day is a school day ...........

How fast and how expensive ...... the same question...

Roger - not a problem fella, I'm not sure if Carl is going 16v heads but I think he's tempted!

John

If Carling made Mini engines
it would probably be like this one!