11 replies to this topic

[Oldskoolbaby]

At the moment im not sure whether to mid engine my next project or twin it.

Thing is, if I twin it, I really want two turbo'd 1000s. (Trust me this will be cheaper than the first option. A pretty much besboke engine)

I was thinking of modding them so they rev to about 9000rpm and fitting a T3 to each one. Ive never turbo'd an A seires before but I was thinking that if I raised the rpm they could take, I could then spool the turbos up.
Im really aiming for something like Carle Austins pure race car.

I know this all sounds extreme but any help will be a big hand.

[Bungle]

a 970 cc will rev more as its a short stroke motor

[Oldskoolbaby]

Dont they use the 1275s block though, just with the shorter stroke?
I couldnt do it to a 998 a plus could I? Ive got to watch the boost to some extent though as they arent quite as strong as the 1275s

[Bungle]

i think its a 1275 block with short stroke crank , but people turbo 1330s so should be all right

[Oldskoolbaby]

Thing is I do really want to use the 1000 A plus blocks. Ive got three of them ready for modding. Ive already built one of the heads up using a 12G295 and modified to accept turbo valves(slightly tuned down). I just really want to see how far I can take them: )

[Wil_h]

Well my 998 turbo runs 18psi (using a T3) but its power is all over at 6100rpm (see below)

However, this is mainly owing to the conservative cam I run as I want some low-down power, if you ran a racier cam you could get more revs. I'm not sure what sevens rev to but 9000rpm seems high for what is a long stroke engine.

[Pickup76]

In the latest mini world theres a dyno test with a mini seven and it got peak power just over 8000 rpm so you might be able to get 9000

[Jackman]

What page is that on? Just looked at the mini world and couldnt see it.

[edit] NVM was may edition not june[/edit]

[Oldskoolbaby]

Thats some mega power Wil h!! Is mighty fine for a thousand anyway.
you done much to the bottom end in terms of strengthening? I honestly didnt fink you could get that much power from a 998 at them revs with the turbo. you must have some heavy turbo lag to contend with?
Have you used the usuall 1300 turbo manifold, turbo etc?

[Wil_h]

"you done much to the bottom end in terms of strengthening?"

Standard stuff really, Centre main strap, nitrided crank. It is revs that kill engines so it dosen't need any more than that.

"you must have some heavy turbo lag to contend with?"

Well the Lag is almost zero when it is on boost. However, the boost threshold (as can be seen) is a little over 4000 rpm. It's not really a problem though as the car is so low geared. It'd be pretty rubbish as a road car.

Have you used the usuall 1300 turbo manifold, turbo etc?

Yep mainly Metty Turbo parts and an Isuzu Trooper intercooler. We use a 12G940 head too.

We've plenty of other plans fo it at the moment, a T2 being top of the list.

Wil

[Oldskoolbaby]

Why the hell dont more people turbo the 1000 then if your getting such good results? What type of pistons do you use to lower the c/r then or has the 1300 head lowerd it enough?
Do you recon theres alot more you can do to the motor in terms of sheer power cause mine will literally be solly for racing and the occasional blat on the street? Nice to see someone going down a different route to the usuall 1380 though mate.

[Wil_h]

At the moment we use pretty rubbish Heppolite pistons with a 7cc dish. We had problems with the later slipper-type pistons at high boost (they fell apart) so I wouldn't reccoment over 10psi if you are using them. Also the pistons we use are really only good upto 6500rpm. The head is slightly modified to get the CR down to about 7.3:1.

The new engine we are planning is likely to have a full injection system using a 7-port head and forged pistons. I reckon this could relieve an extra 20BHP, but still no more revs than 6500. This might be done for next season depending on funds etc.

Our car is only used on hillclimes and sprints, which is why we get away with the high boost threshold.

If you PM me your email address I'll send you a brief spec. sheet, nothing exciting but i'll give you an idea of what we have done.

Wil

P.s. Check out www.turbominis.co.uk, loads of info on turboing an a-series.