Genaral advice and guidance on what to do!
Turbo Mini Forums

Hi everyone,

I am beginning to get parts together for my turbo build but have suddenly realised I don't know what my best option is.

I have three options as far as I see it,
1. Keep my current 998 (in the car, and on the road), gather the parts, then take it off the road for a short while to assemble.
2. Buy another 998 engine, so I can spend more time sorting it out and building it up, then swap this into the car.
3. Buy a 1275 engine, build up outside of the car, then swap in.

So far I believe option 1 for minimum cost, but probably the most effort as I would have to do everything at once. Option 2 is probably my best bet, and option 3 for the most power.

I have always thought that I would not want straight cut drops due to the noise, limiting the amount of power I can run, so i'm thinking it would probably be cheaper to use a 998 rather than a 1275, as power would be limited to around 130bhp at most, and 998 engines are available for quite a bit less than the 1275. I already have a spec wrote down that should be able to achieve this sort of power from the 998. But as I don't actually know what is required to get this sort of power from a 1275, is there anyway the 1275 would work out cheaper?

By the way, I would like to keep the turbo conversion as cheap as possible (doesn't everyone? :) )

What are your opinions/ advice/ guidance on what I should do?

Cheers, Jake

2 sounds like a good bet,

dont wory about the drops, robert has been running over 200hp through std ones!! the gearset will give out around 150 hp though if abused.

if you want 130 hp go 1275, it can be done with a 998 but wont be as stressed on the larger lump.

My 1275 turbo puts out 130 bhp . Its a very basic spec and was built on a shoestring. Basically its a non mg metro bottom end which cost me 30 pounds, second hand sw5 cam that cost me 30 pounds, second hand turbo phill head that cost me around 200 pounds. I also budgeted for vernier timing gears ( not essential) new oil pump and gaskets. This was run at 10 psi of boost. Torque figgures were around 130 pounds

Hi im wanting to smack a turbo on my mini, my minis engine spec is (cant remember it all)
1380cc (thicker block walls), high compression piston rings, 7 port minisport head (not the X flow one) 4 pin diff, high lift cams, electronic ignition, aldon yellow distributer, electronic fuel pump, hif44 carb, lcb manifolds, 2 core racining radiator, also everything in the engine is strengthened, etc, etc.

I understand that you have to cut back the bulkhead to make room for the turbo and manifold but apart from a manifold that suits the turbo what exactly do i need to add a turbo to my mini? And what turbo does everyone recommend? (i've heard good things about The gt25r.
Cheers, Gaz.

use the search function all questions have been asked before

Done now needs redoing lol

Any ideas what i should search for? Cheers, Gaz.

Try searching for bulkhead box or mirage manifold or T2 T25

https://www.facebook.com/pages/Fusion-Fabri..._homepage_panel

www.fusionfabs.co.uk



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

Go and have a look in the begginers section. Why have you asked this question in someone elses thread?

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

So by the sounds of things, I could use a low spec 1275, or a higher spec 998, and both could produce this kind of power.
And its reassuring to know that the drops/ box can handle more power than I initially thought, so in that case what's to stop me going for more like 140ish.
Because I believe I would have to replace the pistons in a standard 998 due to the power, but I was expecting to have to anyway, so all I would have to do is drop the CR a bit more (maybe 8:1ish?), and run a bit more boost (17 psi?), which shouldn't be a problem as I havn't got my head machined yet, and haven't got a turbo.
And for the 1275, unless I can find a turbo lump with dished pistons, I would have to get new ones to be able to drop the CR enough surely? I don't know too much about the 1275 as most of my research has been aimed towards the 998, what kind of boost pressure would be needed for 140ish, maybe 12psi, going by welshdans figures?

And thinking about it, what pistons do people reccomend? I guess the omega cast ones are good for a 1275, as you can get them with a 10cc dish. But what about for the 998, I heard the old favourites are no longer available, so something like the calver st pistons, or 20773, ideally something with a bit of dish, as this would reduce the need for as much head work, reducing the cost :)

Cheers, Jake