Boost vs rpm with t3
Turbo Mini Forums

I have finally got my 1st turbo charged mini on the road following an 8 year build!

I have it insured and it passed the mot yesterday. I need to sort the tax out, get the wheel alignment sorted and then get the engine set up on the roiling road.

The basic spec for now is a turbo’d metro engine, aprox 9.25 compression ratio, intercooled, I plan to run up to 10 psi boost.

I am running megajolt, t3 turbo, and a cossie actuator. I have the ‘basic’ 1300 a series map loaded to the megajolt that was kindly shared on this site some time ago.
Im running a 2.9 final drive on 13s.

At the moment the engine idle is set a little quick, the fueling is a little rich until I can get it over to the rollers. Apart from the wheel alignment centre, the rolling road is the next trip it will be going on.
With this final drive/wheel setup where should the turbo start to boost? I put my foot down slightly on the way back from the mot just to check that It was boosing up, the boost gauge showed around 3-4 psi at around 4000rpm.

Does this sound about right? I have never driven or been in a turbo a series before so not sure what to expect boost wise and when. As im using a different actuator I set the preload just off the half hole setting so that it didn’t overboost.

So really im looking for reassurance that what I have at the moment is either right (which is great), or wrong, so that I can look into it before I take it to the rolling road. I don’t fancy sticking my hand down the back of the turbo to fiddle with the actuator after it has been driven there!

Any input much appreciated, cheers, dan

Sounds about right, I used to get a couple of psi at about 3500rpm, hold for a second then used to build boost straight away, 18psi just a tad before 4k.

Audi s4 b5 - 470bhp & 486ft lbs

On 30th Apr, 2012 Brett said:
yeah stick the bit in and give it a wobble

thanks for the speedy reply. and for the reassurance. i dont want to take it on a wasted trip to the rollers if there is anything that i can do to make it right now.

it was a sureal experience driving it after 8 years i can tell you. though not much of how it is how it was back then!

i will get some pics up when i can, cheers, dan

congrats on the finished build sounds good i remember the feeling of nearly ten years finishing my build and being able to drive it for the first time now im ripping it all apart again to go turbo.

Done now needs redoing lol

sounds about right dan

with my 1380 T3 boost came in about 3000.

sounds right to me, congrats on getting it done

Yes i moved to the darkside

Instagram @jdm_brett

cheers for the advice and kind coments chaps. i will get a couple of pics up at the weekend and will post the results of the rolling road when i get that sorted. am hoping for around 90bhp at the flywheel, anything more will be a bonus! cheers, dan

A lot will depend on actual tuning, and of course actuator and actuator plumbing. As well as whatever pre-load ( if any ) you have on the actuator flap.

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

cheers, theres a quick pic of i just after i get it back from the mot station. just got a few more bits to sort now.

dan