Boost and cooling
Turbo Mini Forums

I,m the loony with the turbo A35 (ask your Dad)
Its now running reliably with a points set up and 26 degrees total advance,plus vacuum and runs just a little hotter than N/A, using only 6lbs boost.Not sure how much further I can go without running into detonation which usually announces itself with a large plume of blue smoke at the rear.The car gets very hot very quickly in traffic, but the electric fan seems to hold it.Is it usual to run higher coolant temps with the boost or should I worry ?.Should I be trying more advance?.Is there a recognised compromise to reducing turbo lag?.Did 300 miles last weekend, a lot of it at 80mph plus on the A1 and it still wants to go, but acceleration out of corners and roundabouts is frustrating when it drops off boost.Maybe the upcoming intercooler (Punto GT) and a bit more boost will help ?.

24 deg total advance is best

use a 74 deg stat and no other

Hi,
Mapped ignition would be the way to go.
More precise control and you can throw a load of advance at it off boost to get it spooled up quicker
Cheers,
Gavin :)

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If the engine heats up quickly and get hot when in traffic then I would say that a bigger rad is needed. Fine if the fan is keeping it just cool enough, but wait for a hot day and you will be in trouble. The intercooler will do nothing for engine temps.

I agree with gavin though, mapped ignition is the only way to go with boosted engines.

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And as for boost threshold problems, this is allrelated to your turbo specification and compression ratio.

I assume that you are using the standard Metro T3? if so, chuck this in the bin and replace it with a more modern (or at least better matched/smaller) turbo.

If low boost threshold is your priority, then a T2 off a Renault 5Gt turbo is a popular choice. There is plenty of other choice of modern GT series turbos too, the GT17 is currently flavour of the month, but a GT15 could also be a good choice.

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

Overheating in traffic means bad cooling or too much advance+lean low loads. This usually ends with autoignition, the engine keeps on running after the ignition is switched off.

The engine has a total thermal efficiency of 30-35%, the rest must be evacuated somewhere. ~30% is evacuated through the cooling system.
The more HP you want, the more you must evacuate.

std 998 A+, g295, MD266, RHF4, 109hp @0.8bar/5400rpm

Many thanks for your contributions.Mapped ignition and a different turbo are not viable options for me, at the moment due to a lack of toy allowance.Will persevere with adjustments,particularly less advance and intercooler,together with more boost.Ran it up through the gears today at8lbs and it seems to survive OK.Definitely spools up quicker with less advance and a progressive throttle opening, rather than just flooring it.

lack of toy allowance LOL.