Given that my MY98 UK turbo has a TD04, and that it can't hold boost up to the red-line, would I be right in thinking that no matter what else is changed, e.g. intercooler, injectors, FCD + more boost on Dawes, that the 'peak' bhp ( and effectively the power in the top rev band) will not increase ?

Obviously, increasing boost via dawes (already fitted, but with factory fc) or improving the efficiency of the intercooler (thereby reducing the charge temp) will give more power in the lower/mid range, where the turbo has not reached its peak yet.

If this is the case, what is a good turbo replacement ? I've seen the arguments for and against a remap with a TD05, but I assume that this is 'simply' that the ECU map does not 'know' that the new turbo can give more boost, so there is a danger of 'leaning off' as the turbo reaches the point where the td04 gave out and not enough fuel is supplied (though I'd have thought this could be seen with an AFR)...

Does anyone do a turbo that is better than td04, but not as severe as the td05 ?

Thanks,

Mark


PS _ Feel free to correct me if this is technically '****' !

 

Its for reliability reasons that your turbo doesnt boost fully all the way to the red line, it would put too much strain on the internals of the engine and things would go bang.
(Speak to John Banks as he can explain things about this subject better).
There are plenty of different types of turbos out there though that you can change to, the fact is, is that your still going to be limited by the engine/clutch/geabox as to how much power you can put though them.
The TD04 isnt that bad a turbo, its not exactly the best one out there but it is very reliable, you could choose the likes of the VF series turbo, then you would need to have your car remapped to run one of these (or any different to the one your currently running now).

Tony

 

VF35 would be a nice compromise.

Think about airflow rather than boost.

 

John, I hear you - particularly as I've tuned A series mini engines to ~120bhp with only normally aspirated 1380cc.....

A better flowing engine would be much less strained (bhp to bhp) than a fully boosted badly breathing one :

I'm not sure where to look for flow next, as I've de-catted, panel filtered, de-resonated and am using Samco hoses on the IC. I'm guessing that heads/valves are expensive with marginal gains, as its a modern 16valver anyhow and I'm not really tempted to go 'cammy' (my last mini wouldn't run under 1800 revs, but redlined at 10000)


Any advice ?

Thanks,

Mark

PS _ John, are you saying that a v35 would give better flow ? - If not, and flow can be found elsewhere, I could stick to the TD04, otherwise, do I need the re-map ?

[Edited by markwild - 1/16/2004 7:39:49 PM]