Hi all

Im contemplating a turbo duratec engine and have a couple of questions>

What power and RRM is the standard crank good for?
After changing to forged rods and pistons on standard compression what would be a safe max boost?
For 300-350BHP would i need to upgrade the valve train iff so which parts?
any other upgrades that would be required / recomended?

cheers tilly

Have a look at flak monkeys thread for everything you need to supercharge a duratec:
http://www.locostbuilders.co.uk/forum/9/viewthread.php?tid=109801

Regards
Hugh

Std crank is ok to 9000rpm - power is mostly irrelevant

Turbo boost is very different to supercharger boost. Where you can easily get away with 1 bar boost from a supercharger on std compression, I would be hesistant to run much more than 0.7 bar with a turbo before you have knock issues.

The problem is you will have full boost from ~3000rpm with a turbo, so you are far more likely to have knock problems.

If you are fitting forged pistons, 8:1 CR ones are readily available, so I would fit those and then run 1 bar of boost. You should make 330-350bhp under 7000rpm with that set up.

FWIW my supercharged duratec running 9 psi with 10:1 CR and fast road cams made 291bhp and 242lbft @ 6300rpm.

Beauty of forced induction is that you dont need to rev it to get the power.

In such light cars superchargers are far more suited - but then I am biased

David,

I don't quite understand your comments on superchargers and boost.

For a roots type supercharger surely the boost is independent of RPM?

Could you explain for me, I'd like to become educated.

Matt

Rootes superchargers are different again. Apologies, my comments above are related to centrifugal superchagers rather than positive displacement superchargers such as the Rootes ones.

Rootes boost curves are very similar to a turbo boost curve. They arent linear at all, and tend to drop off at higher rpm too. They also are much less efficient and pump a lot more heat into the inlet charge. All these things combine to mean the compression ratio required for the same boost on a rootes charger would be similar to the same boost in a turbo application.

Centrifugal superchargers typically give a very linear boost curve and it will continue to climb right up to the rev limiter if the pulley is sized correctly.

This is the plot from my dyno run, the blue line at the bottom is the boost curve:


01-10-10 dyno result

All that said, rootes chargers are arguably better on the street as they build boost quicker. But you'll need to run a lower CR to avoid det so simulataneously loose some low down driveability - swings and roundabouts.

A lot of what you can get away with CR wise is very dependant on engine design. The duratec is very knock resistant as it happens.

My recommendations would be 8:1 for turbo or Rootes/PD superchargers for up to 1.5 bar boost and 10:1 or 10.8:1 for centrifugal chargers up to 1.25 bar of boost.

[Edited on 11/11/10 by flak monkey]

Very useful, thanks,


Matt

p.s. also another opportunity to show your power curve!

Thanks very much all espeshly flack monkey, i have read your project thread and have come to the conclushion that the folowing mods are nessasery

Low comp pistons (forged) 8:1
Forged Con Rods
ARP head studs
uprated valve springs, retainers and seats does anybody now the standard valve springs spring rate???

any other internal upgrades???

cheers

Mild road cams work well with superchargers, I am not sure how they work with turbos - mild ones should be very good in theory. There are a couple of duratec turbo specific cam grinds - however I would be tempted to stick with the std cams or fit mild road (racetech 210 spec).

As a minimum:

Forged rods and pistons. ARP studs in rods.
ARP main studs
ARP head studs
Std head gasket seems ok with sensible boost
Heavy duty big end bearings
Fast road springs (double or single - doesnt really matter)

For 350bhp I would run a 7.25" race type twin plate clutch too and therfore you would need a steel flywheel too. I would expect even the clutch I used to slip with the torque surge you would expect when it came on boost with a turbo. The clutch I used is the highest spec available to fit the ST150 flywheel (rated to 220lbft - although it was OK at 240lbft). All the research I did lead to dead ends for any clutches with higher specs which were suitable.

David

I'd second that centifugal supercharger is better for most apps.
What do you plan to use the car for?

Doesn't Mazda already make a Duratec turbo for thier MPS engined cars? Would be a good starting point if you could find one.

ATB Dan.

i think the point made about increased drive ability with a supercharger rarther than a turbo is a good one
what do you think about a CR of 9:1 and higher boost

tilly

quote:

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Originally posted by tilly819
i think the point made about increased drive ability with a supercharger rarther than a turbo is a good one
what do you think about a CR of 9:1 and higher boost

tilly

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quote:

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Originally posted by scutter
Doesn't Mazda already make a Duratec turbo for thier MPS engined cars? Would be a good starting point if you could find one.

ATB Dan.

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iv just been reading your website david very interesting stuff i must say

my one question is were about in the usa did you source your parts such as rods and pistons. i have found a few on fleebay usa

tilly

I bought through a company called Import Performance Parts who have both European and US websites, at the time it was cheaper to order through the US site and pay duty.

As others have said the 2.3MPS engine is turbo'ed from the factory, though they are relatively rare and command a reasonably high price in comparison to a std Duratec.

David

No dealings with Noble Motorsport myself but I know they supplied the engine for Striker North when they built a demonstrator with one.

Other than that if you are after a programmable ECU at some point OMEX have done a lot of forced inductio dev for Westfiled using the Duratec though mostly using the Rotrex supercharger.