3.0 8v turbo

[scam75]

I did not need the extra capacity as was never planning on running much more than 300 BHP. Plus I like to keep my original engine and engine number, hence the road I went down.

 

[PSH]

I did not need the extra capacity as was never planning on running much more than 300 BHP. Plus I like to keep my original engine and engine number, hence the road I went down.

There's a lot to be said for keeping matching numbers..

 

[blade7]

I don't get the matching numbers thing on a 944, unless it's a low mileage investment. It just doesn't matter to most buyers. And a basic 3.0 conversion is more about reducing lag than making big power.

 

[scam75]

Each to their own! I found replacing the AFM barn door with a MAF made a noticeable difference to drive ability, a bit less lag and turbo spools a bit quicker, but much of the charm of an 80's turbo car is the lag then getting pinned into your seat. I would not want to change that too much.

 

[blade7]

You wouldn't want that shove to start 500-1000 rpm earlier?

 

[scam75]

Not really tbh. It's fun the way it is.

 

[PSH]

You wouldn't want that shove to start 500-1000 rpm earlier?

Crank the duty cycle right up, makes a world of difference to the lag and engine response...just beware of boost spikes...

 

[dlknight]

Seems a bit odd to me, that owners that have to rebuild their 2.5 engine haven't sourced a 2.7 engine and 3.0 crank, and rebuilt that instead. Most of the external 2.5 parts bolt straight on, and aside from the engine code and a small bolt on the head, it would look pretty much the same.

Money?

I'd argue it is cheaper to rebuild a 2.5 engine than start increasing capacity, you'd need to source the parts and 2.7 / 3.0 parts aren't cheap, speculators sticking unknown used S2 engines on ebay for £3k+

There is one crankshaft on the bay right now for £500

I wouldn't even know where to start and what combination of parts would be needed to create a reliable 3.0 8v engine.

 

[blade7]

A 2.7 engine and a S2 crank for starters. People have successfully used machined S2/968 pistons, and Porsche Rarst rods. Add a set of turbo exhaust valves and valve springs and you'd have a basic reliable 3.0. If you couldn't find a 2.7 and S2 crank, Yanks were using an offset ground 2.5 crank, and cheap Mitsubishi spec forged rods, plus liners and JE pistons. I don't know how long the cranks lasted with a chunk ground off them, but a few were built like that. As very few people seem to be building 3.0 engines now, I'd have thought the market for the parts would be very small.

 

[Eldavo]

Crank the duty cycle right up, makes a world of difference to the lag and engine response...just beware of boost spikes...

Well, err kind of - that’s literally how a boost solenoid works: apply 100% duty to hold it closed and as boost then builds you lower duty cycle to keep it precisely at the level you want it. With an Apexi AVC-R like yours it takes about an hour of understanding what you’re doing and why, with modern PID systems built into standalones and modern units it does exactly that for you.

I’ve lost count of the number of times I’ve said that a properly setup AVC-R will spool up and boost exactly as you have it set but won’t boost spike subsequently. But as Keanu Reeves said - you get to a point where it’s not worth your time to argue and if someone says one plus one is five you just smile and agree.

 

[PSH]

Err...if you reread what I said and how I said it you should see it was very muvh a tongue in cheek comment.. the Apexi is an amazing bit of kit, IMHO still not bettered when talking EBC's. Mine learnt a long time ago how I like things.

 

[blade7]

Err...if you reread what I said and how I said it you should see it was very muvh a tongue in cheek comment.. the Apexi is an amazing bit of kit, IMHO still not bettered when talking EBC's. Mine learnt a long time ago how I like things.

I could be mistaken, but I think Eldavo may have ditched something similar, in order to run the boost control built into his VEMS.

 

[PSH]

I could be mistaken, but I think Eldavo may have ditched something similar, in order to run the boost control built into his VEMS.

I believe you are correct sir ..

 

[blade7]

Not a 3.0 but I have been a passenger on track in a 2.8 long stroke 951, Andrew Sweetenham's car to be precise. That car was fun, blitzed everything one PCGB session at Castle Coombe circuit many moons ago with its 422bhp. ...

Was that the white turbo that went off to Ireland Pete, I wonder if it's still running. I think the Irish owner posted on here a few years ago.

 

[PSH]

Was that the white turbo that went off to Ireland Pete, I wonder if it's still running. I think the Irish owner posted on here a few years ago.

It sure was...great car a good driver....he proved that by setting Pole at Silvetstone in his red race prepared 951 in the Porsche Cup championship before the older cars were later banned. Just too fast for the GT3's of the day...