Spot the difference!

XantiaMan · Unread post by **XantiaMan** » 06 Oct 2009, 12:18

I got my old Transit turbocharger out to compare the difference between it, and the turbo fitted to the Activa. Taken with my Blackberry so not very good quality i am afraid.

For a while now i have been banging on about how poor the standard turbo is for bhp, and the reason why this engine 'appears' to be difficult to get to 200bhp. The Activa's compressor wheel is about the same size as the Transits! Great for quick spool and torque/smoothness, but completely useless for anything else.

To give you an idea of what a decent turbo should look like, check out my Maestro's turbocharger.

The one on the right is a 60 trim Cosworth, the left is the original 45 Trim.

I am hoping to get a wheel of similar size fitted to the Activa turbocharger. Its not rocket science to tell it will make a significant difference to top end power let alone the extra torque it will gain in mid range. And it will still be on low boost

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KP · Unread post by KP » 06 Oct 2009, 12:33

Are you still hoping to keep some low down torque Gareth as keeping the exhaust turbine the same should help keep the spin up down a fair bit unless it wouldn't be able to balance correctly due to the wieght differential maybe??

Looks nice and meaty

This is the last big turbo i handled

http://www.wholesale-turbos-direct.com/ ... &sa=G&um=1

Unread post by **CitroJim** » 06 Oct 2009, 12:35

This is going to be VERY interesting Gareth, to see what difference a bigger turbo will make

XantiaMan · Unread post by **XantiaMan** » 06 Oct 2009, 15:54

KP wrote:Are you still hoping to keep some low down torque Gareth as keeping the exhaust turbine the same should help keep the spin up down a fair bit unless it wouldn't be able to balance correctly due to the wieght differential maybe??

Looks nice and meaty

I am expecting the boost threshold to be very similar, because it retains the exhaust side as original this has more of an impact on spool time. Keeping the A/R of the housing and same turbine wheel will retain a lot of the original characteristics and the bigger compressor will provide better flow once 'on boost. I would be shocked if the boost came in 300rpm higher, based on my previous experience. The Maestro came on boost exactly the same time before and after the bigger turbo!

Decat will also help but thats going to wait until the swop and clutch, MOT next month (the deadline) and road tax end of this month.

ACTIVE8 · Unread post by **ACTIVE8** » 08 Oct 2009, 22:56

CitroJim wrote:This is going to be VERY interesting Gareth, to see what difference a bigger turbo will make

I agree so I will also be looking forward to see the results.

addo · Unread post by **addo** » 09 Oct 2009, 11:27

Don't get confused by all that technical guff.

REAL power is made by a stripped out interior, a 4" exhaust tip, fancy stickers and of course blue coloured hoses in the engine bay. Burberry seat belt shoulder pads optional.

Sid_the_Squid · Unread post by **Sid_the_Squid** » 09 Oct 2009, 13:26

Your so right addo, but don't forget the 'sick' rims, and the 'tight' bodykit.

Like this little gem.

That will be mad wikkid fast.

gotta love the barryboys

Xaccers · Unread post by **Xaccers** » 09 Oct 2009, 14:23

That reminds me of the fiat seicento I saw on the way to Jim's last night, twin exhausts, and a bodykit giving it the appearance of round rear lights.
In need of a serious wash though.

KP · Unread post by KP » 09 Oct 2009, 15:11

are you on about these barry boys???

http://www.barryboys.com/

or these ones??

http://www.barryboys.co.uk/mx/

Sid_the_Squid · Unread post by **Sid_the_Squid** » 09 Oct 2009, 15:34

The latter one KP, don't know the first bunch.

ACTIVE8 · Unread post by **ACTIVE8** » 10 Oct 2009, 12:31

Front tyre wheel arch to tyre clearance looks kak I.E. way toooo large in it!

Front spoiler....so necessary on a 1.0 Corsa.....splitter

good for shoveling snow etc.

Four tail pipes

this thing is a sheep in wolfs clothing!

The driver leans out at the lights and says "Come on (like the advert) if you think you are slow enough!"

ACTIVE8 · Unread post by **ACTIVE8** » 10 Oct 2009, 16:45

This reminds me of an advert from the past!

They should bring back an up to date version of this, with another product.

red_dwarfers · Unread post by **red_dwarfers** » 10 Oct 2009, 18:06

ACTIVE8 wrote:This reminds me of an advert from the past!

They should bring back an up to date version of this, with another product.

'Six appeal'....oh dear.....

XantiaMan · Unread post by **XantiaMan** » 10 Oct 2009, 19:29

Right i've had figures back today on the original turbochargers spec, namely the compressor wheel which is the subject of this upgrade.

I was a bit shocked to here that the wheel is virtually the same size as a R5 GTT!

Here are the measurements.

37 mm inlet 51.4 exducer

I need to work out from these figures what the 'trim' is but lets just say, there is a reason why they only run up to 9psi standard and increasing boost does not offer huge improvements.

I am looking at having a 'Rover' hybrid, which will mean the slightly larger compressour housing from a Rover T16 fitted onto my current turbocharger core, retaining the turbine side as original.

The Rover was a 200bhp engine straight out of the box and would quite happily run more boost without going out of its compressor map but in that installation, the intercooler was very small.

The Rover T25 Turbo is 43.5 inducer and 54 exducer. This is a worthwhile upgrade with virtually no increase in lag. In the Rover installation, they would hit 11-12psi by 2100rpm which was the same time as my existing turbo and should therefore be pretty similar.

Another benefit is the Rover housing has a built in recirculating dump valve, i will have to check space first but its very handy to have.

Cost at the moment will be around £120 with a new gapless oil seal and rebalanced. He said the turbo was like new otherwise 8)

KP · Unread post by KP » 10 Oct 2009, 20:48

That will be why we get boost so low down.

The rover turbo or tomcat as its known in those circles was starting out as an upgrade just as i was buying my first R5 GTT.

It was dead easy to do. Loosen the bolts, take off the exhaust housing and put on the original R5 GTT housing and rotate them both as required to fit, Lock them up and fit onto the car. Life was much easier as it was to the side of the cylinder head instead of down the back of the block on the Activa..

If it was anything like the difference i got when i swapped them on my R5 then it will definately give you some extra shove.....