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Juttie205

8v turbo pistons

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Juttie205

Having sourced some turbo technics parts I'm now in process of sourcing parts so I can build one of my 1.9 engines into a turbo engine.

 I know original tt pistons were machined to lower compression but not sure by how much another way I could go is use 1.6 pistons or have been told to use mi16 pistons rods and liners or do I go custom pistons.

 I am looking to build a nice strong bottom end not after running silly boost but would like between 220bhp to 250bhp. If none of the above ideas are suited I'm after any recommendations will also be running a stage 3 head and cam with larger valves.

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welshpug

1.6 pistons will give about 13-1 roughly

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petert

It won’t be 13:1, but still way too high at around 11:1. Even standard XU9J4Z pistons will be too high. Machining down some Mi16 pistons is a good option, if you can find some good ones. Alternatively buy some new turbo pistons. Iapel sell them.

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X-mo

Got some MI16 pistons in very good condition here from a "low compression" catalyst DFW engine. The compression should be 9,7:1 and a good basis for some machining.

You can PM me if you are interested.

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petert

Don't forget they're 9.7:1 with a 40cc chamber. That equates to 10.7:1 with a 34cc chamber. You'll still have a lot of machining to do, which may weaken the crown considerably.Taking 1mm off a DFW piston will only get you down to just under 10:1. Maybe a thicker head gasket too?

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allanallen

What’s the issue with the standard pistons and CR? 

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Anthony

How about using XU9JAZ / DKZ (1.9 GTi CAT 122hp) pistons or indeed the complete engine / bottom end?  That'll be 9.2:1 and a fairly simple solution for a moderately boosted 8v.

 

The original TT engines were lower compression partly because of the fairly crude fuelling and ignition control of the time, but you can safely run higher CR using a modern mappable ECU.

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wicked

Just boosting a dkz engine has been done before; it will work if you keep boost levels moderate and with proper engine management.

You could also put a 2.0 8v head on the dkz bottom end to lower the static CR a bit (larger chamber). Downside is that the bore is slightly larger. But you get bigger valves for free.

 

Note that it in the end comes down to dynamic compression; a static compression that is a bit too high can be compensated with a big cam, like on modern engines. It's not only the modern management that makes those high CR turbo engines work...

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mostormxu9

Why you dont use xu9 2c pistons with xu9 2c head or xu9j2 head?

Also xu9 ja pistons and xu9 2c head.

 

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20five_t

I thought I would post here as it's sort of related.

 

I have an old Turbo technics 1.9 setup in a 205 and also a spare  xu10jt2e complete  engine. I want to build a more powerful 8v turbo setup, but retain the 1.9 inlet manifold etc and re-use the tt exhaust manifold . 

 

Would xu10j2te bottom end work ok with xu9 (tt) head that I have and the standard 205 gti inlet. I would be combining that with TT exhaust manifold, new gt28 turbo and emerald management. (Also forged pisons and catcams turbo cam)

 

 

 

 

 

 

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