54 replies to this topic

[hazpalmer14]

They are fitted to saabs, dont know which models exactly. But just look for gt1752

[nicklouse]

They are fitted to saabs, dont know which models exactly. But just look for gt1752

the 9-3 and the 9-5

[HUBBA.HUBBA]

OK cheers. Is 200hp possible with a 5 port or is 7 port better? Also carb or injection?

[HUBBA.HUBBA]

Aye, cc's don't really matter with a blower. Often less is more as it makes it easier to get the compression ratio down for the extra boost.

 

Good Q about the GT17, what models were they fitted to? 

 

Found this list, nothing on A/R or trim but the part codes might tell you.

See that's something that worries me looking at that list. As I don't know about turbo specs and models. I don't know what A/R is or what trim is. I wouldn't what to get something that was not compatible in some way

[hazpalmer14]

Loads ofor people on turbo minis have reached 200 with a 5 port and carb. Obviously in an ideal fuel injection 7 port would be better, but then there is the cost...

[Turbo Phil]

200hp is more than possible on a 5port and single SU. Leyland did it in the mid 80's with the Group A Metro Turbos. With the advances in turbo, cam and porting improvements over 30years later it should be somewhat easier.

Phil.

[Ethel]

Turbos are more complex than they appear at first glance, but they are also fairly forgiving.

 

Making power is all about consuming enough air to release the energy from the fuel in the correct combustion ratio, so the power output of a donor turbo engine is a decent indicator. There is plenty of info online about turbos, but since I mentioned it: area/radius, is simply the size of the hole the exhaust gases blow through  and how far away from the axle of the turbo it is. Spinning a paddle wheel with a garden hose is a pretty sound analogy. Trim is effectively the gearing of the compressor side (it could be used to express the characteristics of the exhaust turbine too). It's the ratio of the diameter of the impellers where the air enters expressed as a percentage of the diameter where it leaves. 

 

The main thing is you know that these specifications exist, so you can compare a turbo you find with what others have found to work well.

[HUBBA.HUBBA]

Got a price of specialist components today for the 7 port head, injection, throttle bodies, ecu, plenum. £3990 + vat seems good value considering they'll increase the chamber sizes included in the cost. Reckon I could build the lot for £5k ish keeping my existing sccr gears.
Following a recent post I read, does anyone know if 10cc cast omega's would be ok for 200hp compared to forged. I'd be water injecting too! Or just go for 18cc forged and leave the head chambers as standard?

Edited by HUBBA.HUBBA, 20 February 2017 - 07:53 PM.

[mini13]

The cast are up to the job but you might have issues getting enough volume in the sc 7 port for 10 cc pistons

[r3k1355]

I'd be water injecting too! 

 

Careful with water injection, one split/melt pipe and you'll melt the engine if you continue thrashing it.

 

Always best to have a wideband AFR gauge and knock monitor should the worst happen.

Edited by r3k1355, 21 February 2017 - 01:09 PM.

[mini13]

realistically, 200 hp is not that hard on a 5 port these days, and on a 7 port it would be a peice of cake, 180 has been done on a 998 7 port at 18 psi.

 

WI is a good option for use on the strip when you whack the boost right up, but make sure you keep the system clean or it can gum up.

[HUBBA.HUBBA]

The cast are up to the job but you might have issues getting enough volume in the sc 7 port for 10 cc pistons

. I would have some taken out of the head chamber too if I used 10cc pistons

[HUBBA.HUBBA]

realistically, 200 hp is not that hard on a 5 port these days, and on a 7 port it would be a peice of cake, 180 has been done on a 998 7 port at 18 psi.
 
WI is a good option for use on the strip when you whack the boost right up, but make sure you keep the system clean or it can gum up.

  

I'd be water injecting too!

 
Careful with water injection, one split/melt pipe and you'll melt the engine if you continue thrashing it.
 
Always best to have a wideband AFR gauge and knock monitor should the worst happen.

I've got a aem water injection on my mini at the mo which I'll transfer over to my moke. So when I build the new motor I'll get the aem kit with 'fail safe'. Which apparently covers low water level, pump failure and the system getting blocked.
So good points well made!

[matty...]

If you are going down the turbo7 port route there is no need for ITBs, you can just fit a single TB.

[MRA]

Normally just a 1293 will do it. You can over bore to what ever size you want. But you don't need the extra cc's to make the power

 

But going bigger does pull in the torque better

 

Also its my experience that the Omega cast pistons are good for at least 16psi long hard thrashes, but in reality if its a road car, your long hard thrashes will be somewhat shorter than they used to be so less of an issue, I also don't bother with a center main strap.

A 5626 gearcase is a must as is a four pin diff or better, on my first turbo Mibi in 1986 I killed one diff pin in under a week and removed the next one just before it destroyed itself in under 3 days, there is a picture of this one on here someplace...

 

Don't forget brakes and suspension upgrades, ie rose jointed tie bars and bottom arms if set up correctly will eliminate any torque steer up to about 200 at least

Edited by MRA, 17 March 2017 - 11:19 PM.