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Finally found a turbo setup for my 2.6 4G54 Sigma =)

Its a long weekend here in perth so perfect time too start my project. I currently got a turbo, dump pipe, turbo exhaust manifold, intake manifold, cross-over pipe and turbo distributor. Pics will be uploaded as build progresses.

Currently in the car is a 34ADM Weber which i plan to use and place in front of the turbo (draw through setup). I belive this was the 'stock' setup the Scorpions had?

This will be a WHOLE different learning curve for me as i have never done ANYTHING with carbys (only fuel injection). Im keeping the carby as i love the sound and its pleasing knowing i have one haha.

Hardest bit (i think) will be the oil return line which i plan on welding a fitting on the sump and plumb the return line in there.

Is there any other bits im missing or concerns i should have prior to starting? Any help or advice is more than welcome.

Wish me luck! =)

The only turbo was a GH sigma turbo scorpions wernt turbo, they had a CD 175 Stromberg?? They were a Stromberg tho.

I stand corrected =)

Just make sure that you oil return fitting in the sump is above the oil level .

and you also need some means of getting the engine oil to the turbo ..

For oil supply ill be T-ing off where the oil pressure sender is and for the return, im thinking of drilling out one of the block-off caps that are on the lower timing cover. Will there be any issues with that?

cheers.

Here is current progress-

Removed both manifolds, carby and aircon compressor.






Next i labeled all screws wires etc...

Put turbo onto the exhaust manifold and on the block and also put the intake manifold on.



Then this happened..... =/




Seems ill just be cutting it and fitting a hose in between the two metal pipes.

Ruined my day in all honesty but i got a special delivery on Friday that i had not opened so decided i would =)



Anyways need a pipe welded on to my carby flange ( 34adm weber ) and then will do the oil runs. Will keep you guys posted and as always, any help is appreciated =)

Cheers.

So the turbo manifold is either a home made job or possibly a Starion 2.6 turbo. Does it have a wastegate attatched ?

Yes, the wastegate is attached to it and then goes to the dump. I think it is off a Starion but could very well be a home job.

Cheers.

Ok, FINALLY got the car running..... Way too many problems occurred during this build due to a rubbish turbo kit i got based on the sellers description =/

Anyways, decided i was going to paint some bits to freshen things up =)

Before-

After-


Turbo had ALL seals blown and was pretty much just squirting oil out the tail pipe.
Rebuilt the turbo and all is well.





Put the car together and took it for a spin down the road, put my foot down and ALLOOOTTT of white smoke out the exhaust accompanied by a little 'POP".... Head gasket went along with a nice oversized hole in head.



Took the head to get welded and machined and all is well, once again.


Rather large pistons!


Now, the intake manifold was a fair bit warped and was not making a good seal so i had to get that also machined.
Then came the next problem, the waste-gate was JAMMED shut! I didnt notice this and as a result, the head gasket and head went. I then ran 50psi through it (compressor) to see if i could get it to open and guess what??? it didnt MOVE!

Got the sledge hammer out and waked the piston in and out for a good few hours and managed to get it loose. Had to also repair other bits in the waste-gate but it took 2 full days to get the thing moving freely. Welded a nice pipe to the waste-gate and sealed the dump.


Ok, Soooo, so far my luck has been terrible. Thought since im doing things might aswel do them right. Got some nice 'ARP Head studs' and a monotorque multi layer head gasket!


ARP recommend 90 ft/lb on the nuts and man was that tight haha! I actually called them as i was scared i was going to break something tightening them that much. But they assured me that 90 is correct and all went well =)


Jetted up the carby...


And here is my "custom haha" intake pipe =)


Put the whole thing together in a ruff manner just to test how it drives and its awesome haha Now just have to tidy and braid all the wires pipes etc.. and ill put up the completed work =)

Here is what it looks like at the moment, please no laughing lol


I was told by MANY 'mechanics' and sigma pros lol that what i wanted to do would not work with this weber! Main issue they had is my intake pipe is pretty much vertical and that the fuel would not travel up and also had too long of a distance to travel. But, i still stick by my word, a turbo still sucks a fair bit of air even on idle and the path is not really that long...

Actually, i have a question. My waste-gate has a 9psi spring, what would be the limit of this engine (Astron 1 2.6) in terms of boost? Do you guys think i could go a little more or is 9 pushing it?

Anyways any input is welcome and ill be posting some more picks when everything is tidy =)

Cheers.

I ran my carby turbo at 15lb for a while. Makes a big difference but you have to get the timing and fuel mixture close to the mark.

What timing did you run? Also what was your AFR?

I would love to run 15psi but my auto box will die haha i will be getting a manual but until then.......

Cheers

Looking good. Almost went down this path but decided on 2.6 EFI turbo. As a result i have a narrow and a wideblock 5 speeds for sale as well as a complete 4g52 from a GH sigma for sale too if you need anything.

Haha i need that 5 speed box but shipping is a bitch! Still cant fine a cheap company to transport =(

DejanLazarov wrote:What timing did you run? Also what was your AFR?

I would love to run 15psi but my auto box will die haha i will be getting a manual but until then.......

Cheers

All trial and error (guesswork ) With timing I went full retard , advancing a little bit at a time until I heard detonation, they went back a notch.
Same with mixture, I am using the stock CD175 so it was just a matter of sanding the bottom half of the needle to add a bit more fuel.
Nothing scientific, and fortunately it all hung together. Good luck more than good management

Would locking the distributor here be a good idea? Otherwise wouldn't it advance under boost which is exactly not what you want it to do? Or, I may just have no idea.

U Me both with turbo tech Birchman.....no experience with it what soever (not my cup-o-tea)

Yous are BOTH correct! You pull apart the distributor and tie the weights and set a static timing =)

or better still, get a boost retard canister fitted to your stock dizzy at Scorcher Ignitions. http://performanceignition.com.au/

How much to get it fitted? Because 600 for a new distributor is a joke lol thats 30% the cost of the car!!!