Does anyone know of any twin turbo cossie engines, was looking at some dinky journal bearing turbos at work today and wondered if one could be made to wake up a T4 a bit earlier in teh revs..

Any info or ideas on how to make it work? would a little turbo be able to hold back the boost of a t4 at say 28psi through its compressor housing?#

I'm sure I've seen a twin turbo'd cossie engine in one of the mags before somewhere.

Cheers
Dan

 

Im sure turbosystems tried out a twin turbo set up years ago, and AVA compund charged Dumped's car.

 

dumped on here had a twin charge setup didint he ?


beef

 

AVA built a compund charged Cossie for Dumped off here. PM him and ask about it

 

 

iv seen a vid of that on the road and it was a bit mental but i have seen a rallyx focus with a twin turbo set up on a yb

 

wow thats impressive! How much power was it? and was it succesful?

 

on the 1st turbo does the outlet go to the intercooler? (not the exhaust outlet)

 

I'm confused by the last pic...

Can't make out what goes where. I reckon I've got this totally wrong but do I see the small turbo inlet going into the big turbo outlet?!?!

 

can't see myself ever wanting past 500-550 from a YB and that comes so easily on a 3076 with very minimal lag anyway.

be interesting just for the sake of doing it though even if end result was nothing better than a good single turbo.

 

Mark Shead told me on a thread, there wasn't much space and I think he also said he had a good enough rev range from one big single turbo.

 

wowwowweeeeeewowwwwwww

 

Another one of ava's great mysterys

 

Thats pretty much the standard issue way of doing it, you blow the big turbo through the smaller one.

Happens shit loads in tractor pulling.

 

I was chatting to a guy at pod with a compound charged drag bike (hope to see them again this year, nice blokes) and he was explaining all the details of how he did his. I forget all the details now but he was saying how blowing one into another created a ratio of 3:1 for boost ie 1 bar +ve into the other turbo created 3bar +ve in the larger turbo. I seem to remember the reason being a small turbo will reach 1 bar (and thus create 3 bar total) faster than one big single turbo?

Thats all from memory though and I could have got my wires crossed

 

I LOVE looking at the pics... and it is cool as hell in a way!

but lets face it... pretty pointless and the car never did anything did it?

Shame I do love different stuff like this.

Cant help thinking... easier to just start with a bloody great 6 litre V8 in the first place though!

 

Im sure the car spent most its life on the rollers then got broken

 

I have no personal experience of compound charging, only information gained from others who have done it.



Fundamentally though the basics seem to be:

- The large turbo wont make as much power as it would without the smaller one also present

- The small turbo wont spool as quickly as it would without the larger one present

- You'll make more power than the small one could, and will spool quicker than the large one can


- unless you are wanting to run huge boost pressure (the 3 bar you mentioned wouldnt even be the low boost setting on some compound charged competition diesel motors!) its very unlikely you will be able to better the spool and power of a well matched single turbo.

 

LS2 all the way baby!

Get one into your westy ASAP

 

Do you know why though?!

One snapped crank. Then the inability of anyone to guarantee a crank would take the power. Would've been amazing had it been finished.

 

So did it have more power than rod tarry's , andy g's , martins escort , & such likes ? what power did this end up making before the crank snapped?

 

Rod's crank has been rated to 1000bhp I believe.

 

I cant be certain on wheel power but it was pretty high and on minimal revs and mapping. It certainly had the potential to be right up there. It's not my car so i dont want to say too much about it.

 

The crank story i would take with a pinch of salt , in the real world could you ever see that car being practical & working ? again ava trying to make something different.when you get mark shead staying with one turbo & getting results without making things alot harder like above.Seems to me like they make things harder for themselfs.

 

so how is the big turbo mounted and what drives it? cant make it out

 

The smaller Turbo drives it. Thats how I understand compound charging

 

think its all trial and error..some tuners dont like to stay with the norm and head for the next level like ava tried to do.

 

The big turbo is driven by exhaust gas, as is any turbo.

 

Not really true from what I have seen, the smaller turbo will flow some exhaust gas which will then go onto the bigger turbo, but typically the smaller turbo will also have a wastegate (either internal or external) to allow much of the exhaust gas to bypass it completely to prevent over spooling it, and both the gas that has gone through the turbo and the gas that has gone down the wastegate is then directed back into the exhaust inlet of the bigger turbo.

 

Maybe they should learn to walk before they try and run, its no good going to the next level of having two turbos, if you still cant match the power that people like Sheady get with one surely?

 

I know Martin very well and thats the truth. There was development on the engine exactly like the other have gone through when pushing the power. Unfortunately this wasn't an open cheque book job! Also this wasnt alans first TT cossie!

 

Cranks break for many reasons, what makes them so sure it was "power" that broke this one?

And what power did it make before it broke the crank anyway?

 

point taken Chip

 

gotcha. thanks

 

I know it damaged the crank and one of the arrow rods , was making similar power to Euans car but over 3000 rpm earlyer from what i have been told.

 

Sounds like a build error to me then, those arrow rods should be good for 1000bhp and similar torque!

What rpm is 3000 earlier than euans, I dont know what rpm his made peak bhp or torque at in the first place?


what was the bhp and what was the torque on this TT thing?

 

My crank is rated at 1000bhp so if you pays your money such cranks are out there.

 

Wether or not this car/turbo setup did/would've delivered the goods i love it for trying to be different, always nice to see unusual things being done.

Cheers for the info chip, ive learned something new today

 

would a YB flow enough exhaust to spool 2 T25's, ie 1 turbo per 2 cylinders and would there be any point?

 

Turbo Technics built a 4x4 twin turbo cossie in about 91/92 it was featured in performance ford mag around that time..

steve