Responsive Barra Power - what parts are required?

[Woznaldo]

The Barra is a monster on the drag strip but, what if you want to make an M5 chaser? I’m not talking straight line. I want a tractable and responsive motor.

 

My current thoughts are 400-450kW is probably more than enough but making that as responsive as possible would be the aim.

 

At this point I should state that I’ve never driven a Barra Turbo motor so this question may seem a little blind.

 

My start point is an NA FG motor so I’d pull it apart and throw in some pistons and rods but, I want to do this for reasonable money. Most will probably say that OEM Cams are good for 450kW, which they are but, could a decent set of cams make the engine better in the mid range for drive out of corners?

 

Compression ratio is also probably worth considering too.

 

Lets assume the chassis and brakes are sorted and the ZF has had the required 6R80 mods done. So let’s go from here:

 

Valve Springs:

Retainers:

Camshafts:

Head Studs:

Head Gasket;

Pistons:

Rods:

Girdle:

Oil Pump:

Timing Chain:

Chain Guides:

 

Intake Manifold:

Injectors:

Turbo Manifold:

Turbo:

 

I’ve some packages that cover off on a lot of the above but, happy to take any recommendations.

 

Thanks.

Edited 05/07/22 01:38 AM by Woznaldo

[Tom Tucker]

Hey mate, depends on how far you want to take it. If you want response and power you really need to address drivetrain, and rear end grip.

450kw is perfect for the street, and a cake walk for mostly standard parts.

It sounds like you want to do this for reasonable cost, so if you really only want that power level, go stock turbo manifold, GT3582 or GTX3582 and build it around that. 

If you want more, have a look at my build thread.

[hjtrbo]

The stock variable cams and off boost strategy are very good. They do help to spool up quicker.

 

Tom's advice is excellent. The 3582 and newer versions of it are a great turbo for mid 400's on the corn juice all day long for many 10's of thousands of kilometres. 

 

Whether to upgrade I think will depend on your level of tuning experience. If doing it yourself and you've had no variable cam experience I'd suggest leave the stock cams. If going to someone like jeturbo etc. just do whatever they say. 

[adams355]

The turbo barra in a BA BF FG falcon is not a drivers car. It can be made to perform decently but not well. It is a straight line car at the end of the day and at best a tourer. Its always laggy with a single, its never power on the foot like an NA etc. Its always a best guess throttle input scenario for the conditions. Its not like a race car which is extremely predictable and has no issues with input at the limit of grip (sideways etc). But saying that on the road, tuned etc it can easily be faster than a M5 but not as fun to drive would be my bet from a driving perspective not power and speed.

[Woznaldo]

I agree with your points. I’m really talking about the engine and drivetrain here. They will going into a ‘73 Jag XJ6 so the handling won’t match a modern sports sedan without an excessive amount of work, and even then there’s no guarantees. I just don’t want a lag monster. A modern turbo  could really change the driving dynamics. I do have the luxury of a Haltech Nexus, so lots of tuning strategies can be applied!

 

I’ll stick with the stock cams but as it’s an NA car and people now charging ridiculous money for std turbo manifolds, I may have no choice but to go aftermarket?

[adams355]

The cams are the same in all the barra's (ie turbo/na) and work well for lots of power. A lot of the issues with the falcon are weight orientated so you will likely get a nicer car to drive with a lighter chassis and most of those issues I brought up will not be as bad.

 

You just have to keep an eye out everywhere for some cheaper prices on parts they do come up. 

[Tom Tucker]

Cams are worth it for sound, and the fact that most standard cam lobes are worn or damaged after the kms these engines rack up. 

Recommend either Atomic, Kelford or Crow. Aim for 90-105lb valve springs - the easier on the valve train the better at your modest power goal.

[k31th]

I love how 400-450 is now "modest" from a power goal perspective hahaha

[Woznaldo]

Ha ha! Too true. I’ve been watching the Barra scene for a while and 400-450 is valve springs, remap, send it!

 

Thanks for all the replies. I’ve got something to work with now. I’ll get the car up and running in NA form first while I source parts. Getting the ZF in the Jag will require some tunnel work, so plenty to keep me occupied!