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single,twin,compound for drag car ?

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im going to build awd drag car i use mercedes m117 4.5 liter v8 iron block ,soch 2 valve per cylinder fully build engine . which turbo setup best for me (twin,single or compound)?

It only depends on your power goal...

I would say packaging constraints and class rules are some other considerations worth noting.

"Fully built" means very different things to different people. As such, first things to consider are the estimated boost/torque and rpm limits of the engine.

From those you can assess the required mass airflow. Then you can assess the pressure ratio required. Then you can see if you can find a turbo-charger map that suits those requirements.

As I understand it, the two main reasons for using compound turbo' setups is for improved respond and/or an easy way to get high pressure ratios - that's why they're more commonly found in very high output IC and diesel engines running very high manifold pressures. With the latter, there are even 3 stage setups running over 150 PSI for drag and tractor pulling.

If you don't need it, I'd avoid the additional complexity of compound and run a single or parallel setup.

The target is 2000 hp. stock engine max rev is 6000 and creats 225 hp . now engine can rev 9000 rpm ,Aproximetly im going to need around 80 to 120 psi boost. which setup is better?

All projects I have seen with such a high boost level used compound type of turbocharging...

I concure, off hand, don't recall any turbo's with much over 4:1 ratio, and that's a lot higher than that.

That's a damn serious engine build, do you have a web site, or FB, it can be checked out on?

im not use any social media .i agree compound turbo setup better for my application, for compund turbo setup i can stay in max 6500-7000 rpm range also which turbo and a/r combination will be best for me? im going to use garret g series turbos


4.5 Liter blue print engine

2 valve per cylinder

max rev 7000 rpm

target 2000 hp on crank

what is the correct turbo size for my compound setup

Size the larger turbo to flow total power (something in the order of 200lbs per min) with a bit of flow margin (inside the flow map) at a pressure ratio of around 2.5, that will give a similar pressure ratio for the smaller turbo as well. This should give a reasonably wide and progressive power band for the circumstances. The smaller turbo should be around that fractional size of the larger, bias to a frame size/compressor up to account for the above ambient inlet temp.

Assuming porting/cam to make peak power circa 6800rpm.

You probably want something like a G55 2900 (106mm compressor) or a G57-3000 as the larger and a G40-1150 as the smaller. You aren't asking either for a massive workload so you can probably pick middle to top of the A/R range turbine housing sizes without hurting power too much. I'm guessing a couple of 50 or 60mm wastegates for the primary and maybe similar again for secondary to be safe.

Ideally software control strategy and pressure sensors to target PR for each stage, but depending on if you are trying to run a wide range of fuels or just the race full power capable you could get very close with appropriate purely pneumatic arrangement.

If you separated banks you could probably save money even buying 4 smaller turbos if you went to Pulsar G series clones. Could probably use G40-1150 or G42 as the larger and G28 or G30 as smaller.

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