Turbo Q and A

[PowermanX4]

Hi, I have been doing a lot of research about turbo's. I want to share my current understanding of turbo's, theory of operation and pros and cons, to see if I'm on the money with this topic.

Naturally aspirated engines usually build more power by adding more displacement via boring out cylinders wider and increasing the stroke. It's also a very good idea to get good breathing heads, nice carbs, and a better valve train, like a bigger cam, so you can force more air/fuel into the cylinder to go boom. This works very well, but the draw back is by doing this you increase heat, stress, and wear on the engine, thus decreasing it's life expectancy.

Now when it comes to Turbos, the engine no longer relays on natural aspiration. Instead of the higher air pressure outside evening itself out into the engine, the air is forced in by taking advantage of the exhaust energy. With a turbo, you don't need to have high compression ratio because the turbo forces in air at high speed, not volume, thus it increases life and improves efficiency. Now when it comes to boost, yes the engine is being greatly stressed, but if you have a good wastegate and a boost sensitive carb (I'm referring to the 1600t kit from www.vwturbokits.com) you only create more power when you want to. You will still need to build a beefy engine to handle all the extra stress, but if you're building any kind of high power performance engine, why wouldn't you?

If turbo's really do make your engine more efficient, yet only give you more power when you need, then would any car benefit from having a turbo? And if thats the case, why don't more VW drivers use turbos?   

[fatalifeaten]

Well, yes, pretty much any car could benefit from turbocharging. That's a generalized statement and broadly open to interpretation but fundamentally it's accurate. The caveat here is that the engine has to be correctly set up to take advantage of the turbo. Just slapping a snail onto an engine isn't going to make it perform any better or more efficiently. In fact, if you don't take the time to plan it out, it'll run like crap.

As to why more VW owners don't run hairdryers, they're actually becoming increasingly popular because the ACVW engine is very receptive to boost and there are many options to getting it done. Probably cost and skill are the 2 factors that keep most people away from turbocharging, but turbos are getting less expensive every day and more and more "plug and play" turbo systems make it to market all the time. Because of these things, it's pretty much a give that more folks are going to choose to boost. Someone told me that once you go turbo, you never go back ,and I think that's 100% accurate.

VW has been turbocharging factory cars for a while too. Granted, apples to oranges comparison there since it's air vs water cooled and computer controlled efi vs carbs, but there are TONS of fuel sipping turbo cars rolling off of many maker's assembly lines today.

If you have the budget and the time, There's no question in my mind. Boost it and drive it like you rented it with the insurance.

[PowermanX4]

When it comes to the turbo kits from vwturbokits.com, they use a lot of parts that can be used on not only type 1 vw's, but a lot of cars. What makes those specific parts ideal for type 1's? (Holley 350/500 carbs and turbonetics turbos) Also are there other choices of turbo kits available?

[fatalifeaten]

AJ simms (lowbugget.com/turbokits.com/et al) has been doing a lot of work with forced induction on VW's for a long time. The stuff he sells is based on lots of experience over the years testing and tuning, and dynoing. He also runs at least one drag car team.

As to what makes them ideal, it's a numbers game really. It'd be pointless to slap the turbo off a cummins diesel on a vw engine for example. just way too huge. You need to know what your heads can flow and then match your turbocharger to that. Different engines will want different turbos depending on use and equipment. CB performance has an EFI turbo kit, I think they're using garrett turbochargers in theirs. AJ's kits are probably about half of CB's though cost-wise. There are several other small shops doing turbos. You can find tons more info on the samba about turbocharging in the performance/engines section of the forums.