Lots of people are torn as both methods offer a great power increase. It just comes down to what you really want vs. what you can afford. The twin turbo set ups are at the top of the food chain and of all the twin turbo kits out there the Granatelli/TTi system offers the most power with superior fit and finish. We are talking about “real” production style kits. You can always find companies that promise the world with no ability to deliver. I have exhausted my opinion as to why I feel the turbo is the best choice – But basically it makes the most power (or should I say, it has the ability to make mega power and always superior torque).
Our turbos are mounted directly off the exhaust manifolds – Here are a few pics:
The black plate you see is spaced down .75” This allows cools air to vent over the turbos – it is natural airflow and therefore has the same cooling effect as it would on a stock application.. (We do not offer the muffler turbo style kits – they have tremendous turbo lag. As an example we dyno’d an STS kit the other day and at 3800 it had only reached 3psi on its way to 7 at 6000 rpm – that is just not right)
Turbo Lag – As defined lag is the delay or time it takes for positive pressure to reach the intake after going WOT (wide open throttle). In the past, turbos would have a lag, meaning it would take more time for a turbocharger to get positive pressure than say a roots type blower. What they don’t tell you is it takes a ton of power to drive the blower so it is all a trade off – fast forward 20 year later and it still take a ton of power to drive the blower but turbos have come a long way and the way they work now, TWINS have virtually no lag. That means when you step on it – you see positive pressure in the manifold. Search any Granatelli and Hellion customer on this board – NO ONE complains about lack of boost right off idle. – Therefore LAG is a non issue with Twins – single turbos may have a small amount but nothing to worry about.
If you see power drop off in the graphs it is because we are all turning the dyno of at that point. I can tell you for sure our turbo kit will just keep making power until you blower the engine up – it does not give up at any RPM – the camshaft may drop off but ….. it will pull until you lift – I think the dyno graph are confusing you – if you are comparing our TT kit to say a Maggie – the Maggie may have more torque below 2000 rpm but after that – we win hands down all the way to 10,000 if you have the balls to go that high
You do not need to forge the internals if you plan to stay below 575 to the tires
Something just came up – I hope to complete this tonight – see ya