Upgrading tubro

Ok I'm new to the turbo world. I what to up-grade stock turbos to the 15G. If I have my boost at 14 psi is there a real need to upgrade and what would be the different in the up-grade if they are both set at 14 psi??

Ok I'm new to the turbo world. I what to up-grade stock turbos to the 15G. If I have my boost at 14 psi is there a real need to upgrade and what would be the different in the up-grade if they are both set at 14 psi??


you will need to upgrade fuel injectors and fuel pump, even if your still at the same boost levels, the 15Gs will will flow more air into the engine at 14 psi then the stock turbos, and therefore will need more fuel to compensate. I'd probably go with 550cc injectors and either a walboro fuel pump or a supra fuel pump. You could try hotwiring your stock fuel pump first and see how much more you can get out of it, but odds are you will still need to upgrade.

I am going to upgrade to 550 fuel injectors, Supra fuel pump, the air-fuel adjustor and gauge. I just wanted to know if it is worth upgrading the tubros before getting my engine redone, ie the rods and pistons and all the other good stuff.

many people have gone upgraded turbos on stock internals. The stock internals have been proven to hold up tons of power. Look at Matt Monet, he ran an 11.1 @ 129 mph at 5,000 feet above sea level (the correction factor is .8, so he would have ran a 10.3 at sea level) using twin t3/t4 turbos @ 21 psi on the stock engine internals with no problems, of course he's using stage 3 heads so that would be equivalent to a car with stock heads running 24 psi. Last time i heard, he was planning on running 30 psi on the stock block, so we know that the stock motor will handle the turbo upgrades. Matt was also the one who took 15Gs with a 70 shot into a 10.8 @ 128 mph on a stock motor as well.

Yep, I'd upgrade the turbos and supporting mods before working on the internals...

theres not much to worry about internally since the rods are already forged, and as long as you keep your air/fuel right then the pistons shouldnt melt until you get crazy with mods

Does the base and SL have the same interanals as the VR-4? I know they have different compression pistons. Can a base/SL handle high horsepower numbers as well?

yes for the most part, a few differences but still capable

Does the base and SL have the same interanals as the VR-4? I know they have different compression pistons. Can a base/SL handle high horsepower numbers as well?


they can handle a good amount of horsepower, but the first thing to go would be the pistons because of excessive knock due to the high compression