1rst Gear

If The hot housing is properly sized a T70 will spool at around 3.5-4k depending on static compression ratio and engine displacement, the 4k representing a 2.0liter engine with around 8.0 compression. A larger displacement engine with 9.0:1 C/R and (2.2,2.3,2.4,2.5,2.6,3.0liters -porsche 968) will come up much much sooner. A good housing size for the hot side on most four cylinder engines is between .63 or .68 any larger than that tends to shift everything towards a turbo set up that would benefit more from highway runs! The E-Bay T70's have a very large hot housing (.84 a/r) which is actually suited for a six cylinder engine with at least 3.0 liters displacement. Ball bearing turbos are definately worth the bread if you want a flexable set up with responce good enough for drifting and large enough for mind blowing top end power.......GT3076-R comes to mind and can be had for around $1200.....They're getting cheap!

You'd be surprised with what the single cam guys are capable of on boost...if it's built right they can lay down some pretty impressive numbers. Our shop right now has a single cam customer making 605 to the ground on a 3076-R. Pretty sick. That said we also have a customer with two star/quest one mpi and the other tbi which with minor mods and around 18psi boost on a evo 16g made over 300 rear wheel hp and and nearly 400 ft-lbs of torque! when he brings the mpi car back he's shooting for 400 with haltech management and with a little time and money there is no reason you couldnt do the same. G54B-T makes great power if your patient enough to deal with it's quirks, so I give you this advice. Do your basic maitenance first, and double check your ignition timing. Take baby steps when you start uping the boost pressure and monitor your a/f ratio closely. If you can afford to pop your engine and you just don't care thats one thing, but alot of people don't want to take that chance. Read your plug every so often to keep track of how accurate your fueling is and keep a close ear out for any pinging that can occur under high boost high load conditions. If you hear anything back the boost down or lop off some timing and you should be just fine.... Good Luck bro.. William 88' Starion ESI-R

I know it's been a while since I've posted so forgive me but what other mods do you have on your car? If you went to a walbro 255 and you don't have a fuel controller (Apexi Super AFC or another comperable controller) you over rich running condition may be caused by the additional volume and pressure the pump is allowing through the fuel system. If you swapped out the pump and now you have a problem then either try a fuel pressure regulator that can better control the pressure of the system (after the actual fuel pressure has been determined to be incorrect) or install an electronic fuel control device such as an AFC to dial back the fuel injector pulse width to provide the proper air/fuel ratio at a given rpm. Just be careful Most electronic devices change the airflow meter signal that the ecu see's and this can cause a spike in the ignition advance as the computer will give more advance when it is told the grams/sec air flow is low and initial throttle demand is high, in short pull back on the static timing of the distributor or back off 1 or 2 psi boost if you hear any ping after you install any such device that electronicly fools the computer into thinking it has less airflow going through it at any given rpm. Hope this helps William 88' Starion ESI-R

I agree mostly with what FlattopMike said until he arrived at the fuel grades end of the discussion.......That totally depends on what part of the country you live in. I realize that some places can't get better grades than 91 octane so that henders horsepower production because it forces tuners to use lower ignition timing and more fuel to ensure no detonation occurs. In most places however you can find 93 octane at the pump no problem,which is way better than the 91 octane that was available as premium fuel over a decade ago when these cars were still being produced. Also compression ratio,fuel injector pulse width and displacement,elevation and temperature as well as boost like what was already suggested earlier will greatly effect weather you can bump the timing on your car as well. In short this is a very tedious balancing act which would best be left to a tuner with a good stand alone or piggy back wired in to support ignition timing adjustment electronically, leaving the mechanical setting of your distributor locked in at 10 degrees BTDC like it should be stock. You can benefit greatly from increased timing under boost as well as before it, but it leaves you with little to no margin of error for tuning and fuel choices. You get much more torque off idle up to the point of gear change (provided you can remove the proper amount of timing under boost) and your driveability is better to the point of boost threshold (before boost kicks in) but this limits the overall amount of boost you can run (Think 14-15psi instead of 16-17psi) Also raising your boost pressure will only help you to an extent until you start reheating the charge-air after the intercooler due to the lack of compressor efficiency. This requires.....you guessed it more fuel, and less timing which ultimately yields less horsepower and torque. If you decide to bump your timing via the distributor, my recommendation is to not exceed 12dgrees BTDC and only run 93 octane fuel if you have it available to you. And don't run beyond 15.5psi boost. I ran my Starion with this same set up here in Austin in 100+ degree weather and didn't experiance any ill effects. Good luck with it bro William 89' Merkur XR4TI 88' Mitsubishi Starion ESI-R 90' Volkswagen Corrado G-60 97' Mitsubishi Eclipse GS (Daily)