TTP Tuned BBK Lite + QTP Cutout= Big Gains!

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Jun 9, 2009 | 01:21 PM

TTP Engineering

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From: Central FL

TTP Tuned BBK Lite + QTP Cutout= Big Gains!

Tim has had a rough few months with his car. We started out working with his car a few years back and always had good results with his 2003 Evo VIII. Somewhere along the way in an effort to cut a few corners and save a few bucks, he got off-path with TTP and found himself in a less than professional experience with some "drop in pistons" elsewhere. As we have been advising against lately his results elsewhere were less than great.

Long story short, his piston to wall clearances were not right, his honing angles were wrong, there may have been grit left in the engine, his car burned oil and to the point where it ceased the motor. We spoke about building the motor for him, buying the car outright in its current state from him, but then he settled on keeping the car with our advice to just buy a used replacement engine.

Tim found a local 2003-2005 Evo engine and had it shipped to us here at the shop. In a day and a half we had the replacement motor up and running and strapped down to the dyno rollers. To offset the cost of his catastrophic engine failure from the "drop ins", he sold a number of performance parts off the car such as the methanol injection, cams, springs and retainers and so on. The replacement engine had stock springs and retainers, stock cams etc.

Tim opted to keep the BBK lite, Injen intake and QTP downpipe and TTP O2 housing, with walbro fuel pump, injectors and Forge RS BOV.

Tim decided he was tired of "paying to play"and wanted a reliable pumpgas 93 octane car for the forseeable future. So we went to work tuning the Lite BBK to 333whp with the stock catback and catalytic converter and with the cutout open and NO tuning changes, the power jumped to 370whp as the restrictive exhaust was bypassed so the engine could breathe better.

Here are the numbers with the cutout open:

Here is the graph of the cutout open compared to the cutout closed:

Jun 9, 2009 | 06:48 PM

EVO8LTW

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From: Northern Virginia

Just curious how much of the HP loss you think was the stock cat vs. the stock catback, and how much gain there might be with essentially an open DP vs. a regular 3" TBE?