BTW I went in to have my seals looked at and my Bakersfield mechanic said no problem with warrantying my work even with the full Manthey exhaust 410 kit.

 

Let's see. My car stock dynoed 348 at the wheels before EP. 372 at the wheels after EP (1 year later, same dyno). If you change out the headers, you can probably expect a loss in low end torque compared to stock. I attribute the greater hp than claimed by ep to be due to the motor loosening up...EP rocks, the contruction is second to none, imo...

 

By installing the headers, you will lose low end tq if you don't re-map the ecu. In doing the that, low end tq will not be lost hence having a complete power kit essentially. Of course the HP will vary slightly from the different kits and dyno's that are used.


Theo

 

THe Manthey kit comes with the ECU flash.
My previous owner was so **** worrying about warratny work he bought a
spare ECU stock GT3. As it turns out I didnt need it!!

 

We are in the middle of testing several options on the GT3.

We have 2.

One is a 1999 GT3 Cup car (comes with 100 Cell Cats and open exhaust standard) and we run it at Laguna Seca with the European GT3 street mufflers with no problems at all. Stock it actually puts out 410HP (supposed to be 370HP) which is one reason the new Cup cars have hydraulic lifters so they will be more consistent.

We then installed a set of beautifully done equal length headers. The peak power output was the same with a slighht drop (1/2 to 1 HP) in the mid-range. This was expected as the engine now needs more fuel and more timing advance in the mid range. Alas the older Bosch ECUs (ME 5.2) have a one time flash part, so we set it aside while we rounded up some refalshable parts from europe. These are located and will have some news before too long.

The other is a 2004 GT3 road car we first tuned with Revo's ECU software and after some work got an extremely smooth running car with 427 HP (100 octane race fuel) with no other changes. This car won the British Tuner GP previously (with some Revo tuning we did in the Bay Area on a GT3 with 100 octane race fuel). Shaun (Big Boyz ToyZ) was driving at the UK track he was very familar with.

Next we will put the headers on the road going GT3 and see how it does with the Revo Stage 2 software (for cars with instake and exhaust mods).

Just as a point of reference our little 2002 Boxster CS project car gained 13 RWHP with headers, 100 cell cats and sport mufflers. With just the Revo software (stock otherwise) it made 17 RWHP. With both it made 30.5 RWHP increase or about 50 FWHP. We duplicated this on a second car for assurance we had good solid measurements (DynaPak - direct drive to hubs).

Software in general will make a bigger difference (especially for the money), while both together make great HP. Finely tuned engines (GT3 Cup) need ECU software too because they are already running leaner mixtures to get more power with existing exhaust system.

On road cars the 400 cell stock CATS can rob power, but will last the 7 years/70K miles required in CA. 100 cell won't likely last that long.