Hi Guys, About a month ago I posted a wanted thread looking for a 348 for some new product development. We are developing headers for this car as well as a few other things so I figured I'd post some results as we go along. First we put the car back to stock (Came in with a Capristo race rear muffler) for baseline dyno results. The car put down a respectable 260hp to the rear wheels on our Dynojet and really good low & midrange torque. Next we bolted on our 200 Cell sport cats and picked up a solid 8-12 ft. lbs of torque across the entire powerband. The sport cats also picked up 11 peak HP to the wheels. The stock ECU calibration had a nice A/F ratio with the sport cats installed (low 13's). After the sport cats, we dyno tested our catbypass pipes, and the car REALLY woke up. Power shot up to 286 to the rear wheels, with gains of 20+ ft. lbs of torque across the entire powerband. I overlayed these graphs with 355 graphs we have, and I am VERY impressed with the power the 348 engine puts out, especially with catbypass pipes. It sounds great too, with catbypass pipes & sport cats, even with the stock rear muffler. With catbypass pipes, the car starts to run out of fuel (high 13's on the A/F). This is a good thing (meaning the car likes the free flow of the catbypass pipes) but must be addressed if the car was to see regular high rpm driving, or track days. Image Unavailable, Please Login
Wow, that sounds great. And the catbypass pipes use the stock ECU calibration as well? Speaking of sound; did you happen to measure the decibels (baseline and others)?
Thanks for posting the graph. With those types of increases I am going to have to do some serious thinking about going the bypass route.
Great start. Now bore the throttle bodies, hog out the runners and smooth bore the intake plenum and you are a Stooge. Then don your tin foil hat and remove your MAF screens, adjust the resistance and think about how you can ram more air down those tubes. Oh, and for good measure, change the fuel lines by the filters to larger diameter - there's a restriction there. You can also boost your fuel pressure slightly with an adjustable regulator.
It would have been especialy informative if you had also tried the next larger size CAT (also with 200 cell) to see if it was the fact that a cat was present or the fact that the CAT had insufficient flow.
Hi Mitch, 200 cell cats in general are very unrestrictive - especially if you have 1 for each bank of 4 cylinders. I believe the difference comes from the velocity differences in gas speed and how this helps/effects cylinder scavenging. Each car, with their unique geometries and valve timing, will respond differently. At the moment we can only measure pressure, and there is only a very small difference (.5psi) between the two.
Hey guys, These sport cats and catbypass pipes are ready to go!! I am getting 2-3 sets through fabrication within the next week or so and I am also taking orders currently! If we can get 3+ confirmed buyers off of Fchat then I can start to think about giving you guys a discounted price, kind of like a mini group buy! Let me know what you think Shoot me a PM on here or email me at Evan@fabspeed for exclusive Ferrarichat pricing!
Any idea when the headers will be available and what the expected performance benefit will be? I have an engine out service early next year so I may be tempted in getting a set.
Here are some of the preliminary results on the 4-into-1 Fabspeed 348 Headers: We dyno tested the 4-1 headers with the Sport Cats installed as this is the setup we feel most will go with. Mid range power was improved significantly. +20 ft. lbs torque to the wheels with the gains starting at 4,000. The improved torque maintained all the way to redline, with peak HP gains of 10 to the wheels. There was a slight loss in power below 3700, which is to be expected with this header design. Nothing to fuss about as the gains strongly outweigh the loss. Below on the dyno graph, the bottom green line is the stock baseline. The middle line is Sport Cats only, and the top line is 4-1 headers & sport cats. Image Unavailable, Please Login
Also we had a Capristo Race rear muffler as well as the stock muffler - I wanted to see if the Capristo produced any power as claimed, and I was disappointed to find that it produced no horsepower over the stock muffler. Great sound though (too much drone for a weekend cruiser, but great for an aggressive driver). Image Unavailable, Please Login
The basic (non race) version of the cappy for the 355 only added 7 RWHP when I tested it a while back. What type of RPM monitor are you guys using on these dyno charts?
Nice numbers Chris, especially the midrange gains. You can defiantly feel those ponies via the butt "dyno". The cars accelerate much better. Out of curiosity, what was the a/f ratio on those pulls? I'm guess an x-pipe exhaust is next?
Fabulous power pick up with those headers. What's the tubing size difference from stock headers to yours? The stock bends must really suck! 270+ at the wheels is an achievement for an otherwise stock internal motor.
