Hi all, Just thought I'll post my experience with Fabspeed having first dealt with them. I ordered my headers via email and it was supposed to be sent to LA where a friend would collect it and bring it along with him to Singapore where me and my beloved Spider (1 of the only 2 left in the country) live. After payment was made and while the headers were being made, the sales person who handled the order left Fabspeed. Hence my delivery dates were all screwed up and the headers never made it in time. Here come Alex and Jeff to the rescue. After explaining the situation with them via email, the headers were freighted to Singapore at Fabspeed's cost (very nice of them to do that). And now that the headers are fitted, all I can say is that the feel of the car is transformed! From 3k rpm onwards, the car is so much livelier. Did not dyno the car but the seat of the pants feel is fantastic and there is so much more torque from mid range onwards. And it isn't the placebo effect as I had this car for quite sometime. Only thing I miss is the higher pitch shriek of the OEM headers. The car now has a deeper tone from idle all the way up the rev range. Car was originally set up with OEM headers,straight pipes and Tubi box. So all I can say is THANKS Fabspeed! You have one very pleased customer. Now for your opinion guys: I live in the tropics where temps are usually 92 in the afternoons most times of the year. Headers are ceramic coated and since I do not have cats, is that enough to ensure that my components near the headers do not get cooked? Last thing I want is to increase the unreliabilty of the car which has been great for the past 2.5 years and 10,000 miles that I had her. Thanks in advance.
You can drive mine and see how it feels vs your all tubi exhaust. Maybe this Sunday? Will ask the other 355 guys if they want to meet up again, Ian has installed the challege steering rack so I'll like to see how that feels. Let me know if you are keen and I'll email the gang.
Thank you for the kind words! We try to keep everyone happy! With the heat shields in place, you will be fine with the heat in your engine bay. Enjoy! Jeff [email protected]
Thanks, this confirms that the shriek comes from the small header tubes. My CFD analysis indicates taht when the exhaust gasses are still raveling above Mach when they reach the expansion chamber. The shriek IS the sound of a supersonic gas flowing into a non-supersonic gas.
Interesting theory. It has also been speculated that the 4-1 vs. 4-2-1 collector configuration is responsible for the sound difference.
Thanks guys, I have been interested in the Fabspeed headers but was concerned that the 4 into 1 design would trade off mid-range for top-end. Question for Jeff at Fabspeed, has he seen and what is opinion on the Capristo heat shield bags that go over the headers?
Given 2 different header architectures (4-1 and 4-2-1) that are both well optimized for "best" power at the "top end", the 4-2-1 system "can" have a slightly longer mid-range. Where "best" means as much as possible given the RPM limitations of the ECU (8500 RedLine, 8700 = fuel cut-off) and simultaneoulsy as much low end as possible given the header architecture and tube sizes can muster. Where "can" is about 250-300 more RPMs lower in the Rev range where the header comes on-song. That is, a 4-2-1 designed for top-end does not give up anything (excepting weight and cost) to another properly designed 4-1 header. However, the non-factory-copy headers, that I have observed, have header tubes that are not long enough for the tube diameter and the RPM range of the F355 engine. As header tube diameter increases the length of the tube necessary for proper header tune also increases. So for every 2mm of tube diameter increase you should be looking at 30mm of additional tube length. The non-factory-copy headers I have observed, have increased tube diameter (which enhances power) but have not increased tube length (which moves the power band higher in the rev range and saps power down below.)
Wow, sorry for the super slow response! We have never fitted the capristo bags on Fabspeed headers. My guess is that they would fit since I believe that they use one size for 355, 360, and 430, but I haven't confirmed this. We supply two heat shields that protect vulnerable components in the engine bay, so the caprristo bags are not necessary. Jeff
