F355 - how to simplify the engine bay.

All is good except the valve, I would keep that unless your increasing engine displacement a bit and run different cams with an ECU change.

The cars powerband requires a bypass valve to make the most down low power with the Bosch ECU


CELS are simple and great indicators of problem areas, I find them extremely useful street car.

Air injection is an electric pump for 60 seconds so no big deal to keep

Y pipe or a crossover pipe really helps exhaust flow but yes the stock one can greatly be improved. A Goth duel Valve system is the setup.

We like to run cats here in SoCal just for the challenge and to keep the smell down in our spiders.

 

Best way to not throw cells is to keep the car stock and maintain it correctly.

 

Yes pretty much what J says, a really good running stock really screams. Unfortunately too many folks take shortcuts and just because they don't throw CELs they think it's perfect .

Hi Flo cats are great sure but honestly a good exhaust properly designed will cut down on weight and increase flo.
One thing to remember sound is not HP.

I have 3 challenge cars at 3 different performance levels and 1 street spider that I run 100% stock just in as perfect tune as I possible can

 

There's not much superfluous in there. You can get rid of the cats - I bought my car with cat deletes and honestly, don't like them. It smells at cold idle and is louder at idle and low revs, which I don't care too much but no need to make a lot of noise when you're just sitting there. I plan to add them back on but gut the secondary cat. The cat temp monitors are also probably worth keeping if they're working and you have cats on the car. If they're giving you trouble...Well they can save your cats and/or engine if something goes wonky, so might be worth maintaining. If you don't have cats, get rid of them and pull the bulbs, they won't be doing anything and if they malfunction you get half of your motor shut off.

If you look at the challenge cars, about the only thing they removed were the rain guards on the sides, and for a street car I'd keep them as they keep stuff from getting too wet.

I like the valved exhaust, if you want light and simple (and loud) go for the challenge straight through exhaust. I have one on mine and I really like it. It also knocks about 35-40lbs off of the back bumper, stock is about 45lbs, challenge about 8lbs. It might be too loud for you, I really have to take it easy in normal driving to not make a lot of noise, but then when you crack it open all hell breaks loose.

Good luck and enjoy!

 

What shortcuts?

 

Maybe shortcuts is not the correct word but I am a drama queen

Mostly during an engine out items not addressed

I really wonder how many 355's don't have an intake leak of some kind
Properly responding 02 sensors, appropriate fuel trim and related parts
"Correctly" working bypass valve
All the up and down stream related parts that effect this and verified working not just done.

These are the most important things for a street motor that's as finicky as ours.

Sure they run never throw CEL's but drive one that has been "blueprinted" if you will. Quite the difference.

 

Yesh, keeping a 355 with all it's odd OBD II pieces is drama.

 

Piece of pie, mmmm pie

 

Going back to the comment aboutd the Y pipe, I would say my 355 challenge has a bespoke manifold and does without Y pipe. This has a few benefits: the engine bay runs a lower temperature and I think the more streamlined architecture works better from an efficiency perspective, finally the overall set up is much lighter.
Now It's quite an investment as you essentially have to change the whole system.