This has probably been beaten to death but could not find by searching past threads. Will 360 headers...intake plenum....and throttle body bolt-up to the 355?? I did find one post that refered to a redesign of the 360 heads but did not go any further. Thanks for any help Bruce
My gues is they changed the bolt pattern. They did from the 348 to the 355. So it would make sense they changed them for the 360. Though plugzit made adapters for his 355 throttle bodies on his 348. One could possibly do the same for the 360 TB's on the 355. I would not mind going to dual TB's as in the 360 on my 355. I think it would be more likely to have 'equal' air to all the cylinders.
Anything will "fit" with a mill and a welder. Instead of stacking parts with adapters I would cut off the flanges and weld on specific ones for your project, thus keeping the overall height the same and eliminating extra gaskets, nuts and bolts. I was going to do the 355 tb's but Plugzit won them so I chose the dual tb route like the new f-cars and basic hotrod 4cyl dohc tech. However, when he gets the stacks set-up on it, it will be awesome!
Group77......that sounds familiar.....I remember when I was racing Grp5 in IMSA there was a race team with this name running a Jaguar....did you have any affilition with them? I'm impressed with your 348 mods.....awesome design work and believe that all 348 and 355's should of had this setup...they f#@ked up the 355 intake when they changed the 2.7 to 5.2....challenge cars always stayed the same and the only mod I would have made to them was to have a crossflow between the 2 plenums like the 360. And another mess was the by-pass exhaust which possibly causes MAJOR problems with the headers(?), valve guides(?), clutch(so that is why Challenge cars had the drilled housing?)), and engine bay temperatures......albeit the sound factor was unique for cars(note:355 ONLY ONLY ONLY..F40/50 and 360/430 is a completely different system) running this set-up, but there is a better way to achieve this without the associated problems....IMO getting rid of just the bypass valve(ala Challenge cars) or changing the by-pass pipe(ala Kreis-sieg) is not the total cure...look at the post with GruppeM's exhaust...that is how it should be done(hmmmm..no by-pass,no air rails=less temp?,longer primary tubes, and a different collector), but I'm not up for 10g's...YET(lol). I wonder if someone has a 360 exhaust header and throttle body handy to compare with the 355??????? The factory designed headers are an amazing work of art and I could not replicate in house but want to use the bends and extend the header lenght before the collector and maybe increase the collector outlet. For the intake system the 360 is very impressive and believe that this design will pay off with significant gains with flowed heads and 1mm oversized valves. Help from anyone will be greatly appreciated.......this is just the design phase so throw in any suggestions. Bruce
The bolt pattern was changed because the heads themselves are different - the 355 went to a more compact head with 5 valves, the same as the 360. It's possible that the plenums might just be a straight swap, unless there are some additional mountings in the way. Likewise, the 360 heads may bolt onto the 355 lower end, possibly gaining some development of the 360's flow. Another hardware/software issue in itself..... Might be time to go Motec at this point. Or just plug a whole 360 engine/ECU unit into the engine bay.
Two other things need to be addressed.....(1)fuel system on 348 and 355(see Group77's mod for restrictive fuel lines)...also pull those injectors and have them tested(RC Engineering....flow and spray pattern)...I have seen some real problems in this area......... (2)ignition system.....why not individual coil packs like 360/430....at 8,000+rpms the 348 and 355 oem may cause an almost imperceivable hickup....what does this do to performance and what does it do to the engine??.....I know in our Grp5 Porsche's(twin turbo 800hp+) it would crack the headers...until we went with inconel. Sorry for getting carried away with all this....I'll blame it on the coffee! Bruce
Headers seem to be the same basic unit between the 355 and 360 - same mounting flanges and shape. The 355 obviously splits at the exit. Image Unavailable, Please Login
Is that a 355 header that you can just barely see to the right? So do the flanges on the 360 match up to the 355? It is very interesting that one of the 360 headers seems to be longer than the other...WTF is up with that??? Am I just crazy or what....this goes against everything I know about header design. Oh well...that can be refabricated. I am going to order a case of Jack Daniels and a box of cheap cigars and do some more thinking!!!!!!!!
Excuse me for the last post.....I didn't take the time to look at your pics properly....so the header at the top is 360 and the bottom one is 355(without air rails)??
The one in the front (at the bottom of the picture) is a 360 header, the one in the back (at the top of the picture) is a 355 header. Here's another view: Image Unavailable, Please Login
Wow, one can see how even the cylinders are running on the 360 vs the 355. That 355 seems to be running a little on the rich side. Hmmmm 360 headers on the 355?? I wonder if not running the "bypass" would hurt the 355 (horsepower wise)??
Valence......about 7 years ago I bid on a climate control via eBay and someone contacted me after the bid wanting to buy it from me because they were going to make molds for a new cover to market.....was that you?? If so I apologize for not responding....... The rear part of the 360 exhaust will have to be refabricated because of the difference in the gearboxes....the 360 front clutch gives you more length before encountering the drive axles. Valance are the primary header pipe ID's the same?...what about the ID's where the cats attach?...your help is greatly appreciated! Here is a question for ALL......as far as I know the 360's did not have header failures.......was this because they were made from a thicker guage material?...if not(which IMO they weren't)...what would you guess made them more reliable?..
Goth...I sincerely believe this project will benefit ALL of us that have poured our heart,soul, and money into making these(355 primarly and 348) cars produce greater hp in a relaible and easily maintained(cost effective) way. IMO the bypass exhaust on the 355 is a design flaw(Ferrari will not admit) that only produced a sound unique to this series....at the expense of high cost repairs. Screw the back pressure theory.....everyone knows that the best exhaust is in fact no exhaust.....so to live in the real world where noise and pollution are concerns we try and build headers that try to overcome the back pressure created by cats and mufflers.
That's partially the camera angle, but you're right, and guess which header tube failed on that 355 manifold... Yes, my thoughts were also on putting 360 headers on a 355.
It was probably me - but I have long since become intimately acquainted with these climate control panels. Primary inlets are identical - the flange is clearly the same SS casting. ID of the 360 outlet is slightly bigger. Header on the right is 360, left is 355. Image Unavailable, Please Login
When you are running rich like that(this is due to the bypass system...cats in the bypass pipe vs primary cats with O2 sensors..and the way header splits them)..and you blow oxygen rich air(via air rail) you get secondary combustion(maybe that these temps are higher than what is in the combustion chamber) that fatigues the header metal, destroys the primary cats, O2 sensors, and guess what????....elevated head temps which cause premature valve guide wear. Bottom line.....if temps are that elevated surely the hp must drop. Any opinions on what we have covered so far????
Valence....I really appreciate the help. I am wanting some carbon for my car...can you help??...PM me. I also have some ideas on interior we can explore...he he he
Cool, I will. That's what I need to be focusing on anyway, but you guys keep coming up with all these interesting discussion topics.
Hope everyone is enjoying this thread.....relax....get a drink of your choice and whatever you smoke and lets keep on this until we prove to Ferrari that our street cars are just as important to us as their F1's are to them
Could anyone please help out on the Throttle bodies? These are parts that few would have just laying around but any input would be of benefit.
Here is some interesting info : HOW HEADERS WORK Headers are much more than just suitably sized exhaust pipes attached to your engine. Headers are an integral part of your engine. The significant energy remaining in the exhaust gas in the cylinder after the power stroke can be used to increase engine power and efficiency by: Minimizing the contamination of the intake charge with exhaust gases. Starting the flow of induction during the valve overlap period. Minimizing pumping losses on the exhaust stroke. The header performs its function by: Utilizing the compression wave that is created when exhaust pressure in the cylinder is blown down after the exhaust valve opens. This compression wave travels through the exhaust gas remaining in the primary header pipe, and accelerates the exhaust gas toward the collector. Passing this strong compression wave through an expansion chamber (collector) located at the end of the primary header pipe. This produces a strong suction wave. This suction wave travels back up the header pipe toward the open exhaust valve, accelerating the fresh exhaust gas in the pipe toward the collector. Timing this reflected suction wave (scavenging wave) to arrive back at the exhaust valve during the valve overlap period, when both the exhaust and intake valves are off their seats. For the header to function properly it must have the following characteristics: Primary header pipes must be small enough to maintain the strength of the compression waves and suction waves in the pipes. Primary header pipes must be large enough to allow optimal flow of gases past the exhaust valve, and down the header pipes. Primary header pipes must be of proper length to ensure correct arrival time of the scavenging wave that will be reflected back to the exhaust valve. Collector must be of proper diameter and length to provide the correct duration and intensity of the scavenging wave. Primary header pipes and collectors must produce a scavenging wave that is present at the exhaust valve during the valve overlap period over an established operating RPM range for the engine.
Great thread here, interesting stuff. You guys probably know this, but the Ferrari explanation for the exhaust valve was that higher backpressure increases torque at lower rpm. So it makes sense to want this in a street car, but rather go for peak flow in a challenge car. And going to two throttle bodies seems tricky from an ECU / injector control standpoint. Maybe one of you would know - is there any way to monitor the various sensors using a laptop through the OBDII port?
Goth......let me clarify.....when I said " no exhaust system", I was refering to everything after the primary header pipes(ie top fuel dragster) or the collector(most track cars ie F1).....this includes bypass pipes, bypass valves, primary and secondary cats, and mufflers... Headers are an extremely important part of the tuning process.....the bypass system is definitely NOT(esp the 355).....and in my opinion a MAJOR problem area. If you desire more info and do not take my word for it, you can read more on this topic by doing a Google search......you can also go to overboost.com and look at an article titled "Exhaust Theory".
OK then we are on the same page !! You are right! After the collector it should be wide open !!! But since we can't do that on the street, we might as well go with an X-pipe too !!! I am seriously considering going to a 360/430 style intake manifold. The goal would be two (maybe even one) throttle body(ies). One throttle body would only be because I have only one MAF (1997 ) Had I known that there was such a thing as a dual MAF 355, that is what I would have bought. Needless to say my valve guides are upgraded and I bought what I bought . Back to the subject . As for the exhaust I would love to get rid of the secondary exhaust path and go with a 360 style exhaust. Now the logistics of making a dual throttle body manifold.... I have a pretty nice machine shop here, so the problem to me would be: How can I switch (if possible) to dual MAF's??
Hi Dave Ferraris' statement may not be exactly the truth nor the whole truth.....inherent in any emission and street legal(noise) exhaust system is sufficient(often excessively restrictive) back pressure for low end torque(would love to see dyno torques in relation to bypass valve flow)....the bypass system was too eliminate some of the back pressure at mid to wot by giving the exhaust gas a less restrictive path....and with any fluid or gas it will tend to take the path of least resistance....but it does not mean that some of the gas is still not being forced into the primary(most restrictive) system where the O2/lamba sensors are at.......now I have two systems(primary and bypass)...one monitered and one not.....my question at this point is......What part do the 02/lamba sensors play in the ECU at mid to WOT???? Can someone please elaborate on this??? As far as torque difference between street w/bypass valve and Challenge w/o bypass valve.....is probably very little. Just remember that I am saying that the whole bypass system is a problem and not just the removal of the valve. Concerning the ECU/injectors....there are guys like Group77, plugzit, etc.......that have already done amazing projects and am sure I their expertise will benefit us all.
