3 inch 575 exhaust and images

I posted some images last week in the technical Q&A in MAF vs MAP thread, here they are again. The Tubi tips shown are only stock diameter. They are being replaced with 3 inch in/out cans. Because they encourage bigger bangs and lose less exhaust energy going through, the big pipes need more silencing. The car is louder despite the 3inch x 36inch resonators compared to the same Tubi tips on the no muffler stock exhaust. The "classic V-12 sound" they make would please all of you and make the change worthwhile despite the big power increase you would have to live with. The cost was $6k for the pipe fabrication. A pair of high flow cats could easily be welded into the cat delete pipes if needed.

Stop watch testing in 3rd gear from 100kph to 160kph (4850 - 7500 rpm) has shown repeatable 3.8 sec. Realising we are not exactly comparing the same thing because you would normally have a 2-3 shift in that speed interval, the times achieved match EVO's 599 time of 3.9 sec and wallop the 575 time of 5.4 sec for the similar 60-100mph interval.

Yes Darth550 "You're right, 3" exhausts do blow hard." They will blow your blouses right off. And when I get my ECU's re-mapped by DMS or Powerchip I look forward to posting some accurate performance data on this thread.
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Not quite, I used 3rd gear only without a shift. As my car is a manual and 2-3rd is the slowest shift, I wanted an uninterrupted run up through the main power band for consistency and comparability. That interval is also easily correlated to any road test for 60-100mph. I did point out that if I was doing say 0-160kph I would have not shifted out of 2nd at 100kph and therefore that interval up to 160kph would have been increased by the time taken to shift. When I first got the car it did 4.5 sec with no cans, just the Tubi tips. Throw in a shift and it could be over 5 sec. Conversely, offsetting the shift time savings is the fact that I am starting the clock with the rpm at only 4,850 so that is a negative to performance. How much that loss compares to the shift time gain I cannot say. What the numbers do show is that apples to apples my car has improved from 4.5sec to 3.8sec with no tune optimisation for the bigger pipes. Both DMS and Powerchip quote roughly 40hp improvement on a stock 575. I am quite confident a tune from either will give double that with the 3inch pipes. I did also make two K&N air filters out of 3 550/456 filters. K&N don't make a 575 filter.

 

These are what came with the car. The car is actually ok inside it is probably too loud outside however. I have a couple of can styles to try, both 3inch in/out. I am also getting the Tubis enlarged to 3inch in with the same tips. I forgot to mention the overrun is fabulous. Mini explosions.

 

Barry,

All was well when the system was first installed however when it heated up it interfered with the manual gear shift linkage on the left side. I took it apart and using a ball peen hammer put a couple of small dents where I saw my heat tape had been rubbing. It was rubbing on the right side of the transaxle housing also. Not ideal but all was fine after that. The dents are small and the flow restriction must be marginal. There is enough room that a future cosmetic rebuild in those areas would have the pipes clearanced to allow for the expansion. I also am not that pleased with the slight lack of symmetry you can see in the under car image. Not bad for a 1st effort by my young stainless welder however. The whole system grows in length by around 10mm when hot. I guess I did a Ferrari with that primitive fix.

As the stock pipes have tin heat shields and I decided to play it safe and wrap the pipes after the resonators. There are no heat issues that I can see.

 

The welder insisted on using V-band connectors which give nil adjustment. The advantage when everything is right is that they stay that way. They also allow quick removal of the exhaust system or part thereof. I purchased extra flanges so that in 10 minutes I will be able to change from Tubi tips to a muffler and I am installing on the factory cans so in a pinch I can pass a noise test if needed. You can see the connectors clearly at the rear of the cat deletes. I have them over the axle and also at the rear. Also as the system becomes rigid when the clamps are tightened I did not need the hanger assembly at the front and it seems the next ones at the side of the transmission are not really doing much either now.

I sure hope you try the big exhaust and pass a few 599s on your track days.

 

No buzz saw, no drone. The noise is a deeper than it was, sounds like a bigger engine. It may be awhile before I can let you hear it, I am away until Sept so the 575 will be asleep by June. You can easily converse while cruising. When cold with the high idle it is unsociable, in my mind. That is why I am trying some small cans. As you all know, it is easy to control the sound with the right foot once driving. I start the 575 and leave as quickly as I can and keep the revs low in higher gears until warmed up, just like the bikes.

 

The headers would be the ultimate final stage improvement to a 3inch exhaust. They will not however do all they can if they have to push the exhaust through undersized pipes. The gain will be largely only from losing the restriction of the primary cats. To get the full scavenging effect of headers you need to free up your exhaust. You should enlarge the pipes first. No hot rodder puts headers on a car with a factory exhaust. I know your x-pipes are not stock however they no doubt are still only 2 1/4 inch. 3inch pipes have 78% more flow area than 2 1/4inch. However those lovely headers combined with 3inch pipes would result in well over 600bhp on a 575 and make it as quick as a 599, except of course a 599 with 3inch pipes.