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I'm loving that exhaust tone. It sounds like what I want: mostly bass notes. Did the resonator delete introduce any popping sounds? One of the main things I dislike about the Magnaflow kit for my LS is the excessive constant "popping" noise over 3000 rpm (but not backfire cackle, a constant noise consistent with engine speed)
I think I've finally found the right mufflers for me. Too bad the two LSes with the Mina setup have no available videos :/
I've kept the factory "resonator" in this custom 2.5" setup, it's seen in the top right corner of this pic, downstream of the "h-pipe", in the stock location...
THe resonators which I referred to as being deleted this year.
Are the custom 2.5" vibrant resonators, I placed in the stock cat location... When I deleted the cats last year, I wanted to control the noise, so I opted to place resonators in their place.
I year later, I removed those too, so now its "straight pipe" all the way to the stock resonator case...
The setup is deep and loud, but free of rasp and drone... idle and low load, its pretty quiet, romp on it, it gets loud...
Thanks. It looks like the LS gets a different type of resonator though. It uses 2.25" piping and the resonators are two individual cans with the H-pipe downstream. The stock STR system is 2.5"? What about non-Rs?
don't know about the non R's but i just went and measured the original pipes off my STR
and thay are 55mm O/D = 2.16'' !, thay are stainless and center resonator is a twin in / twin out sheared canister . as GT42r staited he has left the center resonator standard.
witch i guess steps down then back up again unless the mina rear boxes are standard size (55mm) ? then not back up again .
i went 2.5'' from the trans back will do the front quarter when the cats are poked !
i removed my center resonator and replaced it with a
2.5'' X pipe then into two step through 2.5'' glass pack resonators at the rear ,no actual mufflers to speak of.
it has a buet rumble and tone , sounds like a freekn race car above 3grand, quiet idle apart from on choke cold start. oh well the neighbors get to hear it warm up too , it pops and bangs on overrun up in the revs witch sounds awesome to me anyway.
no drone but does rasp between 2 and 3grand at full throttle witch id like to fix . can be avoided with under 3/4 throttle
other wise couldn't have got it better it has a real deep note and coupled with the eaton
screem its music !
Last edited by Datsports; Aug 5, 2015 at 01:53 AM.
was there mutch sound difference with and without the two front resonators ?
also what prompted you to remove them ? I'm guessing it was still too quiet ?
or the internals broke up ?
I'm pretty sure without cats mine would be too loud !
The stock resonator case inlet/outlets can fit 2.5" piping nicely, once you cut away the stock piping running in and out of them far enough...
Factory resonator case also acts as a larger cross-over tube, (i.e. like a H-pipe X-pipe), as from glancing at it's baffled internals, the two channels are 'joined' down the middle...
I removed the two smaller aftermarket stainless resonators I installed earlier, because for one thing, I wanted it louder, and I was getting a smell from the exhaust, that I thought could have been the resonator material burning up.
Well, after ditching the resonators, it didn't get much louder, if al all, and the smell was still mostly there (mixture of running no-cats stink, as well as oil consumption i reckon) Visual inspection of the resonators suggested they were fine, and seemed to have fared well being close to the exhaust manifold for about a year...
Overall, pretty happy with the sounds, but the stink of running no cats is getting old, so next round at the exhaust shop, I'll likely be putting in high flow cats again...
Or maybe I'll just sell the STR as-is, and tweak the next Jag in line...
GT42R, how do you reconcile the state of your exhaust system with the comment below from MoscowLeaper? Did you re-tune your ECU? What hapened to fuel trims? Do you expect possible detonation in hot weather? Have you noticed a reduction in mileage?
Originally Posted by MoscowLeaper
All of the extenders will cause a slow reaction of the O2S to the mixture change. It will hurt all of the transient conditions and it may lean a mixture in a cruising conditions (this will affect a milage, increasing a fuel consumption). Transition from a cruising to a power enrichmet will be affected too, it may cause a detonation (in a hot weather). Also, in some situations a EGT may rise too high, causing a damage to a cat converters and/or exhaust valves/seats.
The best way to fit a custom cats or to remove a cats is to flash a proper tune and leave secondary O2S in place.
All of that may be true, I haven't datalogged or tested close enough to say one way or another.
Although I keep my ear out for pinging, I haven't detected any. I do run 94 octane all the time though, which is even one step above '91 premium' available at the pumps here.
Fuel economy, I can't say for sure, because I don't drive the STR day to day, when I do take it out on weekends, I'm usually hooning on it all the time, so my average fuel economy is quite poor. Occasionally, when I am cruising on the highway, with the cruise set to 130-140km/h, the instant fuel economy gauge shows 7-8l/100km, so quite good imo, pretty much like stock, other operating conditions... hard to say...
Every time I've checked my long and short term fuel trims, they've always seemed low and reasonable, so nothing there to suggest any issues, but again, likely would need more datalogging to say for certain. Overall, she runs good, pulls strong, nothing seems amiss, would like to do some more reading and testing on how much the secondary o2's really effect closed loop performance though...
I will say this much though, running no cats has one major drawback, the smell/stink from cat-less exhaust is really unpleasant in an otherwise quiet luxury sedan...
It's therefore, really hard to justify not running some kind of catalytic converter, so all of these workarounds really shouldn't necessary in most cases...
I spoke with Eurocharged regarding a secondary o2 delete/disabling through their software, but haven't heard back... this era jag's not really super high priority on their development list...and it also leads one to ask how comprehensive is would their tune based o2 delete be, and how would it effect closed loop performance?
I've mostly wanted to get the right noise from my STR, and after several exhaust revisions and setups, I've got what I'm looking for... the o2 and cat setup isn't ideal though, but it's worked out fine for me thus far...
from what little I've read online on the topic, it seems the rear o2's can be responsible for fuel trims in closed loop, but their margin for adjustment is VERY very small... someone cited GM documentation suggest +/-1.0% authority, Ford +/- 0.5%, Toyota +/- 2.0%... seems negligble...
When I did my exhaust setup, I started with the X-pipe, high flow cats and resonator delete and it sounded extremely raspy. I ended up adding resonators and deleting the mufflers instead and it became quite loud, but the tone was far better.
Indeed, in my too-many-to-count exhaust revisions, I let the exhaust shop talk me into removing the stock resonator, against my better judgement... From the moment I fired it up, I knew it sounded like ****! Went for a spin around the block... Promptly returned to tell them to put it back in...
Keeping the factory resonator case on is probably one of the best aspects of my exhaust setup... it supports 2.5" in/out as well, so really no good reason to get rid of it! It also acts as a 'cross-over' down the full inner-length, so that helps with tone as well no doubt.
That "line of Jags" video was GREAT!!! In the early '90's, anything close to Hunter Green was popular. That Aspen Green really pops, as does the condition of that ST-R. Good Show!
BTW, your suspension was so smooth, you didn't need a steady cam! Nice to see a F-type in your rear-view. Worthy of a Top Gear segment!!
Last edited by Warspite; Sep 1, 2015 at 09:42 PM.
Reason: Spell Check is your Friend
Hi Warspite, thanks for the kind words, The footage is very smooth indeed, thanks mostly to the amazing image stabilization system of the Sony Action Cam I use to record the drive...
Regarding your exhaust questions. There was a bit of discussion regarding just that, in details, a few posts up from this one, so read back in this thread a little to answer your questions,
But to put it simply, no CEL's or problems passing emissions, or performance issues, with the exhaust setup as it currently stands, which is, no catalytic converters, straight pipe exhaust.
I have 'spacers' on the stock secondary o2 sensors, in order to fool the computer into thinking the cats are still in place. Works good.
Hi Warspite, thanks for the kind words, The footage is very smooth indeed, thanks mostly to the amazing image stabilization system of the Sony Action Cam I use to record the drive...
Regarding your exhaust questions. There was a bit of discussion regarding just that, in details, a few posts up from this one, so read back in this thread a little to answer your questions,
But to put it simply, no CEL's or problems passing emissions, or performance issues, with the exhaust setup as it currently stands, which is, no catalytic converters, straight pipe exhaust.
I have 'spacers' on the stock secondary o2 sensors, in order to fool the computer into thinking the cats are still in place. Works good.
Ingenious workarounds! And they paid off (I admit playing that video at least 3 times, which is why I missed some of the write ups). Thanks for sharing!
Just to clarify, that 'workaround' will only be necessary if you remove the catalytic converters.
Other exhaust work such as larger diameter piping, resonator delete, X-pipe install, muffler change or delete, won't require any special changes, and won't set off any codes.
Despite having done the cat delete myself, I am going to be re-installing the cats again soon. The smell from the exhaust without them is unpleasant, and anyone following you in traffic can definitely detect your missing cats... Not a mod I would recommend to be honest...
