Exhaust System Upgrade Options Available for Turbo I4 AMG Engine Yet?

[F1 SML8R]

You’ll probably need to get the exhaust valve re calibrated at Lotus if you change the exhaust. The valve is super sensitive to the slightest difference in the open and closed position. I had CEL after changing my I4 Exhaust, after recal, no problem.

I am curious about this and will report back. If you go through all of the exhaust posts, it seems that it was a few early cars that had this issue. However, later designs on several different exhausts and perhaps a loosening of the calibration from Lotus have contributed to not hearing about this anymore. I'll certainly post here as soon as it's installed, with pics and if I had any dash warnings.

 

[lynchy73]

What does this mean exactly and how do they do this

It’s just a page in the Lotus diagnostic software. They go to the page in the Lotus software, select the exhaust valve calibration and press go. The valve goes to full open, full closed and the car learns the new open/closed positions of the valve. That’s it, very simple with the correct software.
I believe the Milltek Exhaust valve controller avoids throwing codes.
I have a V1 Ti Aerie I4 exhaust. The valve arrangement is actually designed to match the OEM Valve’s open/closed positioning, but it still threw codes. Only the recalibration resolved it, no problem since. I also have their sports cat.

 

[lynchy73]

I am curious about this and will report back. If you go through all of the exhaust posts, it seems that it was a few early cars that had this issue. However, later designs on several different exhausts and perhaps a loosening of the calibration from Lotus have contributed to not hearing about this anymore. I'll certainly post here as soon as it's installed, with pics and if I had any dash warnings.

I think a lot of people also use the Milltek valve controller when they do an exhaust. Apparently the V2 Aerie is better regards not throwing exhaust valve codes, however the system is super sensitive so don’t be surprised if it does. Just get the valve recalibrated if it does happen, or run the Milltek, although personally I think the recalibration is no harm, as you know then it’s right (not being masked by the Milltek).

 

[F1 SML8R]

Agree, I definitely prefer the OE functionality.

 

[F1 SML8R]

So my exhaust got installed today (Quickjacks, me, and my buddy) and man it was work. More importantly, fired it up and drove around the block all good. Then after a few minutes on the highway, engine light! So, I guess the calibration is going to be needed. The good news is it's going in Monday for an oil service (1100 miles, need to get any micro metal out), software updates and I'll mention the calibration needed. I'm hoping they do it as part of the software update and there's no charge. Pics to follow, stay tuned...

 

[F1 SML8R]

Ok, besides having to now have the valve calibrated that @lynchy73 and others have mentioned, it’s important to note that doing this on quickjacks, is a pain. I would say if you have access to a lift, use it!

First obstacle, the OE i4 exhaust is big and has an additional mounting bracket dead center. See pic…

Next problem, the OE decat pipe (no third cat on i4) has a spot weld that unfortunately goes through the pipe making it essentially un-removeable. See pic…

Now next problem, because we couldn’t remove the decat, we couldn't squeeze the exhaust out. So after an hour of twisting and turning, I made the call. Reciprocating saw! See pic…

After that, getting it out was a cinch! Oh yeah, I skipped one other big headache, the V band clamp around the down pipe and decat. Getting that off was super hard because of the placement of the bolt. I don’t know how many extensions, elbows, etc. we used, but we finally broke it loose.

All in all, it was cool we did it, but it was a pain. BTW, you if you watch the cool install video on one of the other threads for the GRP titanium v6 exhaust install, it seems straight forward. However just know that the i4 is at another level of complexity if you don’t have a lift, the V band clamp on the down pipe to decat connection access, the spot weld that went too far on the decat preventing its removal, and finally the center bracket that got in the way of removal because the OE box is so big.

Lastly, as a reminder I got the v2 and it is beautiful(see pics earlier in this thread), even more so after a little blood (knuckles were busted), sweat and ok maybe one tear of joy when done!

 

[MB-SC-LTSE]

Ok, besides having to now have the valve calibrated that @lynchy73 and others have mentioned, it’s important to note that doing this on quickjacks, is a pain. I would say if you have access to a lift, use it!

First obstacle, the OE i4 exhaust is big and has an additional mounting bracket dead center. See pic…View attachment 63324
Next problem, the OE decat pipe (no third cat on i4) has a spot weld that unfortunately goes through the pipe making it essentially un-removeable. See pic…
View attachment 63325
Now next problem, because we couldn’t remove the decat, we couldn't squeeze the exhaust out. So after an hour of twisting and turning, I made the call. Reciprocating saw! See pic…
View attachment 63326
After that, getting it out was a cinch! Oh yeah, I skipped one other big headache, the V band clamp around the down pipe and decat. Getting that off was super hard because of the placement of the bolt. I don’t know how many extensions, elbows, etc. we used, but we finally broke it loose.

All in all, it was cool we did it, but it was a pain. BTW, you if you watch the cool install video on one of the other threads for the GRP titanium v6 exhaust install, it seems straight forward. However just know that the i4 is at another level of complexity if you don’t have a lift, the V band clamp on the down pipe to decat connection access, the spot weld that went too far on the decat preventing its removal, and finally the center bracket that got in the way of removal because the OE box is so big.

Lastly, as a reminder I got the v2 and it is beautiful(see pics earlier in this thread), even more so after a little blood (knuckles were busted), sweat and ok maybe one tear of joy when done!

Would like to hear your thoughts about the sound difference after vs. before, and if you could upload a short video so we can hear it would be awesome.

 

[Lotus F1]

I guess the big question was it worth the effort and the cost

 

[F1 SML8R]

It was worth it, but man it was definitely work! I'll try top grab a video of it in a bit.

 

[F1 SML8R]

Would like to hear your thoughts about the sound difference after vs. before, and if you could upload a short video so we can hear it would be awesome.

Video will follow shortly. I will say the sound change is more about deeper tone than overall increase in volume. However, on the road you really hear it under open throttle. Also, the exhaust creates a lot more pops and burbles which give it a bit more character. For me , the OE exhaust even in sport mode just seemed way too quiet.

 

[TurboTambo]

Ok, besides having to now have the valve calibrated that @lynchy73 and others have mentioned, it’s important to note that doing this on quickjacks, is a pain. I would say if you have access to a lift, use it!

First obstacle, the OE i4 exhaust is big and has an additional mounting bracket dead center. See pic…View attachment 63324
Next problem, the OE decat pipe (no third cat on i4) has a spot weld that unfortunately goes through the pipe making it essentially un-removeable. See pic…
View attachment 63325
Now next problem, because we couldn’t remove the decat, we couldn't squeeze the exhaust out. So after an hour of twisting and turning, I made the call. Reciprocating saw! See pic…
View attachment 63326
After that, getting it out was a cinch! Oh yeah, I skipped one other big headache, the V band clamp around the down pipe and decat. Getting that off was super hard because of the placement of the bolt. I don’t know how many extensions, elbows, etc. we used, but we finally broke it loose.

All in all, it was cool we did it, but it was a pain. BTW, you if you watch the cool install video on one of the other threads for the GRP titanium v6 exhaust install, it seems straight forward. However just know that the i4 is at another level of complexity if you don’t have a lift, the V band clamp on the down pipe to decat connection access, the spot weld that went too far on the decat preventing its removal, and finally the center bracket that got in the way of removal because the OE box is so big.

Lastly, as a reminder I got the v2 and it is beautiful(see pics earlier in this thread), even more so after a little blood (knuckles were busted), sweat and ok maybe one tear of joy when done!

I never had any trouble taking the OEM exhaust out, but I did change the downpipe at the same time so that probably gave more space. The hardest part was getting the new one in and lined up. A days jobs all up. But worth it.

 

[F1 SML8R]

@TurboTambo Yup, the V clamp on the downpipe was very problematic. Thinking back now, I might have been able to get to the bolt via the access panel in the trunk like one would for the downpipe, but we never even thought about it given we were only working on the exhaust. That's why I mentioned the GRP v6 titanium install video appears so straight forward. They were working with simple flat flanges and easily accessible bolts. Just not the case for the i4. I just felt compelled to explain it so people know what they are getting into on the i4 version.

 

[Lotus F1]

Video will follow shortly. I will say the sound change is more about deeper tone than overall increase in volume. However, on the road you really hear it under open throttle. Also, the exhaust creates a lot more pops and burbles which give it a bit more character. For me , the OE exhaust even in sport mode just seemed way too quiet.

Well that's good to know I guess the benefit is that it's lighter as well but I'm not really interested in a deeper tone to be honest. I like the higher pitch sound

 

[F1 SML8R]

Here's the quick video. first part is just a cold start in touring until idle warm-up completes and drops back down to normal touring idle. Then you get two throttle blips in touring. Then I switch to Sports with two throttle blips there. Then I switch to track mode with two throttle blips there. Lastly, I drop back to touring before shutdown.

 

[Lotus F1]

I don't know maybe it's just that it's not the same in person but it sounds kind the same as stock.

 

[F1 SML8R]

Definitely better than stock. I probably should have recored a base video with the stock exhaust installed. I agree, the video isn't representative of in-person perspective.

 

[Milk242]

Damn, I was thinking about tackling this install myself when I get back to the states, maybe i still will since removing the downpipe seems to provide better access to some of the exhaust specific clamps.

 

[Lotus F1]

I'm thinking about just doing the downpipe and I have the performance catalytic converter and see where that lands me

 

[F1 SML8R]

That should definitely increase volume. The downpipe is a major bottleneck.

 

[TurboTambo]

@TurboTambo Yup, the V clamp on the downpipe was very problematic. Thinking back now, I might have been able to get to the bolt via the access panel in the trunk like one would for the downpipe, but we never even thought about it given we were only working on the exhaust. That's why I mentioned the GRP v6 titanium install video appears so straight forward. They were working with simple flat flanges and easily accessible bolts. Just not the case for the i4. I just felt compelled to explain it so people know what they are getting into on the i4 version.

It's not easiest of exhaust installs. Definitely need a few skills up you sleeve to fit this one.