[Akura]

Hello all,

Well, it´s time to do some mods to my 2018 ZL1 (6k miles)...

First, let me tell you: I am in Madrid, Spain, and here we have state inspections very similar to California, as I´ve read here, and the big problem is they include a smog test. Too, our gas is your 91 or 93 oct, no way to find (and use) E85, Meth, Racing fuel...

What I mean about the smog test? Well, there´s no option to remove cats or axle back (this one can be replaced, not removed), and the police can "escort" you at any time to pass an extra inspection if they have suspicion you removed smog parts... so no way to use the car without cats (e.g.) thinking to add them just to pass the programmed inspection (we pass them first after 4 years, next twice each 2 years and lastly each year).

I´ve read a lot of mod threads, but quite all talk about packages who include lot of thinks I can´t do to my car, so knowing all that I told you before, I need advice about...

- what I am (quite) sure we can do:

• Catch can: Elite E2x installed with 2k miles.
  
  
• CAI: Roto-Fab or Roto-Fab Big Gulp? I am sure my prep is going to be small compared to all that you can do in the USA, this is why I am not sure if the BG is going to be more beneficial VS the normal one, or not.
  
  
• Ported TB: Tony Mamo? JDP? Katech? OEM or a big one? The blower is not going to be upgraded to a big one, at least for now...
  
  
• Pulley: If I change it is supposed to add more HP & TQ, but, in all RPM range? I mean, like big turbos, small pulley will decrease power at low RPMs and increase it at high ones? Which one do you recommend? I always read about upper one... what about the lower? And belt?
  
  
• Tune: I will need to search an American tuner who will be capable to tune the car "remotely" altogether with a Spanish one and his dyno.

- what I am NOT sure we can/need to do:

• Axle back: Will I see HP & TQ improvements changing it? The car is VERY loud compared to the rest of cars you usually see here, so making more noise is secondary to me.
  
  
• Headers: Replacing them will affect the smog test? I am not sure if they eliminate the firsts cats or not, and the rest of the exhaust wouldn´t change, so...
  
  
• Cooling: Will I needed to change thermostat and heat exchangers (like Weapon-X triple kit) with this modest prep?
  
  
• Spark plugs & wires: Same question as above (Brisk or others).

More ideas? All your comments are welcome, thank you!

[Akura]

80 reads, 0 replies, great members...

[Gbrownzl1]

Do you have to pass a visual or just emissions test? In my gt500 it would still pass California smog with a pulley, intake, throttle body and tune. Just make sure whoever's doing your tuning does not turn off your rear o2 sensors.

[2ltrgsr]

Originally Posted by Akura

Hello all,

Well, it´s time to do some mods to my 2018 ZL1 (6k miles)...

First, let me tell you: I am in Madrid, Spain, and here we have state inspections very similar to California, as I´ve read here, and the big problem is they include a smog test. Too, our gas is your 91 or 93 oct, no way to find (and use) E85, Meth, Racing fuel...

What I mean about the smog test? Well, there´s no option to remove cats or axle back (this one can be replaced, not removed), and the police can "escort" you at any time to pass an extra inspection if they have suspicion you removed smog parts... so no way to use the car without cats (e.g.) thinking to add them just to pass the programmed inspection (we pass them first after 4 years, next twice each 2 years and lastly each year).

I´ve read a lot of mod threads, but quite all talk about packages who include lot of thinks I can´t do to my car, so knowing all that I told you before, I need advice about...

- what I am sure we can do:

• Catch can: Elite E2x installed with 2k miles.
  - No problem here.
• CAI: Roto-Fab or Roto-Fab Big Gulp? I am sure my prep is going to be small compared to all that you can do in the USA, this is why I am not sure if the BG is going to be more beneficial VS the normal one, or not.
  - Unless you are going with a 103TB... normal Roto-Fab is fine.
• Ported TB: Tony Mamo? JDP? Katech? OEM or a big one? The blower is not going to be upgraded to a big one, at least for now...
  - Tony Mamo is what I went with... Katech is solid as well.
• Pulley: If I change it is supposed to add more HP & TQ, but, in all RPM range? I mean, like big turbos, small pulley will decrease power at low RPMs and increase it at high ones? Which one do you recommend? I always read about upper one... what about the lower? And belt?
  - I took the route that Lingenfelter did with there "720 Kit". Look it up! ( Lower pulley/balancer/belt/plugs )
• Tune: I will need to search an American tuner who will be capable to tune the car "remotely" altogether with a Spanish one and his dyno. - I would use Jannety, PAT G or Chris Crawford for the remote tune.

-

- what I am NOT sure we can/need to do:

• Axle back: Will I see HP & TQ improvements changing it? The car is VERY loud compared to the rest of cars you usually see here, so making more noise is secondary to me.
  - this won't impact emissions.
• Headers: Replacing them will affect the smog test? I am not sure if they eliminate the firsts cats or not, and the rest of the exhaust wouldn´t change, so...
  - Unless you are doing the green cat option I would leave this alone for now. The big issue with doing the pulley mods is the increase in blower heat and the issue of the CATs not holding together over time. The green cats will be your best bet for longevity as long as ou don't go wild with a bigger blower.
• Cooling: Will I needed to change thermostat and heat exchangers (like Weapon-X triple kit) with this modest prep?
  - I'm not drinking the Kool-Aid on the need for oversized heat-exchangers unless your tracking the car and plan to throw ice in a oversized expansion tank...or going the a/c chiller route. It's not needed for a street car on the road that's not going through the paces.
• Spark plugs & wires: Same question as above (Brisk or others). -answered above in pulleys... but 7 range plug when you go up in pulleys.(NGK 6510 LTR7IX-11 )

More ideas? All your comments are welcome, thank you!

answered above... pm me any questions you might have on those responses.

[BMWM.D.]

Originally Posted by Akura

80 reads, 0 replies, great members...

In all honesty, I think only you can answer this. Smog laws differ drastically by state here in the US, so I feel we can only guess as to what you can or can’t do in Spain.

Here in California, you really aren’t allowed to do anything that doesn’t have a CARB certification. An axle back exhaust is about it legally. We no longer have the tailpipe emissions testing here though, so it’s just visual and an OBD2 monitor check. An intake is a definite fail, and I’m pretty sure a modified PCV system (catch can) will do the same. Some counties in CA still do a tailpipe emissions test on a dyno, so that changes things. See why this is tough?

I know in states like Texas, they just do a visual to make sure you have cats on the car. They don’t care if you have headers, aftermarket cats, etc. In CA, you can’t relocate cats or swap them out for high flow models.

You really need to figure out what exact testing they do in your city, how they inspect the car (on a lift or not), and if CARB certification is required on parts.

[Markoz28]

As others have mentioned, it will be difficult to determine the emissions part. Other than that I went with RT intake, TM TB, kooks 2” headers with no cats (bc I can), and 9.17 lower pulley. Car still needs a retune as the previous tuner left a lot on the table. But so far the car is much faster and I don’t have any problems with heat that I can see. I do let the car cool down about 30-45min between 1/4 mile runs. If I was doing track racing than I would consider the interchiller over larger heat exchangers. I just feel there is more benefit to that. As far as remote tuners, as previously stated Jannetty racing and Pat G can set you up nicely.

[SJFGTO]

Without knowing more specifics about your smog laws everything is just a guess, but here are my 2 cents: 1) roto-fab is likely ok (mostly for looks/avoid the big gulp version as you don't need it), 2) catch can may be fine, it does technically alter your emissions system slightly and it is debatable whether you need one 3) a TB is likely ok, either name you mention is a good one 4) avoid the pulley unless you are going to add long tube headers, which in turn will require a tune. Headers and green cats may or may not be ok, you would need to know specifically whether removing factory emission control devices like cats is ok if replaced by an approved after market equivalent. A tune will certainly impact emissions and may or may not be a good idea depending on whether your vehicle is tested and the type of test. Good luck!

[Akura]

Originally Posted by Gbrownzl1

Do you have to pass a visual or just emissions test? In my gt500 it would still pass California smog with a pulley, intake, throttle body and tune. Just make sure whoever's doing your tuning does not turn off your rear o2 sensors.

Hello & thank you.

Just emissions test, and as I’ve read is similar to your “basic test”, first at idle and next running at 2500 rpm. The CO2 has to be less than 0,3% and the lambda between 0,97 and 1,03.

Don’t turn rear O2 sensors... got it!

[Akura]

Originally Posted by BMWM.D.

In all honesty, I think only you can answer this. Smog laws differ drastically by state here in the US, so I feel we can only guess as to what you can or can’t do in Spain.

Here in California, you really aren’t allowed to do anything that doesn’t have a CARB certification. An axle back exhaust is about it legally. We no longer have the tailpipe emissions testing here though, so it’s just visual and an OBD2 monitor check. An intake is a definite fail, and I’m pretty sure a modified PCV system (catch can) will do the same. Some counties in CA still do a tailpipe emissions test on a dyno, so that changes things. See why this is tough?

I know in states like Texas, they just do a visual to make sure you have cats on the car. They don’t care if you have headers, aftermarket cats, etc. In CA, you can’t relocate cats or swap them out for high flow models.

You really need to figure out what exact testing they do in your city, how they inspect the car (on a lift or not), and if CARB certification is required on parts.

Thank you very much. About the exhaust system, the only modification allowed is to change the axle-back, except if it modifies smog test results (this include letting cats quiet...), but I can play a card: this car is not sold in Spain, so inspection guys can’t compare the car to others

Originally Posted by Markoz28

As others have mentioned, it will be difficult to determine the emissions part. Other than that I went with RT intake, TM TB, kooks 2” headers with no cats (bc I can), and 9.17 lower pulley. Car still needs a retune as the previous tuner left a lot on the table. But so far the car is much faster and I don’t have any problems with heat that I can see. I do let the car cool down about 30-45min between 1/4 mile runs. If I was doing track racing than I would consider the interchiller over larger heat exchangers. I just feel there is more benefit to that. As far as remote tuners, as previously stated Jannetty racing and Pat G can set you up nicely.

Thank you very much too! About the interchiller, like this one?

https://www.cspracing.com/forced-ind...ler-universal/

Where do you install it? Seems big...

[Akura]

Originally Posted by SJFGTO

Without knowing more specifics about your smog laws everything is just a guess, but here are my 2 cents: 1) roto-fab is likely ok (mostly for looks/avoid the big gulp version as you don't need it), 2) catch can may be fine, it does technically alter your emissions system slightly and it is debatable whether you need one 3) a TB is likely ok, either name you mention is a good one 4) avoid the pulley unless you are going to add long tube headers, which in turn will require a tune. Headers and green cats may or may not be ok, you would need to know specifically whether removing factory emission control devices like cats is ok if replaced by an approved after market equivalent. A tune will certainly impact emissions and may or may not be a good idea depending on whether your vehicle is tested and the type of test. Good luck!

Thank you vey much too.

RF mostly for looks? Do you think is not necessary for a tune?

...avoid the pulley unless you are going to add long tube headers - Why? I’ve read lot of mods threads doing upper pulley without touching headers

[Akura]

Originally Posted by 2ltrgsr

answered above... pm me any questions you might have on those responses.

Thank you very much too! Be sure I will pm you tomorrow, thank you again!

[Akura]

Here 2ltrgsr & Markoz28 are talking about lower pulley, but I’ve read a lot (and saw videos) about uppers, like this one:



What is the difference? Can be upgraded upper & lower at the same time? Thank you.

[Markoz28]

Upper plluey is less expensive but more involved on the install. Now if you were going to port the supercharger than I would go with the upper instead of lower for sure. Porting the SC and doing a 2.3 or smaller pulley would build some good power. I still think headers would needed but not sure.

[BlaqWhole]

Originally Posted by Akura

80 reads, 0 replies, great members...

Well it was a long post. And you asked every question that has been answered countless times. So yea we are great members here. But a quick search or a call to a shop could have given you all the info you need. To answer tho...

Catch can - Lots to debate about this. If you ask me, save your money. That is the unpopular opinion. But I've had plenty of cars all that never even seen a catch can before. And they all went to well over 100K miles. I doesn't add HP. It won't have any effect on engine longevity. It isn't required by smog laws. So for me there is no point to spending money on one. But I'm not telling you not to get one. If you just have to have one, then knock yourself out.

CAI - If you're getting a tune then you might as well go ahead and get an intake that requires a tune. If you're staying non-tuned then a standard cai is fine.

PTB - They're all just ported stock units. They do a little and they're nice to have. Pick whichever one you fancy. IMO they all are decent units. I have a Katech PTD and I like it.

Pulley - This adds boost so you will see increased HP and TQ everywhere in the RPM range. The best bet is to get an upper one and speak with your tuner on which size to go with. Too small and you'll have issues with overheating so be careful of that. Plus you don't wanna waste money on pulleys and tunes if you're just gonna swap out the blower at some point anyway. That would be a waste of money. So figure out if you wanna go that route or if you would prefer to do a blower swap.

Tuner - There are dozens of good tuners. Pick one and look for reviews on their work.

Axle-back - At what they cost, if you ask me I say just get a cat-back. It'll save some weight and give you a better sound. Try to find one that has a sound that you like. And one that fits your budget as they can get very expensive.

Headers - You will have to remove the stock cats. But if it matters to you then get a HF catted setup. Make sure it is legal where you are. And there are lots of good brands in all price ranges. TSP will be the cheapest and they are good quality. ARH and Kooks are the most expensive but the quality is second to none.

Cooling, spark plugs, wires - Go with the tuner's recommendations.

What you should do is prepare a list to ask tuners and email them or call them. They will put together a package for you when you're ready to buy. That is your best bet for now. In the future you can go wilder if you want. But I say for now keep things simple.