rotarymike

iTrader: (4)

Actually, when I was looking, there was a VR 6MT sedan in Atlanta. Had over 100k miles and still over $20k, and red isn't my thing.

Bear in mind that mine are Florida-dark which IIRC isn't legal anywhere else but southern border states (TX, NM) although they may have changed. Heck, it might even be not legal for FL. Previous owner and all. I just auto-rolldown all my windows if I get pulled over... not that that has happened in this car. Yet.

As far as the grill, I'd think long and hard about buying one on ebay or amazon that's already black, rather than painting over the chrome. Without a really good etch, the paint will come off through wind abrasion from driving. Sand, stones, dust at 80mph, etc. With too good an etch, the plastic will soften and that's a different problem...

BoomerSpeed01

When I painted the grill and trunk lip on my coupe a year ago, I just lightly sanded them down with some 200 grit. Just enough to give the surface some texture for the primer to stick to. I didn't get to see the longevity of the results though, because it was totaled around a month later by someone hitting it when it was parked..... But like I mentioned a few posts back, it looked very good when I was finished.
If you seriously think it's that big of an issue, I may consider getting a 2nd grill.

backman_66

Warning, this will be a long post, lol. I'm bored at work today. I just want to chat a little about my upcoming plans for 2021 - 2022. The next mods I'll be doing to my car are some visual stuff in the next month or so. I'll be getting window tint and chrome window trim delete done, and a CF trunk spoiler.

But after that, I'm back to doing performance-oriented stuff. This is where I'm having a hard time deciding what to do, in which order.

1. "Fixing" my exhaust. Currently I'm using AAM RHFCs that are 2.5" but they're mated to a 2.25" Q300 CBE. I really don't like the step down in piping because it's not a smooth transition. I know that exhaust gases in this area close to the engine have a fairly significant effect on scavenging. It continues to bother me that there's this lip where the flanges meet. I am kinda OCD and i know it's robbing me of some power, even if it's just a few HP. I do plan to dyno my car this year and I want every bit of power I can make. I want to get this fixed by buying something like this: https://www.ebay.com/itm/13309698544...kcid=28&chn=ps

I would have that piece cut in half. Then I'd have a muffler shop cut off the flanges on my Q300 and replace it with the pieces that I cut in half. They would use a pipe expander on the Q300 piping to bring it up to 2.5" so it could be welded to this replacement flange. I have thought a long time about this and I have tried to find other ways to get this done, but I think this is the easiest / cheapest solution..

Along with that, I want to try replacing my Q300's mufflers since they are chambered and restrictive in comparison to a more straight-through design. That's why I have been eyeing twin loop mufflers. It may sound rice because they're almost exclusively used on Hondas, but a muffler is a muffler and if it works, then I don't care what car it's on.

The purpose of the twin loop design is to have the exhaust pass through the muffler twice. The internal piping is perforated. These mufflers are supposed to maintain good low end torque and be quiet in the lower rpm's because the exhaust will mostly pass through the chamber twice. But whenever you go WOT, the increased pressure and exhaust flow would allow some of the gases to pass through the chamber only once, since some of those gases will be spilling over to the outlet pipe without passing through the loop at all. I hope that makes sense. It feels like the best of both worlds to me because I want a muffler that can maintain a level of quietness but also not be as restrictive as a full chambered muffler.

Here's another way that someone explained it: "The loop design produces additional backpressure at lower rpm's to boost torque and whp production. This occurs because the exhaust flows following the loop and because the sound pulses are then almost 180degrees out of phase within the muffler, the perforated cores allow the out of phase sound pulses to cancel each other, this is why the loop muffler is so quiet. At higher rpm's and exhaust flow part of the exhaust still flows following the loop path, but a fair percentage also flows from one perforated core to the other core greatly reducing the backpressure (also pulses are quieted due to phasing again) and produces greater whp than a typical fartcan like HKS, DC sports etc."

I'm planning to buy one of these mufflers as a "test" soon: https://www.summitracing.com/parts/xfo-s12r-2-25
It's overall length is about 20-21" and the Q300 muffler is about 22" from my measurements, so it should fit pretty well. If it's too loud after testing, then I'll just resell it for a loss or put it on my Chevy Cruze lol (it doesn't even have a visible muffler tip in stock form - I hate that!) Earlier I said I want to dyno my car this year. Well, I want to dyno it before / after I change these mufflers so I can see if there is any improvement. I planned to dyno it regardless so I might as well test an upgrade while I'm at it. I'm really hoping to gain about 5whp+ because my car is pretty heavily modified and I should be pushing through more exhaust flow compared to stock, and 2.25" piping is fairly restrictive anyway. Anything that can lessen the backpressure is going to help.

2. z1 two piece rotors. I have a $300 credit on the z1 store and I plan to get new pads + rotors this year. I want to gain some performance while changing them. I originally planned to do these first before exhaust fixes, but it's just so hard to bite the bullet and spend $1,100 on rotors... and even more since I'm including pads and brake fluid! whewwwww....

3. Clutch, lightweight flywheel, CMAK, and 4.083 gears. These are going to be some of my final modifications and then I'll pretty much consider my car "complete." I really, REALLY dislike how the car feels with the stock dual mass flywheel and long gearing. Even with all of the performance mods I've done, it still feels so SLUGGISH sometimes due to the stock drivetrain. My previous car was an RSX-S with 5.062 gears and it was so dang fun. I want to wait until my clutch / or slave cylinder (its the slave, right?) starts going out more before I consider these mods though. It's not going to be cheap either.

So that's my discussion for the day.

EDIT: Oh yeah, I want to get an OEM front sport lip eventually too. That will probably be the last thing I do. Yeah...

Rochester

iTrader: (9)

Lots of stuff to process. How about we take your newbie thread and move it to the Build threads, and you go to town? Or start a new one on your own?

backman_66

Build threads intimidate me. I don't really want to "commit" time to a dedicated thread for my car, I guess. But you're the moderator so whatever you feel is best.

rotarymike

iTrader: (4)

thought for the exhaust: instead of working and potentially cracking the Q300 piping.

Z1 rotors - A. Wait for black friday or another big sale if you can and B. consider fronts only, if you're after bang-for-the-buck weight savings and braking increase.

rotarymike

iTrader: (4)

It isn't that bad - think of it more as a collection of thoughts than a set-in-stone list.

backman_66

Yeah I've thought about using those too. But it's more money to buy that piece instead of just using an expander on the existing pipe. Have you done pipe work before? Is there a risk of actually cracking the piping by using that method?

Rochester

iTrader: (9)

You alluded to plans for at least the next two years, and bought a fantastic car from jsolo. I think you need a build thread.

Intimidated? You're 71, for crying out loud. That's two moderators making the suggestion. Man up and step up, boss.

You've experience and you write well. Whatever you do will be a good read, I'm sure.

rotarymike

iTrader: (4)

I've always had issues with pipe expanders cracking steel pipe - they're meant to expand one pipe just enough for a slip fit over a pipe of the same size. So maybe 1/8, not 1/4. In addition, the more you stretch the metal, the thinner it gets, so it can lead to cracking later from flexion stress.

Personally, I'd have them cut off the last bit of pipe for the Q300, jig up the transition, and weld it and a new flange on the end. With a skilled welder maybe 20 minutes per pipe, including making the jig?

OR, or, just follow with me here... since you're considering changing the whole thing anyway, why not either buy what you want (or have the whole thing 2.5" custom made by a muffler shop) and resell the Q300s intact?

backman_66

Lol does my profile say I'm 71 years old? 😅

I'm actually 34! I guess I can work up a build thread sometime.

2.2Lude

iTrader: (1)

lol I say do it too, you’ve provided lots of useful information for the community with 370z springs already so I’m sure people want to follow your “build”.

I also agree with rotary about getting 2.5” flanges and having a reputable exhaust shop cut the 2.25” flanges/some piping off the q300 and use a 2.5->2.25 transition rather than expanding pipe. Might be a little more expensive but it’s a better end product.

Too lazy to go through and find exactly what your plans were in regards to the q300 piping coupled with the twin loops, might be easier if you had a..build thread..lol

Rochester

iTrader: (9)

Right. Fix that please, or just remove the birthdate, that's fine too.

Then create a build thread, we'll all subscribe, and all will be right with the world. Off you go now.

backman_66

I've asked FI, tried to contact hall built multiple times, and I don't trust local shops to build me a custom exhaust. FI refuses to use any muffler besides their own. HB doesn't reply. So I don't think a full 2.5" exhaust option is in my future.

rotarymike

iTrader: (4)

I do feel your pain; I went with FI partially because of reviews and partly because no one around here impressed me much.

Have a local shop show you pictures of previous builds (hint: you want to see mandrel bends welded in, not crush-bent tubing). If they don't have a picture book of previous custom builds, walk away.

Find out where the local GM/Ford guys get their exhausts made - custom is way more of a thing with domestics. My friend who has an older CTS-V got a piece of freaking art for like $1200... that's 3" headers back to tips. Commercial 3" exhausts are like $4k and up...