Suggestions for long highway cruising mods
 

I have a 2013 mt with 23k miles. While I love the car as a commuter for half hr drives I am now facing the possibility of driving 1 hr each way on the i95 for a contract job.


I've been thinking about things I could change/swap to the car to help with the 80mph 1hr commute each way.


First thing that came to my mind was swapping the rear diff to lower the rpms overall so that the engine doesn't stay past 3.5krpm all the time. This will help a lot with gas too I suppose. I really only care about the long distance cruising and I realize my stand still acceleration will get worse with such a diff but it is not a problem as I really don't race on the streets with this car.



Second thing was a good set of coilovers that can be adjusted for a softer ride during the week.


Third would be wheels/tires , probably 18's with a good thread wear tire and low road noise? any suggestions here


I think the stock brakes are good for now since I don't really track the car.


Was thinking about sound deadening but haven't seen many threads about it.


The sound system on my car has been upgraded to an android radio with wifi hotspot so I can use kodi, Pandora etc etc so this is not an issue.




Would like to hear your thoughts. Especially the people here that commute long distances at such speeds.

Reply in red

If you have two hours of commuting at 80mph daily and you are talking about modding your car to make the commute easier, you bought the wrong car - plain and simple. Your best bet will be to get a second car like a Camry or something that is meant for doing that.

If you want a softer ride, put 16 inch rims on with some high sidewall tires. The bigger the sidewall, the softer the ride will be. Sound deadening is nice if you do it right and can be very expensive (dynamat is expensive, even if you DIY). Dynamat is always nice and rims can be swapped out in 15 minutes so you can have fun on the weekends.

I think you bought the wrong car if you can't even stand it for 1 hour trips.

I'm considering a contract job (1yr) and atm my car is almost paid so I don't wanna buy another car. My normal commute is 25-30 mins each way and the car has very low mileage for being a 13' model.


My warranty is actually 7yrs/100k so I would like to put some more miles into the car and not fall victim to the system of trading in getting ripped off and buying a sedan.


With a couple of changes here and there I think I can make it work with this car, after all I'm getting 2.5x the salary so it is something worth considering.

I never said I couldn't stand 1 hr trips. I only want to spare the engine a LOT of damage from driving at high rpms while cruising 80mph. It is in the 1st post man.

What are you driving at 115mph for hours on end? the car runs at like 3.5k at 80ish. that's normal for a car lol

I never said to get rid of the FR-S, I said to buy a second car for your long commute. If your FR-S is almost paid off, get a used sedan that is meant for long trips at highway speeds. You are not looking at small changes "here and there", you are looking at at spending $4-5k on mods plus install to make your commute easier - you can buy a second car for that price.

BTW cruising at 80mph for an hour each way isn't going to hurt your car at all.

You obviously never commuted on i95 in FL :P


Min Speed here is like 80mph

I'm from Texas. Our posted limits are 85. We go at least 90 either way. still under 4k RPMs.

your car isn't going to explode because you drive at 4k RPMs for an hour for a commute.

Well.. I'm in need of new tires so the Invos are in order and sound deadening as well. These things help and are not that expensive.


The coilovers are the most expensive. If I can find a rear diff and swap it for a lower ratio for say less than 500$ It'll pay for itself, lower the rpms and also I can go FI after the contract is done and have better traction.


Thanks for the constructive suggestions.

You will not be disappointed with the invos as far as daily drive-ability goes. If you were local I would sell you my set cheap cuz I am going with race tires this year lol. I wouldnt do the diff man. Invest in a oil cooler so you can drive harder and not worry about your engine. Heat is what kills engines not RPM's however RPM's do = heat. The stock rad is fine but the lack of an oil cooler is what should concern you.

Don't even worry about it. For the first year I had the car I was commuting 55 miles each way in/out of NYC. Speeds were between stopped and 90mph depending on traffic with good to terrible pavement quality. The noise is certainly bearable but if you're already planning on mitigating it, great. Don't be concerned with engine revs just change the oil around 6k miles and the engine will be fine then do tranny and diff once a year. If you go with quieter tires you will likely notice them wearing more quickly but not enough to be a problem other than the cost.

Actually I didn't think of the oil cooler. That is a MUCH better way to help with wear due to heat.


I totally understand that the car CAN be driven at such high rpms for extended periods of time but wear is higher with higher RPM and that's a FACT. Also the reason the auto gets such a great mpg while cruising at higher speeds is because of the rpm it cruises at (gearing).


I think invo's and oil cooler it is for now.

Dynamat: If you DIY, it will only be a couple hundred. If it is installed, you are probably well over $500 for labor since it is a full interior breakdown.

Final Drive: $1500-1800 depending on what brand and who installs.

Decent Rims: $1000+ (plus TPMS)

Tires: $500-600

You can buy a second car for that easily.

Don't want a second car man... extra insurance, extra maintenance


Final drive 1.5k ? wtf I can buy a used pumpkin out of an IS and swap it in my garage for less than 500$


I think the rims I can keep using just change tires.


So I'm looking at the least 500$ in tires, 500$ Diff, sound deadening ~ 200$, Oil Cooler 350$


All for less than 2k and I can keep the car and maybe Boost it after my contract ends :D

Honestly run good oil and change it often you will have next to no wear metals. Here is a UOA from my car. You can see that I have next to no wear metals at each interval. I drive around 3k-4k rpms myself when I am commuting but I do also have an oil cooler. I do drive the piss out of my car though. I hit red line a few times a day.

Attachment 132865

My commute when I git the car was 55miles each way and is now 27 miles each way. I am prepping for STX but have toyed with just slapping on a SC and going for comfort. As it it is fine though (granted I have an AT so RPMs arent a problem to begin with)

Option #1: Buy a DD

Option #2: buy a DD

If you really dont want to realize you bought the wrong car and are willing to spend money instead of taking the hit trading in/selling

1. 17s will ride much better then 18s. Hell the stock rims are fine really even just slap a 225/45 on for a bit more sidewall even

2. ST coils or Bilstein shocks with RCE or Swift springs

3. sound deading will really quiet it down since the car basically has none. It will add weight but that doesnt sound like a concern.

Do those before swapping the final drive and really killing the car.

Oh I forgot to mention you need 225/45R/27 Invos as thats the smallest size they come in. They fit fine on stock rims.

@migueralliart

1. Delete the sound tube / growler tube pumping induction noise into the cabin. This is free to do, and removes a good 3-5 dB from the cabin.

2. Make sure your exhaust setup doesn't drone between 2700 - 4000 RPM. If it does, you may be in need of a resonator added or a just getting a quieter exhaust geared towards low noise.

3. Sound deaden the cabin (not the trunk). Most of the rest of the uncomfortable sound coming into the cabin comes through the floor, back seat, and rear deck lid (where the 3rd brake light is). Use a 3 material method (MLV+CLD+CCF). There are tons of threads on this, use the search tool.

4. If you want to upgrade coils for road comfort cheaply. Get ST Coilovers ($800). Decent quality, and softer springs make highway cruising nice. If you want to spend more for better damping and improved performance, I am partial to RS-R Sports-i ($1700). If you want to spend even more, Ohlins Road & Track @ $2700 are top notch for a daily driven car.

5. Upgrade your amplifier and speakers to go with your new head unit. The improved sound will go a long way to making the ride much more enjoyable and tolerable.

I wouldn't touch the final drive. You won't lower the RPMs in top gear enough to make a difference and 6th gear will be even less useful. Keep your 17s with 45 series tires in a lower performance category. Going to 18s will only make your sidewalls narrower as others noted. This hurts ride comfort.

You might consider under panels for the aero (better gas mileage) and reducing some of the reflected road noise, also in the DIY section there is a thread on a complete sound deading for a BRZ that should cover everything you need to know. It's what I followed to do mine.

If you don't have a sub, and have no plans to add one, do as @DAEMANO says and do the standard CLD/CCF/MLV treatment on the rear seat back / deck lid to block the trunk out.

I just recently completed a giant project to quiet my car down while also adding an OEM Audio+ Reference 450Q setup. I did things slightly differently due to the sub, but man - can't say enough about how much quieter it is in the car. My exhaust is nearly silent and sound from the back of the car is basically nill.

I bought a bunch of 3M Thinsulate TC3303 and lined the roof, stuffed it in the kick pillars and the frame rails, lined the inner door panels, the outer rear quarter voids and the trunk lid (covered by BRZ trunk lid trim) with it. CLD wherever there was resonance, but not excessively (used the equiv of 1.2 bulk packs of dynamat for the whole car). CCF and MLV on the inner door skins, the kick panel areas, floor, rear wheel arches, and a simple cut piece laid under the trunk mat. The back of my car is almost silent now, I can still hear some noise from the front wheel wells.

I have some hydrophobic melamine foam on the way to me from Don@SDS to try putting in the front fender cavities as an experiment to see if it'll reduce the front tire noise. We discussed it and he thinks it "might" work.

I didn't completely cover everything that I could have in MLV. I didn't have time to do under the back seat, but I'm not sure that I care. When I turn my head side to side, I can't really hear any noise coming from the back of the car.

I took a ton of pictures but haven't gotten them off my camera yet.

Meh
I drive 4 hours a day twice a week and 2 hours a day the rest. TRD exhaust and RSR Super Downs. You get used to it.
Now things seem wrong if I am driving a car that is quiet and smooth.

Aint that the truth. every time I drive another car I am like wow this is quite lol

I put Pandora on and turn the radio up. Seems pretty simple? Cruising at 80, I have never liked the RPM's since owning subarus, but they've all cruised in the 3K plus range.

Quite what? Quite quiet?

$200 will not get you any amount of sound deadening that is worth your time or effort. Plan on 500-600 at least. Just adding "dynamat" or CLD tiles in general is a complete waste of time. I've made that mistake a couple times in the last 18 years of modding cars. Don't do it. You need to go all out, or don't bother.

Beyond what others have said, I would pump the tires up to 40psi cold and get an alignment with road crown in mind. You might want front crash bolts for that. Don't ruin the car with a longer final drive or crap coilovers. I would also buy ventilated leather seats with cooling to cut the sweating.

By this point we all know my English is on par with a 4th grader :sigh:

Just giving you grief. :cheers:

hahaha you and everyone else :cheers:

Ok so it seems the list goes like this:


Tires
Oil Cooler kit
Tweaked Sound System


500G of hot yoga videos saved on my radios SD card

:cheers:


I would also delete the sound tube as well. Its free to do, the plug for the cigarette lighter in the glove box works perfect lol

Plus the engine looks better without all the sound tube stuff on it.

I'd suggest putting on 16's with a nice tall sidewall(45~50) and adjusting your seat properly. It's can be a very comfortable car👍🏽

Wait, the radio plays videos?

I'm running TRD and UEL on my FRS but I drive an all electric vehicle as my daily. Each car is on the complete opposite end of the dB spectrum. I know this feeling lol.

I was just going to recommend these to OP, the JDM underpanels. "Subaru documentation indicates that these panels lower the coefficient of drag by a small but measurable amount."

An oil cooler is only necessary for a track car. Running steady at 85+ is not even close to a problem for the stock cooling system, AFAIK.

Mine does :iono:

edit: Hell I got internet and access to google on my headunit while I drive. My buddy looked up porn while I was driving once, true story.

I think OP should measure temps to see for sure. I know I need one for the way I drive my car.