Confirm understanding of lightweight mods

[nikitopo]

Originally Posted by churchx

nikitopo: how many twins are tracked? I wouldn't bet even on every tenth. Probably one in 50 or 100. How much time/mileage is spend during daily drive during traffic with all it's caveats/specifics from those that are tracked? Everything is compromise. And what might be acceptable in very low number very limited series won't work for most, thus i'd be very careful with choices done at such or even more so, at race spec cars, where creators simply didn't care about daily driving at all.

Noone said it is a must mod. Depends the case and for sure I would never do it in my daily driver which is a different car. Good thing is that we have a choice. Some will love it and some will hate it. Even the additional noise in certain RPMs might be unbereable for many. Independently of a tracking car or not, there are some people that are missing nowadays the "raw" result and looking for it. It is not a coincidence that other manufacters are offering "R" type versions in their model range with less sound deadening material, noisier exhausts, single lightweight flywheels instead of dual mass flywheels, A/C delete options and so on.

[churchx]

nikitopo: that was for more then probable reasoning, "why toyobaru didn't do that in first place?!!". Everything is compromise and chosen according specific application / target niche. Also for every Type R civic (which probably ar much more numerous then eg. 14R60) much more plain civics are sold. For every GT3 porsche, much more "normal" 911. And in my eyes THE distintinctive feature of twins is cheap price. Making of "R" version also needs budget that needs to be reearned back somehow, but now without help of large volumes/numbers scale. You probably would be looking at caiman then at track spec twin of caiman price.

[nikitopo]

Yes I agree. Even the 14r60 was in the price range of a cayman. However, it looks that some people don't look only on the price advantage of the base toyobaru. Other factors might be to have something different that does not exist in volumes (Nurburgring is full of Porsche's), to have the better reliability of a Japanese manufacturer, to have a super-car territory chassis regarding stiffness and so on.

[churchx]

And that's why also all mods we do to our twins have to be looked through prisms of what we prioritize most, what we wish to change, how much we are willing to pay, what(if) we are willing to sacrifice. For everybody all of that is different, and if it's just generic start of info inquiry for OP as it seemed to me, i feel always obliged to mention also downsides of changes/"upgrades" & to advise rethink/choose/decide what and if one really wants. It's always pitiful when one pays large amount of money on mods without much nfo then subjective gut feel and nfo from some niche internet groups and gets something opposite to what Really actually wanted and maybe also spends even more money to fix/workaround some of changes.

[SuperTom]

Im down to 2500lbs with still an ungutted interior. Major compromise I had to give up was AC delete for only 15lbs so I may consider putting that back in.


I did chunks at a time to feel the difference.
I did lighter wheels/tire along with lighter pulley
I did Lightweight Wilwood front brakes (-30lbs) and CF driveshaft
I did lightweight battery with rear seat delete
I removed front and rear bumper beam and same time
I did empty windshield reservoir & AC delete with spare tire/jack removal


The method was to keep the front & rear loss close each time to maintain the stock balance built into car.
Each time I noticed a drastic improvement in acceleration.


The OP's question will reducing reciprocating mass improve HP? No. But the car will get to the same HP #'s up high quicker is how I see it.

[why?]

I love how people that never would even think of doing certain mods love to say how they affect things.

I bought the lightest flywheel on the market and have zero issues in stop and go traffic, no idea why anyone could have issues unless they've never driven a manual car before. Also have a cf driveshaft. It is all about responsiveness. It of course is not eye opening world changing, but you can feel the difference from stock.

And saying you aren't going to get a gas mileage change is one of the absolute dumbest things I have ever seen written anywhere on any topic. In my Yaris I went from stock to lightweight pulleys, an intake, and some of the lightest wheels you can possibly buy and there was an absolutely massive difference. Of course that is a 2200 lb car with a 100 hp engine. Taking 200 pounds out and drastically lowing wheel weight made a huge difference.

Now if you floor the car everywhere and act like speed racer, then of course you are not going to see an increase in gas mileage.

The most important thing is to decide what you want to do with your car, and then ignore the noise. Lots of people have opinions on everything, and far too many love to express it even though they'll never even think of seeing if theirs is anywhere near right or wrong.

[86TOYO2k17]

With any mod I would try to find as much before and after testing under the most strict conditions. Sometimes I search other car forums like s2000/mustangs or whatever to gather more testing data. If rotational mass made a difference it should be relatively the same percent across most platforms based on percent of reduction vs weight/power etc...

As well as reading up on and looking at the physics of what is actually taking place. Every gain/performance increase should be able to quantify with mathematical data.

Many ppl who do a mod will usually say something like “it was worth it or I felt a difference” to justify and feel better about spending x amount of $ on something. With supplying little to no actually data or testing results.

[SuperTom]

Originally Posted by why?

I love how people that never would even think of doing certain mods love to say how they affect things.

I bought the lightest flywheel on the market and have zero issues in stop and go traffic, no idea why anyone could have issues unless they've never driven a manual car before. Also have a cf driveshaft. It is all about responsiveness. It of course is not eye opening world changing, but you can feel the difference from stock.

And saying you aren't going to get a gas mileage change is one of the absolute dumbest things I have ever seen written anywhere on any topic. In my Yaris I went from stock to lightweight pulleys, an intake, and some of the lightest wheels you can possibly buy and there was an absolutely massive difference. Of course that is a 2200 lb car with a 100 hp engine. Taking 200 pounds out and drastically lowing wheel weight made a huge difference.

Now if you floor the car everywhere and act like speed racer, then of course you are not going to see an increase in gas mileage.

The most important thing is to decide what you want to do with your car, and then ignore the noise. Lots of people have opinions on everything, and far too many love to express it even though they'll never even think of seeing if theirs is anywhere near right or wrong.

Oh yeah almost forgot about the MPG increases as well with weight reduction. This on about 40% City, 40% longer roads, 20% highway.
Gruppe-S UEL and OFT Stage 2 v4.03
31.5 not bad

[Ernest72]

Originally Posted by SuperTom

Im down to 2500lbs with still an ungutted interior. Major compromise I had to give up was AC delete for only 15lbs so I may consider putting that back in.


I did chunks at a time to feel the difference.
I did lighter wheels/tire along with lighter pulley
I did Lightweight Wilwood front brakes (-30lbs) and CF driveshaft
I did lightweight battery with rear seat delete
I removed front and rear bumper beam and same time
I did empty windshield reservoir & AC delete with spare tire/jack removal


The method was to keep the front & rear loss close each time to maintain the stock balance built into car.
Each time I noticed a drastic improvement in acceleration.


The OP's question will reducing reciprocating mass improve HP? No. But the car will get to the same HP #'s up high quicker is how I see it.

Is this a track only car. no bumper beams could be nasty in a crash.

[SuperTom]

Originally Posted by Ernest72

Is this a track only car. no bumper beams could be nasty in a crash.

No its street ever hear of a motorcycle. Obviously its use at your own risk. I hear the Japan version of these cars does not use these beams its a US thing.
Beams aren't designed to help in a high speed wreck so if you hit a tree going 100 you are FK'ed either way. Its mainly so insurance companies don't have to pay for radiators ect that will get damaged in low speed collisions.


Line 2 from the NHTSA:
The car bumper is designed to prevent or reduce physical damage to the front and rear ends of passenger motor vehicles in low-speed collisions. Automobile bumpers are not typically designed to be structural components that would significantly contribute to vehicle crashworthiness or occupant protection during front or rear collisions. It is not a safety feature intended to prevent or mitigate injury severity to occupants in the passenger cars. Bumpers are designed to protect the hood, trunk, grille, fuel, exhaust and cooling system as well as safety related equipment such as parking lights, headlamps and taillights in low speed collisions.


https://one.nhtsa.gov/cars/problems/...per/index.html

[guybo]

Often times people mistake rotational Mass with reciprocating mass. Rotational Mass makes much less difference (the spinny bits) than reciprocating mass does (the uppy Downy bits)

[mrg666]

Originally Posted by guybo

Often times people mistake rotational Mass with reciprocating mass. Rotational Mass makes much less difference (the spinny bits) than reciprocating mass does (the uppy Downy bits)

And it is not all about weight. There is vibration to consider as well. Reciprocating and rotating masses contribute to vibration differently. That is why race engines require a certain mass on the crank pulley. Because, while lighter crank pulleys improve throttle response, they cause vibrational power loss at high rpm. This has been discussed so many times but anyway. If I change my crank pulley, it will be Fluidamper which is not light but designed for damping of vibration at higher revs.

[Jasonb]

Originally Posted by SuperTom

Oh yeah almost forgot about the MPG increases as well with weight reduction. This on about 40% City, 40% longer roads, 20% highway.
Gruppe-S UEL and OFT Stage 2 v4.03
31.5 not bad

On my 2017 with 13,000 miles I have averaged 31.6mpg since the day I got it. Only mods are catless JDL UEL header, Nameless muffled track pipe, and the V4 OFT tune. So I shaved a few pounds with the header and very minimal axleback.

[SuperTom]

Originally Posted by Jasonb

On my 2017 with 13,000 miles I have averaged 31.6mpg since the day I got it. Only mods are catless JDL UEL header, Nameless muffled track pipe, and the V4 OFT tune. So I shaved a few pounds with the header and very minimal axleback.

Yeah with MPGs there are other factors mainly how much you put your foot into the gas pedal. I should have mentioned I was around 29mpg with exhaust/tune mods. I went up to 31.5 with some fat loss