Making the car faster with out hp gains?

[Pro]

nah no power gains - just reducing the weight the engine has to turn. it will feel faster - and be faster too - but not increase engine power in the slightest.

basically if you have to take the auto off for shiftkitting / new TC or whatever - fit the flywheel then. don't pull the whole lot apart JUST for the flywheel.

i didn;t have to ride the clutch at all -i don;t see why you would have to either.

 

[Damien]

Just from my experience with motocycles in traffic... because the flywheel is pretty much nonexistance there's not much rotational inertia to keep the engine ticking over at idling revs when you put some load on it.

At the moment I can crawl in traffic in 3rd gear doing 25km/h with my foot off the throttle them smoothly pull away so i was wondering if the flywheel's mass would be helping with that. I have to get a new clutch fitted in a few months and a lightened flywheel is an idea I'm toying with so if you didn't have any dramas I'll look into it.

 

[Pro]

no dramas at all.

 

[stevechumo]

the seats are not light, the passenger side is 85 lbs, the drivers side is every bit of 120 lbs. I know lol I sold the passenger side on ebay, and got ate up buy shipping, and the drivers side weighs a ton more. I know if you got some sparco seats in the car you'ld feel a difference, but then again you'd be loosing the lexus appeal. But sparcos are classy too.

I haven't taken out the front seats so I don't know. But the rear seats are very light. I think it's less than 5 lbs. I took it out to install the rear speakers. Reducing weight is not my concern. I'd like to keep a nice luxury Lexus look and feel. I would install a forced induction system instead.

 

[stevechumo]

it probably would be worth the money - but not if you have to pay someone to reef out your engine and trans *JUST* to fit it.

generally, lightweight billet flywheels are about 100% stronger than stock cast-but-hardened flywheels. the one i had in my RX7 weighed 4.4kgs and looked like a round piece of swiss cheese - revs would rise and fall like a motorbike.

I've been thinking about ligher & stronger flywheel for my SC400. However, I don't know where to get it. And it should come at the same time with the torque converter upgrade to save time and $$$.

 

[Peewee]

Jibby, before you get too excited about buying a lighter flywheel you have an auto. Auto's don't have flywheels. Only manuals do.

Also regarding diffs, most 1UZ cars already have a 3.7 or 3.9 from factroy, so to get something else you'd be looking at a 4.1 or 4.3

On the flip side of this the 1UZ falls flat on its face above 6000rpm, and really tapers off above 5500rpm.
Going to a 4.3 diff will keep it in this range where you will have very little power/torque.

I've gone for a 3.73 in mine, to try and keep it in the powerband longer.

 

[Pro]

sorry i presumed the soarer was more like a 3.1 or 3.5 at most.

Auto's don't have flywheels. Only manuals do.

manuals have flywheels, autos have flexplates. basically all it's for, is for the starter motor to spin a ring gear.

i have seen lightweight flexplates though - but i assumed yours was a manual there, jibby. i prob should read things a little more throughly.

 

[Damien]

It also depends on the gearbox ratios. The 2nd & 3rd gears in the W58 (which I have) are taller than the R154 so the 3.916 just felt too tall. When I fitted the 4.083 it felt much more responsive. Even though the engine hits a wall at 6000rpm I can get there quicker with the shorter diff. However, in a lighter car than a fat V8 Soarer the 3.916 would probably be better for the reasons you say Peewee.

 

[Peewee]

i'm sorry...? how does the starter motor turn the ring gear then?

Flexplate.
A very thin bit of metal that has 2 purposes.
1) it holds the ring gear
2) it holds the torque converter

Must weigh <1kg tops.

 

[Peewee]

Looks like this

 

[Pro]

it's okay dude - i realised what it was called and edited my post. was hoping no-one saw!!!

but 1kg? really? i've seen swiss cheese versions that must weigh less than 300g then!!!

 

[Peewee]

Hehe, gotta love brain farts.

I wouldn't be surprised if it weighed up to 1kg.
Sure it feels light, but its large.
The larger something is, the lighter it feels. Never actually weighed one though.

But that the end of the day, the <1kg worth of flexplate is nothing compared to the 20-30kg worth of torque convertor and fluid.

 

[Pro]

yeah i've seen even less of a flex plate - like holes everywhere around the outside ring there.

 

[jibby]

Well you learn something new about these cars everyday.....The old Chevy's and Fords all have the heavy fly's so I assumed these IUZ's would be the same. Yes the wheel that spins when the starter motor is engaged that every auto tranny has....that is what I was thinking..

Peewee - I never get too excited about mods, only the results after the mods. Thanks for the clarification on the fly.....

240- What's up mate? Are you slipping? :liar: I am only kidding, don't take that seriously, please. You were only trying to help and I thank you anyhow. I wish your assumption was correct that my car was a manual with the V160 Supra conversion in it.:veryhappy See ya-

 

[lowboost]

I haven't taken out the front seats so I don't know. But the rear seats are very light. I think it's less than 5 lbs. I took it out to install the rear speakers. Reducing weight is not my concern. I'd like to keep a nice luxury Lexus look and feel. I would install a forced induction system instead.

I hate to sound like a jerk, but read the title of this post. With OUT hp gains....

Yeah I've held my starter plate from my 1uz and its got holes all in it to reduce the weight of the rotating mass, its about as light as its worth the time trying to modify it. I know the torque converter weighs every bit of 45 lbs. About the only thing I see worth changing is the hood, and seats, if you want to retain the luxuary appeal.

jeff

 

[Damien]

That's true, if you strip it out bare it's hardly a luxury car anymore. However, if you're going to the track there's a heap of weight that can be saved just for the day.

 

[jibby]

The only other way I can think of that would make the car faster without producing more power gains would be altering the aerodynamic's of a car. That really doesn't apply to a street sportscar as they are already made from factory to be aerodynamically designed to a certain degree, and any improvements made would not be noticeable in my opinion for street use... So this is what we have come up with so far:

1) Weight reduction (stripping the car of it's weight).

2)Reducing weight on the engines flyweel, rims, driveshafts, etc.. this allows the engine to turnover with less effort creating more torque/power at the wheels.
3) Gearing ratio's in the differential and tranny (drivetrain)
4) Reduced wheel diameter sizes in the rears.
5) Now lastly the aerodyamic's of the car (creating the least amount of wind resistance)

 

[Pro]

pretty much spot on there jibby...

 

[lowboost]

I did all those! MR2, very aerodynamic, less weight (nearly 2400lbs), short ratio gear box (same weight), light weight flywheel and spec clutch (both lighter than that torque converter), light weight headers no cast iron and mild steal.... keep watch hehehe

 

[jibby]

Lowboost did you do the aluminum driveshaft as well? It sounds lto me like that little MR2 of yours is going to fly....