To boost/improve Yaris, or move on....?

[Jason@SportsCar]

Originally Posted by OTB

I appreciate the input. I'll have a look at 4.xx final drive and lsd units. The flywheel feels so light on the stock yaris (heel-toes are just a tiny blip), I hadn't even considered there's lighter ones out there. Since the Yaris makes no torque out of the hole, does the lighter flywheel make streetability really suck (like starting up a hill, etc.)?

Wheels-I'll explore the options. 13" would be cool, especially with a smaller overall diameter tire, but for street class time attack, I'm not sure I'll find 13" compatible tires (RE-11, RT-615, Kumho XS, Star Spec, etc.) Race tires seem to be more available in funky sizes.

Again, thanks guys, I certainly studied up on Garm's posts, Jason's article in SportsCar, and Focus's install thread.

I'll try to have a good look at Jason's car at Miller and take some notes.

Without FI power you really need gear multiplication to make the car move, it is a world of difference.

The stock setup (flywheel/clutch/pressure plate) is 26lbs, our lightened setup is 18lbs. While it is a significant difference, it is totally street-able. The problem with most race setups on the street is to aggressive of a pressure plate/clutch combo, some of them are an on/off switch. We used a 3-puck solid hub clutch (weighs 1lb), but a very mild pressure plate - its not like we are trying to hold back 300hp - so it is easy to drive. The flywheel alone wont have much impact on how the car drives, it just lets it rev more freely.

If you are going to run a street tire class the 13"s wont work, there are no options for competitive street tires (140+ tread wear) in those sizes. I would go with a 15x8" wheel, and a 225 Hankook RS3.

I don't think we are going to make Miller this year, its not in the budget.

[why?]

Originally Posted by Jason@SportsCar

The stock setup (flywheel/clutch/pressure plate) is 26lbs, our lightened setup is 18lbs. While it is a significant difference, it is totally street-able. The problem with most race setups on the street is to aggressive of a pressure plate/clutch combo, some of them are an on/off switch. We used a 3-puck solid hub clutch (weighs 1lb), but a very mild pressure plate - its not like we are trying to hold back 300hp - so it is easy to drive. The flywheel alone wont have much impact on how the car drives, it just lets it rev more freely.

1 pound! Do I even want to know how rare and expensive it is before I get my hopes up? Is it something that can last on a daily driver?

[Jason@SportsCar]

Originally Posted by why?

1 pound! Do I even want to know how rare and expensive it is before I get my hopes up? Is it something that can last on a daily driver?

Nothing exotic at all, its right off the shelf from SPEC. The stock clutch disc is only 2lbs, and it is a full disc with a sprung hub.

I can't think of any reason it would not work for a daily driver. The solid hub is not as smooth as a sprung one, but you really only feel it in 1st gear.

[cali yaris]

for street class time attack, I'm not sure I'll find 13" compatible tires

I run 13x8's with Hoosier 225 R6 tires for road courses, but I think that would put me out of "street class".

[cali yaris]

The flywheel feels so light on the stock yaris (heel-toes are just a tiny blip), I hadn't even considered there's lighter ones out there.

Stock is about 15 pounds, the ones I sell are 9.4. and 8.6. Big difference.

[ilikerice]

I am not sure about NASA rules but i do know if you plan to autocross with SCCA and you wanna stay in Street Touring class. Dont boost. Stick to what Garm and Jason are saying..

BUT if you do boost, I think the supercharger is your best bet for the instant boost and also you are looking for only 140-150hp range. perfect setup. Then that will put you in Street Modified class. Then you can get those Rcomp tires on 13" wheels and be more competitive..

We have a guy in our region who runs a Cooper S and KILLS everyone. He is Stuart K. Scroll down to the RAW TIMES. He is running in D Stock class.. Its in the driver. This particular event he let someone else run his car also "phillip lee". that kid is a prodigy.
http://buccaneerregion.com/ce-7-11.html

some of my insight and bit of input

I like this thread, giving me some insight on future plans for the yaris. thanks!

[cali yaris]

We used a 3-puck solid hub clutch (weighs 1lb), but a very mild pressure plate - its not like we are trying to hold back 300hp - so it is easy to drive.

That's a great set up. My Stage 4 clutch is a little twitchy for the street.

[Jason@SportsCar]

Originally Posted by cali yaris

That's a great set up. My Stage 4 clutch is a little twitchy for the street.

Well you do have about twice as much power as us.

[cali yaris]

^ yeah and half the skill.

[mazilla]

Great thread.

[TRD.RiC]

Brakes are a must thats for sure. If i can put my input into this id say get braces as a 1st suspension mod. IMO is prolly the best mods done that ive done yet. without them i felt that the body was working too much. i got the 3 underbody brace from UltraRacing and it really feels good now. Just going over a speed bump you feel that the body of the car doesnt wobble as much. The car feels a lot stiffer and when i push it I like the feel that Im into a solid car. I got coilovers and RSB as well but my 1st mod was the braces and I can defenitly say that i got better benefit from those mods that the shitty tein basic coilovers i got

I starting doing some laps in the car fully stock except for advan a032r tires. In a way I am building the car to what my track sessions tells me can be improved. So my setup was the braces ---- RSB ---- Coilover(which I really really really dislike) and alignment at same time. The car is tail happy with me driving but I am really rough on it when doing my inputs. I have to improve that a lot (my racing instructors loves to ride with me but say ill kill the direction of the car really fast.) The front bushing where torn at 33000km?.

Anyway. Go out there do some laps and build it from there is what I would say more than try this try that. We all drive differently and you build it for your driving habits not some other person. It's ur money!

[ilikerice]

I like braces. But I think if you wanna track a car the first thing you should invest in is a roll cage an fire extinguishing system. But I am a little confused what the OP goals are for.
Just simple PDX track events are great and fun and you dont need all the safty equipment.
Then you mentioned autocross which those braces will put you in SM class.
IF you run track events and build it to a specific class there. You may end up in a non competitive class in autocross. Most of the guys who run track events use autocross to dial in thier cars a bit more and just fill in the gap between track events. They usually run Prepared class's.

Depends what type of racing you wanna do to be competitive in.

[cali yaris]

I think if you wanna track a car the first thing you should invest in is a roll cage an fire extinguishing system.

I tracked my car a month after I bought it on stock tires and Tanabe springs. I didn't put a cage in until two months ago. So I will respectfully disagree; you can go have a lot of fun before installing all that stuff.

[cali yaris]

+1, the final drive + the output shaft.

[fnkngrv]

This is an awesome thread and giving me much more useful info than I knew about this car. It could greatly shift my plans. Great way for the OP to start things.

[CrankyOldMan]

So after poking around for part numbers with the xB transmission, it looks like in '07 they went with the E351 instead of the C50 (due to engine change). This would mean that only an '06 or older xB/xA tranny would have the desired output shaft and gear ring? (I looked into the part numbers and they match for xA/xB).

How can it be the same transmission (C50) if it has different gear ratios inside? Seems like that would warrant a sub-designation or something to make it apparent, especially if I were to go to a junk yard and try to find one.

[cali yaris]

Jason posted the xB part numbers needed:

If anyone is interested in the parts needed to do the xB final drive (4.312) swap:

33321-52110, output shaft
41221-52270, ring gear
90105-11040, ring gear bolts (8)

[CrankyOldMan]

Originally Posted by cali yaris

Jason posted the xB part numbers needed:

Is there a difference between the old/new parts? Some sites don't have the new numbers, so here's the old ones:

33321-17011, output shaft
51221-12340, ring gear
90105-11040, ring gear bolts (8) (no change)

At this point, I'm going to either make a new thread or keep chasing these ideas on the xB final drive swap thread