MPG vs Performance (Yaris)
 

Been a while since I posted and so just wanted to get some people talking.

I bought a yaris a little over a year ago. I have been trying to decide what direction to go with the car and have been doing some small performancy things to it.

My original idea was that it was going to be my daily driver after my Cavalier dies but I have actually made other arrangements there.

I have done the following things to it:

-stiffer springs (~1" drop)
-rear sway bar
-Short Ram Intake (SRI)
-heat wrapped Tri-Y header (stainless steel)
-shift extender (3" extension)
-short shifter
-OEM armrest
-OEM rear bumper protector
-tachometer
-ultragauge
-OEM cruise added

I just ordered a mandrel bent 2" exhaust from the resonator back. that should be here in about a week or so.

I am seriously considering a supercharger that is relatively popular in the yaris community.

I have heard that the S/C actually doesn't hurt mileage when it is off. The S/C kit actually has a clutch pulley so you can have it on or off. That was kinda neat.

The stock hp of these cars with a manual is 90whp (106hp as per manufacturer). I have heard that with the supercharger you can achieve 120-135whp depending on what other stuff you have on the car.

I am just curious of any thoughts that anyone has about all this. I know this isn't a typical discussion for this board but hey, I'm trying to liven up the place.

-beef

That's interesting to learn that the S/C can be disabled. That's a great way to switch from a fuel efficient ride to something quite a bit more peppy. Have you ever ridden in a Yaris that had one installed?

I have not but have heard good things about them. The power is reliably there and the boost level is well within the limitations of the stock internals.

I have heard that the pulley is situated like an A/C clutch pulley and can be cut on and off. It has a selector switch for low/medium/high which is actuall throttle position. low basically means any throttle and it's on. high is only at WOT. there is actually an off position as well.

the S/C is expensive so it is more of an idea I have been throwing around for a while. I think even with the upgrades I have done so far and several WOT runs I have made, I am still in the 40mpg region.

Interesting, If you manage it correctly you should be able to maintain the same FE while improving power.

I've had fun with my car; improve power a little, then make sure it doesn't hurt FE, then do a mod or two to improve FE. It's a never ending cycle that pushes the envelope in both directions.

Out of curiosity, how much does the super charger run?

They have come down a bit. It was originally right at $4000 but is now around $3400. That is for the entire kit and includes management (piggy back fuel controller). It is completely plug and play.

There are turbo kits out there but they aren't complete and you have to tune them yourself. There are too many stories of guys blowing motors because of running lean.

I know it is a lot but it is not that popular of a car to supercharge so the price is high. if it were a honda civic or a mustang, the price would probably be less than half.

Forced induction did me well. My passat got me around 32mpg mixed driving while able to have some decent power and response. Supercharging most likely will never recoup the savings in gas mileage though if you tried to save some gas with it. Tuning is what matters the most.

I would never spend 3-4k on mods that give you a 20-30whp difference either.

If you get 145 whp that's a 50% increase - wow that thing will really move! I wonder what the price is for the eCycle electric driven SC ? Would give you boost without engine loading off a 12 volt battery.

kracka,

I had issue with the HP gains as well but if you look at it from a percentage standpoint, it's pretty significant. The price point is what has been keeping me from ordering it. I have been contemplating it for about a year now. There are other options (turbo) that make more power but there is not a known plug and play tune for it. every car is different and a lot of guys go lean and pop motors. I was actually told that a good dyno tuning session (note: tuning session) usually runs around $700.

Jangeo,

there are a few boosted guys (turbo guys) that are making killer power. the biggest drawback is that there is a hard threshold around 200whp where you have to change internals because the connecting rods can't handle it.

One guy has a Scion xA (same drivetrain) that is running under a 12 second qtr. I think his time was 11.95 or so. he is running something like 28psi though. He has more money in his engine than I even want to think about. most turbo kits for these cars run 8psi (as does the supercharger).

That's about half an atmosphere so it sounds about right that you almost get 50% increase. Turbos put more strain on the exhaust and heat the oil more to keep things cool and you can't turn them off easily. That's why the supercharger is a cleaner power booster. Need to do some math on the cfm needed to get the boost at high rpm but you should get plenty at low end. Looks like about 174cfm at 6500rpm for the 1.5 liter engine NA so it is not big enough unless you get a 24 volt battery to power it and you will get a little drop in boost near redline.

Low Voltage Electric Supercharger | eCycle, Inc.

The scary part is that it looks very similar to the supercharger I am talking about. Honestly can't bring myself to pull the trigger on it as it is nice to have money in the bank.

BLITZ supercharger kit - Yaris - Micro Image - parts and networking for small cars

you can see the 6 bolts that bolt on the intake side of it. instead of the pully the S/C has, yours has a motor.

Yeah money in the bank is a good thing ... although now gold is a better investment . . . Banks are NOT paying enough interest on savings these days, its criminal and leave it there for a year without activity then they hit you with a $5.00 a month fee!

Looks like that kit includes an intake manifold too, gotta hold that beast up with something besides a plastic intake!

the plastic intake kinda sucks. something they are addressing. There are a few different intake manifolds that different people are working on. most do nothing for topend but fatten the bottom end of the hp curve around the 2.5-5k rpm range. actually a good place to add power.

I have been going the bolt-on route and thus have seen very little gains but they are all cumulative. with intake, header, exhaust, and light crank pulley people are dynoing around 105 (from a baseline of 90) that is actually a pretty big increase given the baseline. I am just thinking of adding more. just having a hard time coming off of that much money for anything. also, I can get a nice older miata for around $4-5k.

my company offers an ESPP (employee stock purchase plan) that I take advantage of. you can put in between 1 and 10 percent of your salary and they do 6 month intervals. at the end of the 6 months, you get the lower price of either the beginning or the end of the 6 months and in addition to that, you get 15% off that. an instant 30% increase. I actually just started with it so I cash out in february. I intend to cash out immediately. I also have a money market that I dump money in. does better than a savings but still not hitting on much nowadays. to an actual investor, my portfolio sucks but the fact that I actually have one says a little about my finances.

Jetta TDI for 5k would be a better investment, but that is just me!

Beef have you checked in with ScionLife.com about a used supercharger kit? One of the nice things about that engine and fuel injection system is that it uses a flow sensor and not a map sensor so you can push more air through the engine at lower speeds to build up low and torque and the fuel system should be able to handle it without any adjustment to a point. I had read of a compressed air supercharger that used air from an air tank sprayed with a nozzle into the intake to boost the air pressure a little. Pretty good for a short burst of speed and cheap. You recharge the tank with a little 12 volt compressor.

the miata was just an example but yea, you can buy a car for that amount or a little bit more.

the blitz kits go on sale from time to time and the ones for the xA and xB are the same I think. one of the guys on yarisworld got a killer deal for one at $1600 and I am kicking myself for not getting it but there again, it was used and I wasn't ready to pull the trigger on that kind of investment. they don't come up used very often.

I think you can get away with around 3psi without any type of extra fuel management. a few people have experimented with low boost turbos. they don't make that much power but there is no tuning to worry about.

Very cool project I like it. I'm a turbo fan myself but I like the idea of a clutch supercharger that comes on only with throttle - very good idea. Not sure if that would work on a big V8 due to the torque on the clutch, but for a small engine - perfect. Definitely go for the freest smoothest flowing exhaust all the way back then see what can be done to over-write/retune the ECU map as that is where you will get good gains from lean burn at cruise.

My 550hp turbo LS1 in a heavy auto sedan has got 9.9L/100km on very poor quality injectors so we are about to swap in EV14 state of art ones and hope to pick up quite a bit er economy.

actually took care of the exhaust this weekend. after the resonator, it shrinks from 2" down to 1.75 so that was more my focus. I also used a straight through fiberglass filled muffler (not really a glass pack).

Instead of reposting all the pics here, I'll just put a link. I am an active member on yarisworld.

Custom Mandrel bent exhaust - Toyota Yaris Forums - Ultimate Yaris Enthusiast Site

my goal was more of a stealthy look. I am going for sleeper but usually with that you need power...lol

What is the non-glasspack straight through fiberglass filled muffler?

sorry, I meant more the packaging. it looks like a regular muffler but I guess it is a glass pack. It has a perforated pipe running through it and has fiberglass within it but it looks like a regular muffler. When I think glass pack, I think cherrybomb or something.

here is a page with a cutout of a muffler like mine. not sure if it is the exact one that I have.

Max Flow SS Offset/Center

How's the sound and how much did it set you back? Not that upgrading from a cheap "turbo" muffler would matter for my car with its horrible system forward of the muffler...old-school pellet converter, and a ridiculous junction box with a hairpin turn in it.

It has a deeper tone at idle but it isn't overbearing. it doesn't really get loud until around 3k rpms and even then isn't that loud unless you are at WOT. I like it.

it was $350 shipped which isn't bad as I was increasing the pipe diameter as well. one good think about the yaris is it is a straight shot all the way to the axle. yea, they have to do the bendy thing to get over the rear to exit but that is typical.

it probably isn't economical for you to change your setup. the changes I made had nothing to do with efficiency or economics. ;)

The xb has a variable muffler, I think when it heats up from highway driving it makes more noise then once off the highway it cools off and gets quiet again. First time I noticed it I thought I had a pipe leak developing!

So I guess you are not trying for the sleeper appearance with the noisier exhaust system?

I wonder if the xB has the same stock muffler as the yaris. same drivetrain and all. mine looked like a pumpkin. it really looks like no other muffler I have ever seen. also a reason I wanted to get rid of it. I am tempted to cut it open to see exactly what is inside.

my exhaust is louder but I don't think anyone will be particularly attracted to it. it definitely isn't the fart can style exhaust. I knew guys that had exhausts that at idle were louder than mine at WOT. I think of it as tastefully done. there again, I'm biased.