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Discussion Starter · #1 · (Edited)
I figured I could post a new project thread over here. You guys don't get too many of these.




I've had the Paseo a few years now and have done several modifications to it. The 1.5L 16V engine currently has a shaved and ported head, bored throttle body, underdrive pulley, cold air intake, and a header with performance 2" mandrel bent exhaust. I built it to get more power out of it, and that was fun. But, now its time to get more mileage out of it.

If you click my signature and/or look below you can see that I'm averaging mid to upper 40s out of the car as is in winter conditions. The last tank was a hair above 50, and the goal for this summer is 60 mpg.





So, where do I start?

First off is probably aerodynamic mods. They are cheap and easy to do. The car sees 95% highway as its my daily commuter vehicle, so this will be the most cost effective place to start. I am starting with something that is reasonably good with a drag coefficient of .32 and a frontal area of 19.0ft^2 (1.77m^2). I'm thinking of mosly using a bellypan of sorts to smooth the underbody airflow. There isn't a whole lot of area up front to block for the grill, but I'll be looking into that as well. There is a possibility of rear wheel skirts, but I'm not sold on this just yet. I've also been looking at GM's EV-1 electric vehicle with a Cd of .19 and looking to immitate its front bumper to some extent. Some aerodynamic testing will need to be done to see where flow seperation occurs. The rear spoiler may have to go. I'll also looking into front wheel air deflectors once the belly pan is done.





Of course there are other areas to work on too. Here are a few other things I'm looking into:
refine driving technique
remove underdrive pulley (did this last weekend actually)
go back to stock throttle body (already have this, just need to install)
new exhaust (will definitly have this come summer)
stock or new intake
new head with some port work done
regearing




The first 'mod', if you want to call it that, was actually done a few weeks ago when I put the underbody panels back on the car. I had remove them a long time ago when I was doing engine and exhaust work and never put them back on. Unfortunately, its so freakin cold out I didn't do any before and after coast down tests to see the effects of the panels.

Stainless fasteners... priceless in Wisconsin's salty road conditions.


The panels.


Before.


After, and a bit more aerodynamic I'd imagine.
 

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Discussion Starter · #2 ·
Interesting discovery. I've finally gotten my scangauge back from being upgraded, so I put it in the Paseo. Water temp was a big thing I wanted to monitor with the vehicle so I could see how far I could go with grill blocking. To my amazement the car is running at 190-200°F already! As far as I know it has a 185° thermostat. I'm not sure what temp the fan kicks in. I'll have to look that up in the service manual tonight and double check the thermostat temp.
So, it doesn't look like I have much room to work. However, I plan on making room to work. How? By improving the efficiency of the stock setup. Currently, air enters the front bumper through the main opening, and two small side openings. It then goes wherever it wants and runs into many different things. I'm thinking that I will add some deflectors inside the front bumper to direct airflow directly over the radiator. This would stop air from going around the radiator and thus provide more consistant cooling. The image below is a top down view and kind of shows what I mean. The two small outer vents will eventually be covered.

 

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Discussion Starter · #3 ·
So, I was reading Hucho's Aerodynamics of Road Vehicles on my lunch hour and came across a very nice little chart that plotted rear vehicle taper angle (off horizontal) versus Cd. Of course my own car immediately pops into mind and I must measure to get a good idea of how bad things are. Well, it turns out things AREN'T very bad at all! I went and grabbed a side view of a Paseo and popped it into my CAD software. Looks like my rear windshield angle is roughly 16.7°. According to the chart the optimum is very near 15°. Hurray for the Paseo for being pretty darn close.


Of course, this brings up the idea of rear spoiler removal... we'll get to that later. ;)
 

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Wonderbread
Toyota Tercel, AE86
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Would less air-flow under the car help? if so you could lower it, plus it would look cool:thumbup:
 

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Wonderbread
Toyota Tercel, AE86
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Whenever i ask some people say yes and some say no, would those springs work on my 91 Tercel. i wanna lower my car because i miss the better handleing now that its riding high again, and i need something moderatly priced.
 

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That Acura Guy
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You can actually keep those mods on it. They will give you better MPG, because it makes the car more efficient.
 

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Discussion Starter · #14 ·
I haven't got it completely hooked up yet. I just got it running with the new injectors and emanage ultimate last fall before the snowfall. I didn't even take it out on the street (the supercharger wasn't hooked up anyway). I didn't work on it much over winter. I'm waiting to get a new tranny so I can drop the TRD LSD in it and finish up the dashboard so I can mount my gauges for tuning. Theres lots of little things to finish up too of course. It'll be very fun once done though. It won't have massive horsepower. I'm guessing it'll be around 130hp, so similar to a 4E-FTE. But, it'll have incredible low end power. Anytime you stomp on it you'll have full boost pressure. No waiting for spooling. That was the goal of the project.



As for the Paseo, I finally got a chance to look through the service manual. According to it, the thermostat should start to open up at 176-183°F. So, it looks like I'm going to be needing a new thermostat.

I also looked up at what temp my fan kicks in and its no big surprise that its on at 201°F. This is about the max temp I have hit so far. So, it sounds like my fan is probably kicking in quite a bit. I wish there was an easy way to monitor when its on vs off. I thought about splicing in a relay that powered a light, but I'd rather not cut into the wiring. In any case, I need to get the temp back down so I can go ahead with the aero mods and such.
 

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Ninja-rator
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Nice!... I want to do aero mods someday, but as of yet, car is still too new for me to touch. Maybe an airdam or two later this year to start.
 

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hey I took your poll before seeing your build . cool build . If your into aero mods then your spoilers got to go along with those wheels. go for the lightest wheels you can order and look at a lot of tires (mostly at the weight of the tires ) but also the maximum air pressure of the tire your putting on the lighter rims.
 

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Discussion Starter · #19 ·
Well, it got above 40°F today, so I was out working on the Paseo. I took a lookg between the bumper and the deflectors I had initially planned on making are going to be a bit tougher than originally thought. The contours inside the bumper cover are not exactly easy to replicate. There is also no way to mount the deflectors. Here is why. The red line indicates where the deflector would go. On both sides there are a few obstructions.


So, I'm going to need to think about how I'm going to do those some more.
In the mean time. I did something else that'll also help. I took some of our favorite piping insulation and stuffed it all around the radiator so as to create a seal around it. Now, very little air should be able to go around the radiator instead of through it. This should reduce the amount of air needed to pass through the grill, and allow me to close more of it off. Here are the pics.
Before. Its hard to see, but theres roughly a .25 - .5 inch gap between the radiator and the support member.


After.


Before.


After.


Before.


After.



This is by no means a replacement for the deflectors. As you can see in the 2nd to last picture there is a big opening where the headlight is (look in the lower right). The deflector would go between the radiator and headlight opening so air can't just go through that hole. However, its a start. It'll be interesting to see if this has any effect on the coolant temperature.
Speaking of coolant temperature, I picked up my 192°F thermostat (180°F is stock) this Saturday when I was out and about for emissions testing. I'll have to get that in, but I would like to see what this does to the setup as it currently is.
 
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