-   EcoModding Central (
-   -   Daox's 1997 Paseo Build Thread (

Daox 01-18-2008 12:49 PM

Daox's 1997 Paseo Build Thread
Alright, its time to lay out the plans and mull it over with you guys for a little refinement.

I am starting with my modified 1997 Toyota Paseo.

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 (1.75" is stock). 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. I'd love to see mid 50s out of it and I think thats quite possible especially considering the temperature this time of year.

So, where do we start? First off is probably aero 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. However, any suggestions in this area are very much welcome! I don't know too much about aerodynamics (yet), so help here would be great.

The second area of interest is engine work. I need to do something to get low rpm torque back up. As it is with the ported head and throttle body, plus high flow exhaust, my low end power is sorely lacking.

To remedy this I have already purchased a stock throttle body. It is the stock 45mm, vs my bored 50mm. This should help plenum filling at lower rpms and increase torque accordingly.

The next thing to look at is the head. The porting job IMO is what is the largest contributor to my lack of low end power. The shaving that was done helps counteract it, but not enough. I have yet to find myself a new head to work with, but already have an idea of what I want done to it. The head will be treated to some special work. It will be shaved again to increase compression and thus increase low rpm torque. In addition to that it will have some port work done to it to increase in cylinder air/fuel mixing thus allowing even higher compression without the worry of detonation.

With the following done, a 2" high flow exhaust will definitly not be needed, nore desired. So, the 2" exahust will be replaced with a 1.75" exhaust. I still think this will be a bit larger than I will need, but I have had a hard time finding exhaust components for smaller pipe sizes. Some help here would be great as the Metro engines must use smaller exhausts. This brings us to the header. A header will increase the effeciency/torque of an engine versus the stock exhaust manifold. A header designed for low end torque should do quite well and I am looking into making one. The current header is a 4-2-1 type with 1.5" primaries, 1.75" secondaries, and 2" collector outlet. Its honestly a piece of garbage. Its loud and obnoxious. I do have another header for the car that is a 4-1 design. Its primaries are also 1.5". I don't know if this is the way to go either. I'd much rather design my own 4-1 header and use small 1.375" or even 1.25" primaries. This would be ideal, but we'll see how the other things pan out.

To top all this off, I would like to regearing the car. The Paseo's current transmission has the engine turning 3100 rpm @ 65 mph. I can get my hands on a differential that will drop that down to 2750 rpm @ 65 mph. This should help out on the highway quite a bit I would hope.

I know this is a lot to take in, and thanks for reading if you've actually gotten this far. Any suggestions would be great! I'll be updating this post as I go along. I like to take lots of pictures too so expect to see them as well. Just don't expect any of this to happen fast. :)

SVOboy 01-18-2008 04:07 PM

Very detailed and well written. It sounds like you've hit on everything I would mention.

Can you really not do better than 2750 rpm @ 65mph? If so that kind stinks, but it still sounds better than your current configuration.

Are there any models of this car or similar cars with better EPA ratings? If so my advice would be just to steal as much as you can from that car, :). That's pretty much what I've done, but then Hondas are likely more interchangeable than toyotas.

Looking forward to your progress!

Daox 01-18-2008 05:00 PM

I could get the rpms lower, it would just mean getting a new transmission. The plan is to swap a Corolla transmission into the Tercel in the near future due to its modifications. That'll leave me with the Tercel's 4 speed tranny with a 3.526 differential. If I went with a 95+ Tercel tranny it has a 5th gear ratio of .725 versus the Paseo's .815. That would bring the rpms down to 2450 @ 65 mph. But, that means buying a tranny. Also, the Paseos tranny only has 70,000 miles on it and still shifts quite smooth. I'll have to look into it. It would be nice since I could do the work before hand with the new tranny out of the car, and then just swap them.

What rpms do the VXs turn @ 65mph?

Paseo trans.

1st 3.545
2nd 1.904
3rd 1.310
4th 0.969
5th 0.815
Diff 3.941

93 Tercel trans.

1st 3.545
2nd 1.904
3rd 1.233
4th 0.885
Diff 3.526

95+ Tercel trans.

1st 3.545
2nd 1.904
3rd 1.233
4th 0.885
5th 0.725
Diff 3.722

SVOboy 01-18-2008 05:04 PM

Interesting. How much do those transmissions go for? I got mine for free, :D

Daox 01-18-2008 05:06 PM

I wish I was so lucky.

I just checked out (great site btw) and found one for under $100. But, its in Ohio, and I'm sure shipping wouldn't be pretty.

SVOboy 01-18-2008 05:09 PM

Last time I shipped a tranny it was about ~60 dollars, I think. If you open use a DHL account you can do pretty well shipping wise. I would poke around on ebay and toyota forums. At least in the case of hondas, the performance types are always swapping out their old stuff and leaving it laying around.

roflwaffle 01-18-2008 05:58 PM

Check up on enthusiast sites/ebay/craigslist/etc... You can find cheaper. I've picked up a couple (4&5sp) free transmissions for my VW and recently bought one with what I felt were great ratios for $80 shipped.

Coyote X 01-18-2008 06:21 PM

If you have shaved the head the cam is now retarded from it's stock location. On a metro it is about 1 degree per 0.020 shaved. It should be similar on any over head cam inline engine. I would say to increase your low end, advance it a few degrees past stock. If you can get an adjustable cam gear that would be perfect to figure out where it is best at. The more advanced the cam the more it favors the bottom end. Up to a point anyway ~5-10 degrees advanced on a standard metro cam is good but on your car I have no idea.

If you have the stock cat on the exhaust it probably isn't really affecting it that much. If the cat is gone having a bit of back pressure will help the bottom end out. Maybe just crimp a pipe so it is reduced by maybe 1/4 of it's flow. The farther away from the engine the restriction is the less effect it will have and the bigger it will need to be so try and get it reasonably close.

Also weight reduction is always a good thing so consider if you really need all the stuff that is in the car now and take out what you don't.

Daox 01-19-2008 12:52 PM

Unfortunately, there is no adjustable cam pulley avaliable for the car. I'd have to have one custom made which is a possibility and I have looked into it somewhat. Another thing with it is that there is only one cam pulley, but it is a DOHC engine. The two cams are geared together under the valve cover. Retarding one retards both. So, it acts the same as a SOHC would with an adjustable cam timing pulley. Here is a picture of the cams. The cam timing pulley goes on the end of the exhaust cam which is the one on the top.

The exhaust that is on there now is totally custom. There isn't a single piece of the original left. The CAT is 2" along with everything else.

I'm real interested in weight reduction. There isn't much that can go from the car that I'm willing to part with. I do like what little sound deadener I have and I'm not stripping interior panneling. The car weighs in at 2075 lbs (941kg) curb weight which is reasonable.

MetroMPG 01-25-2008 11:08 AM

I missed this thread starting. Jumping in late...

Any progress to report yet?


Originally Posted by Daox (Post 5985)
So, where do we start? First off is probably aero 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. There isn't a whole lot of area up front to block for the grill, but I'll be looking into that as well.

I'd be looking into the grille block as item #1. You did a great job on the Matrix - can't wait to see what you do there :D (no pressure!). I think you'll be surprised at how much you can block without affecting engine temps in normal driving conditions. I'm at approx. 24 square inches of opening, and believe I could go smaller yet.

Considered a passenger side mirror delete? It's rare that we get to reduce A and improve Cd at the same time, but that's what you get by doing that.

I was reluctant to ditch mine at first, and then thought, "half the cars I've owned didn't have them in the first place, and I managed OK." You have to adapt your driving of course.

All times are GMT -4. The time now is 01:38 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright