Honda Insight w/Acura TSX engine - Ecomodding

[Ecky]

Originally Posted by redpoint5

I didn’t know about the Euro Accord option. How much time would it take a noob to do the swap? It’d probably be worth it to me as I always say the TSX is nearly the perfect car except for the dumb gearing (and terrible turning radius).

Getting the transmission out and apart is easy enough, but you'd want to take the gear stack to someone with a press to get the countershaft gears off the countershaft.

[Ecky]

Honestly, I'm not certain what all is involved in removing the transmission from a TSX. The Insight doesn't have a subframe, so it's a matter of unbolting the transmission and loosening the engine mounts so it sags, then sliding the transmission off. Once it's out, taking the transmission apart isn't hard or very time consuming, except that you need a press to get the CS gears off.

[19bonestock88]

Originally Posted by Ecky

If you need a speedometer correction though, I do have a Dakota Digital converter that I no longer need.

It work on all makes/models?

[Ecky]

Originally Posted by 19bonestock88

It work on all makes/models?

Yep, it can convert low and high frequency back and forth (approximately 30-40x frequency difference), or make smaller corrections caused by gearing or tire size. Should work on any transmission from any manufacturer.

[Ecky]

Small update, the weather has been improving here, and so has my fuel economy. I'm 214 miles into a tank and have a tank average so far of 48.5mpg. This morning the weather was 39F and raining, and I averaged 51.8mpg on my way to work. Approximately 40 miles of my tank have been traveled with the engine off.

I'm looking forward to the weather continuing to improve.

[Ecky]

Recently a clunking had been developing in the rear of my car. I've been listening to it on my commute every day, and it seemed to get worse as time went on. Last weekend I put my car up on jacks and looked around underneath. I couldn't find anything obvious, so I used it as an excuse to order some new Gaz adjustable shocks to replace my 270k mile OEM shocks, in case they were clunking.

Today the new shocks came in. While I was under the car, I noticed one of my springs had broken! It was on the side where the noise had been coming from.

These springs are a popular swap for ~30% higher spring rates and come from the Chevy Spark. A while back I had spoken to the seller (Scott at Jue Motors) about them showing very premature rust - they had a serious patina after just one winter, whereas my original year 2000 springs still looked practically new. Scott went way above and beyond and sent me a new set of springs at no cost, but I just didn't get around to installing them. That was maybe 2 years ago now?

The rust looked (and still looks) entirely superficial, so I don't think I can account for the spring snapping, but today I put the new set of (uncut) springs in. Unfortunately, that didn't fix the clunking, and the back of the car sits significantly higher than the front. I plan to cut them down to get approximately stock ride height (maybe up a quarter inch or so from the old springs), but I have some custom coilovers for the front coming from Fortune for the front that I want to install first.

I had my wife drive on some rough roads while I pressed my ear around in the back of the car, and isolated where it was coming from: the passenger side bolt holding the trailing axle to the frame had loosened, and I was hearing the torsion beam clunk back and forth. I realize now I never retorqued it after I installed my rear poly bushings, and the bolt must have slowly worked loose over the last 2 years.

As a side note, the first setting I tried with the Gaz shocks was 6 clicks from the softest setting. It doesn't seem to fully dampen on the first rebound at this setting, so I'll turn it up tomorrow, but man is the ride smooth in the back.

The OEM shocks are apparently also still good. I estimate they compress about the same as the Gaz at 11 clicks, which is ~50% their maximum damping.

[serialk11r]

300mbar? I thought you said 400 before. 300 is so low!

I feel like you need to run more lean. 1.4 lambda would be a good target to aspire to, you may need to warm the air a little to make it work. IIRC you have it at 1.07 closed loop right? Why not open loop?

[Ecky]

Originally Posted by serialk11r

300mbar? I thought you said 400 before. 300 is so low!

I feel like you need to run more lean. 1.4 lambda would be a good target to aspire to, you may need to warm the air a little to make it work. IIRC you have it at 1.07 closed loop right? Why not open loop? You can run stoich (or buy a wideband w/ emulator) or a little lean in closed loop at the lowest load, rich at max load, and ultra lean in the middle below say 3000rpm.

A few days ago I noted I was cruising around 280mbar at lower speeds, even with my tall gearing. I'm basically at sea level too.

I expect you're right, I could benefit by running much more lean. I can target whatever I want closed loop, but the OEM K series wideband only reads accurately out to maybe 1.25 lambda. The biggest reason I haven't played with it more is that I don't have access to a dyno and haven't been able to squeeze any broad generalizations about ignition timing trends from the tuning groups I follow.

The Insight's original engine leaned out to around 1.65 lambda in closed loop. It appeared to add something like 20-25 degrees of ignition timing vs stoich. It had a high swirl head, indexed plugs, a tiny bore, an offset crank, and very high compression, so combustion speed was very high.

I haven't a clue about where to start my new engine at. If I leaned out to, say, 1.25, would that be perhaps 8 extra degrees of advance? 5? 12? Even if I wanted to trial an error it to a rough ballpark in some of the more commonly used cruising cells with a lot of A-B-A testing, there are literally no flat roads here - nowhere to just hold throttle steady while adjusting timing live.

If you have any suggestions, I'm happy to give them a shot. I can post the ignition maps I use up here for people to look at.

[serialk11r]

Actually yes, I was thinking about how to do this without a dyno for a while.

If you look up laminar flame velocity relative to stoich conditions, you can try to match it to a different stoich engine operating condition with identical laminar flame velocity.

For the first, there's all these charts that probably work well enough, read the number off and divide by the stoich value:
http://sro.sussex.ac.uk/id/eprint/79...%20Version.pdf

Then for the second (varying air density at constant lambda), I believe the reaction rate is approximately proportional to density squared, since both oxygen and hydrocarbon concentrations are proportionately reduced. I should probably go read some papers that take into account radical formation and whatever but it's probably good enough as an approximation, since no ECU actually has enough parameters to do this perfectly as the results are similar within a few degrees of timing.

So for example, it looks like at 1.4 lambda, laminar flame velocity is typically between 0.5-0.6x that of stoichiometric for a variety of fuels, so the ignition timing at 0.5 bar should be set to whatever the factory timing was at 0.353-0.387 bar. This actually ignores the effect of residual exhaust gas, scavenging/reversion, resonance, and temperature change from the intake to the valves, but it's probably good enough, since those effects change mixture temperature in the opposite direction as they do concentration of oxygen.

If you just stick to the original ignition timing @ sqrt(0.6)*load you're probably ok for 1.4 lambda.

[MetroMPG]

So the spring that broke was chopped down a bit?



If it's like the chop job on my Firefly & Metro, the removed coil(s) includes the last, flat loop that contacts the perch. Seems possible there's might be enough leverage due to the chopped coil angle against the perch that it fatigues over time.