Ok, I'm in the process of doing a comparison of the differences of warm air intakes to cold air intakes for the Cavaliers with the 2.4 or ecotec engines.
Here is what I started with.
This was my cold air intake that did me very well.
I'm doing this experiment because I have the belief that the routing of the tubes is slowing down the velocity of the intake charge to the throttlebody.
Here is what I started with first in this comparison.
I took apart the cai and went with my first intake setup I made.
I'll have all of the details of the differences between all of the intakes you see here. Nothing is bought outright from any manufacturer and all intakes are home made.
Here is the present setup with some better piping and connections and will also be used for the final cai comparison too. The picture below is brand new and excuse the engine compartment for being so dirty.
I got some extra aluminum tubing to smooth out the first bend off of the throttlebody and this will stay permanent whether I stay with the wai or cai setup.
I'll be updating this thread with more findings once they come in and have a complete report with gains, losses, throttle response, and general overall feel of the way the engine behaves with the different systems.
I'll also have findings of what the different temperatures will be with each system as compared to the original cai design. It's surprising what I found on some of the setups, which were three to date so far.
Oh, here is a picture of all of the pieces I used to make the different intakes. The second intake design I don't have a picture of but can say the first wai you see is about 1 foot in total length, the second (not pictured) was 1.5 ft in total length and the third (pictured above) is 2 feet in total length. The cai setup was a total of 4 feet in length for all to know and had good throttle response and good time with it at the track.
I'm also trying to get rid of the big, overly large rubber elbows that I was using in the cai setup and should have those eliminated for better aesthetics to the intake.
Oh, if you take a look at the original K&N filter, it's totally sucked in from all of the suction from all of the years. This is the only reason I'm using the filter shown in the third picture. It's hard to find a good K&N cone filter for the car and one that will fit.
Comparisons coming soon.
Update One
Just wanted to keep you abreast of the intake experiment I'm doing.
So far, I went back to this design below.
This was my original design about 2.5 years ago. It worked ok but had top end issues. I went with the cai and it worked better than this original design pictured. Remember, I was still with the stock 52mm throttlebody with the original design..
Now that it has been back to the old design intake system (as pictured) on the 62mm throttlebody, the car seems to have more pull than with the cai, but only at wide open throttle (wot) . Throttle response is marginally as good but have to go into the pedal more when more power is wanted, than compared to the cai setup I had previously.
A couple of theories may be working here.
First, the length of tube with the bigger throttlebody may have kept the throttle response down abit with the length from filter going to the throttlebody and second, staying one diameter, short tube seems to have a better effect with the bigger throttlebody. The same should hold true with the 52mm tb.
I have noticed some unusual intake temperature changes too since the conversion to wai.
On the cai (with 52 and 62mm tb's), the air temp remained pretty much in line with the outside air and varied no more than 10-15 degrees at any one reading whether sitting at a light or at speed on the interstate,.
With the wai setup with the filter where you see it, temperatures rise to about 20-30 degrees above outside air temperature and actually cools down when at a traffic light, then rewarms back up when you are on the move. It also gets warmer as you go to interstate speeds too, then cools down once you slow down to the 40mph mark.
During these tests, I had the fan on the whole time. I keep the fan on to keep the engine cool and only turn it off when I shut the car off. This whole testing is with the fan in the on position, cooling the engine.
The fan is drawing cooler air when not in motion, thus allowing the intake temp to drop (outside air) and when the car moves, air through the radiator is warming the intake air.
It takes about three days for the ecu to reset to the new setup and this is the third day. I've noticed improvement the last two days and like what I see.
Top end doesn't seem changed and may take a trip to the track to see if my findings are similar.
Update number two.
I lengthened the tubing (by about 4 inches) by adding an elbow to the intake (45 degree rubber elbow), and installing the filter directly on the end . My finding were a little eye opening.
Even though the intake air temperature remains25-35 degrees over the outside air temperature (as before), the throttle response has improved with this little addition and the whole power band seemed to shift a bit lower on the car. Now, I don't have to get into the pedal as much to go and is nearly similar to the way the response was on the cai (with 62mm tb). The wot response has improved, more than with the cai setup and not drawing cool air from the outside.
Length of tubing does matter and keeping it all one size seems to help the top end flow very much. Even the 1st, second shift point in the tranny has lowered as more power is available with this setup and less low gear is needed to move the car from a start.
Maybe this is why the AEM is so popular with the tuners as this design is about the same length as what I have now, only difference is that they use 2.5 inch pipe, I'm using 3 inch piping. Both intakes use one diameter piping too, not like my previous setup which had rubber elbow couplers.
I still haven't been to the track yet, but seat of the pants feel tell me the car has more power, more throttle response and great top end than the previous seutp.
Update number three.
I further lengthened the tubing with an 8 inch piece of straight pipe coming from the only bend in the setup. From there, the filter is on the end of this, now longer pipe and is near the usual place that most ppl set their filter as in the AEM application for J-bodies. My only difference is that there is no bend in the pipe to angle the filter into that little compartment area.
Throttle response = as good as the cai with 52mm and 62mm tb's.
Top end (so far) = as good but feels better, pulls harder than the cai setup for 52 or 62mm tb's.
Temperature is the same as any of the wai setups previously but is not affecting the power at all (eye opener).
I've noticed a little less variation in the temperature spikes too with the filter set in the new position. It's still about 20-30 degrees warmer than outside air (at idle) but if I have the same amount of power as the cai, will keep it in this setup for now. Tracktime coming up to see if the findings are good.
One last thing, if the tubing can remain a constant 3 inch all the way down into the fenderwell, I believe it would be a great intake for anyone that wants the best of all worlds and has the bigger tb. With the little (52mm) tb of the factory unit, seems to not have that much pull or airflow to really make the intake work as good as a smaller diameter intake pipe.
Update number four.
Well, I love the setup the way it is.
With the extension of 8 inches of pipe added to the overall intake length, it rocks.
Temperatures are now only 10-15 degrees warmer with the filter perched in the usual place that all Cavaliers place them and variations from that only go about another 10 degrees warmer when your sitting at a stop light.
Power and torque seem as good as the cai and even the tone of the exhaust seems to have gotten more aggressive than before.
I went to the track last night and did two runs.
I'm experimenting with the intake systems and went to the track last night with full interior, stock rims, tires, sound system and for once in many moons, they coated the track with VHT. I could not get the car to spin a tire at all.
My times were 16.28 for the 1/4, .64 for the r/t, 2.54 for the 60foot.
My second run was 16.12 for the 1/4, .82 ror the r/t, and 2.48 for the 60foots.
With the bigger rims and tires, couldn't get my 60 foot times down to where they usually are, in the 2.2 range.
If I had my other rim/ tires, would've been in the 15.8-15.9 range.
The temperatures were in the high 70's with very high humidities.
I'm going next week again to see what it's going to do with the proper setup for racing.
I'll then have the rims/ tires, no boom box, no seats and will hopefully get some better times.
Once that is done, I'm going to reinstall the cai and run one more time to see the differences in the wai and cai setup for the Cavy.
Right now, the times are a bit slower (about 3-4 tenths) than with the cai setup and is getting me to believe that cool air is essential for better times at the track.
Update number five
I have noted the cai was within 5 degrees of outside air temp at highway speeds, idling at traffic lights and all around town driving.
Wai intakes (as presently setup) are minimum of 10 degree difference at high way speeds and at idle, 20-30 degree, and around town, 15-20 degrees above outside air temperature.
So far, the cai has the books on what is best for overall performance (until final testing) , throttle response and getting more power (overall) in all situations listed above.
I'll still have my track day tomorrow with the last wai configuration and then this coming weekend, setup the cai once again, go to the track and make the final evaluations then.
Stay tuned for the final report.
Another note:
I've noticed improvement in the midrange power with the longer tubing of the intake.
It seems the shorter the intake tube, as in the first intake, the throttle response just wasn't there and power over the entire power band was lost.
As the tubing length got longer, the response improved with equal measure, throughout the power band, and not in any particular place in the powerband.
This current setup really has a good sound to it and the feel is so far the best of the intakes I've used. It offers the best of both world in that the intake temps stay within 10-12 degrees of outside air when moving at interstate speeds and about 15-20 degrees or a bit higher when going around town at slower speed. Power remains good but once the temperature goes higher than 105 degrees (intake temperature) , power falls flat and pull is not as hard. This is where cold air from a cai is handy, especially with stop and go type traffic
.
Final note, it seems that when you get all of the good throttle response and good midrange, your top end seems to suffer a bit.
I'll know a bit better once I hit the track tonight.
Update number 6
I hit the track in full race preparation.
The best the car ran with this last wai was 15.86 with the best 1/8 mile being 10.13. My 60 foot times were in the 2.25 and up to a max of 2.30 when the engine was a bit cool.
Power felt good and the best mph I could get was 85.7 in the traps.
Streetability is great with this intake like it is and am going to change back to the cai setup (with the newly made piping to the tb) and see how it stacks up against the wai setup I now have.
If the cai is better in overall performance and has the throttle response of this setup I now have, then I will reconvert and keep the cai setup.
If the cai has good top end but loses the midrange (which I so love) power, I'll stick with the wai setup.
Overall, this setup is almost as good as compared to the cai with the 52mm setup. The times for that setup under similar conditions were in the 15.77 with the same 60 foot times and trap speeds.
You must keep in mind too that my car has 123,000 miles on it right now and the times for the cai, 52mm setup occured when the engine had less than 100,000 miles on it. Injectors have never been professionally cleaned so this along with the wear on the engine at these miles may give the car a slower speed than when newer. This is just a theory but seems to be the case for now.
Final testing is coming with the cai and will answer some questions for sure.
Stay tuned.
Update number 7
Here is a picture of the final wai setup.
I had to cut a piece of the 90 degree elbow (rubber) to make a coupling so it would look pretty good and work better by having the two pipes meet at their ends for the best flow possible.
This is the best and freest flowing wai intake I have ever made and with another blue silicone coupler, would look like something you could buy from a store or aftermarket.
I now have the cai setup back on the car using all of the piping you see above. I did have to use that elbow that I cut again but got it to work pretty good until I can find another aluminum elbow I can modify and couple to the existing setup for the best looks and flow.
So far (a days worth of testing) the car seems to have all of the pep it had with the final wai setup.
It's now much quieter under hood and even though the power is still there, sounds are less noticeable from under hood. Even the exhaust sounds a bit muffled and not as aggressive as before.
To be honest, I liked the sound of the whole setup with the last wai setup and if there is no appreciable difference in my track times with the cai, will go back with the wai.
Intake temps are varying very little now and have constant cold air coming into the tb, unlike the wai setups.
Also, the feel of the response of the pedal is a bit muted now with the cai. Instead of the crispness of the throttle that I had with the wai setup, it feels a bit muted or more vague, probably due to the total length of tubing in the intake. Even downshifting from a higher gear is not as abrupt as before but still has the same feel of power as before, if not better, albeit a bit delayed feeling.
Track time will tell all this Wednesday and will post the final results the following day.
Stay tuned.
Final Notes
I went to the track tonight with the cool air intake and run a time of 15.84 with a 60 foot of 2.38. I had my tires at 28 pounds this time and deflated abit further with pressure down to 26 pounds. The car is making a bit more power with the cai and the trap speed was 86.5 mph.
Second run yeilded a 15.76 time with a 60 foot time of 2.29. Trap speed came out to be at 85.7 mph.
The rest of my runs yielded pretty consistent time of 15.80 - 15.84 times for the rest of the night. Temperature and humidity were higher than the previous week and checking the intake air temperature for that evening found it to be in the 87-89 degree range with high humidity.
Not bad for warmer temperatures and better times.
So the cool air intake is the way to go.
Track testing and even the last 5 runs I made yielded the car barking into second gear with so much power (relative power) on hand..
So, I'm keeping the cai on the car, love the now quieter condition of the under hood noises and have pretty much a nice even flow of power across the entire power band.
The last thing I will do is to replace the rubber 90 degree elbow with an aluminum unit and connect it all with silicone couplers to complete the new version of my cai.
I hope this gives some ppl some idea of the differences between the cai and wai intakes and what works better.
It's finally done and I'm glad.
James
Here are the pictures if you want to check them out.
