Upper/Lower Intake Mods

[SergntMac]

I lifted this from another thread recently opened by Rumble relative to engine temps and chrome plating.

The problem with chrome and polished aluminum is that it holds the heat in the intake which is bad because you air isn't as dense thus a performance loss. I had a 10-15 degree coolant temp difference between polished and natural finish intake...I think the chrome look is great, did you think of doing the ceramic coating for a temp barrier instead of chrome?
Yes, it does look great, and I had the same questions on my mind for a while now. My thoughts began when discussing Reinhart's Cobra exhaust, and it's ceramic "jet-hot" coating acting as a heat barrier. Considering how deep the lower intake sits in the valley between the heads, I thought that if ceramic coating keeps heat in, it should keep heat out too, and I set out to investigate how ceramic coating the lower intake could improve combustion.

First, I sent a spare upper and lower intake manifold out for treatment by MirrorLook in Naperville Il. www.mirrorlook.com The lower intake was 100 percent ceramic coated inside and out, no other treatments, or, internal polishing. The upper intake was polished on the outside only. Both came back looking very sweet. The bonus in appearance is one thing, but what I didn't expect is how the ceramic coating inside the lower intake seemed to smooth things out just a bit. It's just an impression, whether this was going to be any benefit or not was what I had to investigate. Larry did a great job of it too.

http://www.mercurygallery.net/mmnet/showphoto.php/photo/5539/password/d746d272dfed711f349d5453ed3b71 f7/sort/1/cat/last1/page/1

Next, I ran a base line on the dyno to establish where in my powerband I was getting the best performance. I did not do your typical performance pull, but drove the car from a dead stop through to the top of third gear, to simulate a 1/4 mile run. While it's true that the 1-2 and 2-3 shifts will cause spikes in the overall RWHP and RWTQ number, I wasn't concerned about skewing those final numbers. I wanted to track where the power came on and to see if I could improve that. BTW, I track all my performance measurements directly from the EEC. Engine temps, fuel trim, voltage, ect., all with the Davis CarChip EX. External gauges and measurements are fine, but I want to see what the EEC sees, and reacts to.

My Kenny Brown Vortech supercharger delivers an air charge that is a stable 10 degrees lower than outside air at the point where IATs are measured, and my belief was that if I could keep this air colder longer in the combustion process, I should expect more power. Since there is no way that I know of to measure the air charge temp this deep in the intake process, I had to look at other areas to note any change. The best I could think of was AFR and power curve on the dyno.

The AFR was a clean 13-13.5 prior to the mods, and my engine temps have always been very stable at 180-185 degrees. After the intake was installed, and Paul's intake spacer added, I went on for the "after" dyno." The rationale for adding the spacer was simply to increase intake volume. How much power this spacer adds, is mostly opinion and seat-of-the-pants measurements, however, the whole point of supercharging is to increase volumetric efficiency, so, it can't hurt to give the air charge a little more elbow room up top.

I lost almost 10 RWHP off the top end, no big deal to me right now. My AFR has dropped into the "pig rich" 11.-12. range, and engine temps are down to 175-180 degrees. Fuel consumption has dropped to 20 MPG HYW as well. What does this mean? I'm running way rich and need to retune the engine for better performance. Considering where I was at prior to this upgrade, this is good news to me. Moreover, my 1-2 and 2-3 shifts are comming on much too soon, 4500 and 5500 PRM respectively, again a sign of a need to retune, but likewise a plus.

My engine builds power from 2500 through 6000 RPM, so, I'm not getting the best of my powerband. However, I did gain 7 RWHP at 4000 RPM, just before the 1-2 shift, and 12 RWHP at 5000 RPM, just before the 2-3 shift. I believe that if I can see that now, I know there is more to reach for with tuning, and tuning safely away from deadly detonation thresholds and running lean. BTW, I have a second knock sensor and an '04 EEC installed last spring.

My results seem bleak at this time, but I'm not done. My projection is that I will not see any great improvements on the dyno, but already my SOTP meter is telling me this was a good mod.

Was it worth it? Is there any "bang for the buck?" Ummm...Yes, it's there, but within a very thin margin. Paul's intake spacer alone seem well worth the 80 bucks, and you'll feel it in the low RPMs. The performance gains of ceramic coated lower intake and polished upper intake do not justify their combined cost of 500 bucks, but they do look great too. Labor costs are minimal, changing out the intake is a DYI afternoon project.

Next up, is actually polishing the interior of the intake, and a few other tricks. Zack's going to take that on.

http://www.mercurygallery.net/mmnet/showphoto.php/photo/5543/password/d746d272dfed711f349d5453ed3b71 f7/sort/1/cat/last1/page/1

http://www.mercurygallery.net/mmnet/showphoto.php/photo/5542/password/d746d272dfed711f349d5453ed3b71 f7/sort/1/cat/last1/page/1

http://www.mercurygallery.net/mmnet/showphoto.php/photo/5541/password/d746d272dfed711f349d5453ed3b71 f7/sort/1/cat/last1/page/1

http://www.mercurygallery.net/mmnet/showphoto.php/photo/5540/password/d746d272dfed711f349d5453ed3b71 f7/sort/1/cat/last1/page/1

[Haggis]

Looking sweet Mac, real sweet!! But, I think I will have to pass, Chris would kill me. LOL!! Who knows maybe someday a guy can dream...:cloud9:

[FordNut]

Great progress. I'm planning some similar intake treatments myself, so we'll have several data points for comparison! It really looks sweet.

[BillyGman]

Very interesting report here. It isn't anything that I'd be messing with, but that's a matter of preference on my part. It sounds like much of this report was honest since you've pointed out some possible downfalls w/it such as cost vs. results. So I commend you for your honesty. You've taken a bit of a gamble in doing this as would be the case w/most experiments, but I think it's good that you're willing to be realistic enough about your approach to admit any negative points about the results.


One thing that I'm a bit curious about is why would any of this have caused the AFR to run richer than it was before? I suspect that it's likely due to one of two reasons:

# 1. Some changes occured in the intake flow which are throwing off the Mass air sensor, which in turn causes the computer to incorrectly read, or change the air/fuel ratio.

# 2. Or you're actually getting less air into the engine than you were before. (I don't know how or why that would be the case though).

my guess is that # 1. would be the case, no?

[rumble]

Sarge, very interesting and thanks.

For what it's worth, I chose not to change the lower intake because
I did feel that it would be more prone to heat issues than just the upper. Also originally I had the intake only polished but then since I had the valve covers chromed and installed I felt that they didn't match so I went ahead and chromed it also. Another reason I only did the upper was changing it out was a piece of cake compared with doing the lower also.

[CRUZTAKER]

Wow!

Mucho taking apart of things....but the appearence is well worth it. Nice!

[bugsys03]

Hey Mac- looks awesome. IMO probably worth the $500 just for the bling effect. ;)

[jgc61sr2002]

Sarge - Looks great. :up: Thank you for the excellent report.

[cyclone03]

Mac I'm wondering if your performance chages might have something to do with grounding of sensors,or lack of, due to the coatings?
I don't know how well those coating conduct.


I also wonder how much heat is picked up from the valley under the intake?
Your coating would block that very well.

BTW that intake looks great!

[Warpath]

Very interesting report here. It isn't anything that I'd be messing with, but that's a matter of preference on my part. It sounds like much of this report was honest since you've pointed out some possible downfalls w/it such as cost vs. results. So I commend you for your honesty. You've taken a bit of a gamble in doing this as would be the case w/most experiments, but I think it's good that you're willing to be realistic enough about your approach to admit any negative points about the results.


One thing that I'm a bit curious about is why would any of this have caused the AFR to run richer than it was before? I suspect that it's likely due to one of two reasons:

# 1. Some changes occured in the intake flow which are throwing off the Mass air sensor, which in turn causes the computer to incorrectly read, or change the air/fuel ratio.

# 2. Or you're actually getting less air into the engine than you were before. (I don't know how or why that would be the case though).

my guess is that # 1. would be the case, no?

I agree with Billy and cyclone03 - Something doesn't seem to add up. If your theory was true, you should be leaning it out. It makes me wonder whether the uncoated intake allows the intake air to cool further and the coating prevents that (if Billy's and cyclone's theories are untrue).

I suggest doing another run w/o the spacer so you have a direct A to B comparison.

It must be nice to have enough money to play around with stuff like this. :)

[SergntMac]

I agree with Billy and cyclone03 - Something doesn't seem to add up. If your theory was true, you should be leaning it out. It makes me wonder whether the uncoated intake allows the intake air to cool further and the coating prevents that (if Billy's and cyclone's theories are untrue). I suggest doing another run w/o the spacer so you have a direct A to B comparison.
Thanks, Warpath, I'm exploring a theory of my own, and FTR, I'm still exploring it, and I'm open to ideas. Though polishing the upper intake was strictly for bling while I had the chance, I cannot help wondering if that fact may have had some effect on the results I have discovered so far.

Could polishing the outer surface contribute to a cooler air charge? Before this experiment, I would have said no. But now, I'm not so sure. It could serve to reflect, rather than absorb, ambient engine bay heat. If this is the case, I am considering ceramic coating the entire air path to ward off engine bay heat. This would include the short intake pipe with the MAF connected (see previously posted pics) the water to air intercooler, and the blow pipe prior to that (when my "whistle" is mounted). These parts are presently powercoated. Please remember, this isn't over, it's just beginning.

As for removing the spacer and trying again, I can do that, but I don't expect the spacer to have any effect on air charge temps. Maybe later in the exploration I'll back up and pull the spacer, but it's performance has been independently researched by others, and I expect no relationship between rich AFR and the spacer.

I appreciate all the compliments on the bling, and I respect the advice offered. Some goes against thoughts I have in mind, but I'm not beyond changing my mind either. I'm not disagreeing, they are possible. I'm just sifting through probability...A) The MAF is just another sensor, perhaps the last sensor in line before IAT. If the IAT and MAF work together to set the air charge, their job is done at that point, and the air charge has still to get to the combustion chamber via the "maybe cooler" intake. The next sensor in line is the knock sensors, which report detonation. If detected, the air charge will change.

However, and more in line with Billy's #2 suggestion, less air may be the key. If the air charge gets through the intake(s) cooler, the air charge will contain cooler (i..e. more dense) air, and the charge will burn rich. This was my expected outcome, and based on the fact that no other changes have been made in tuning, and it's running rich. So (shrug) I have to work with that until I find out otherwise. What else could it be? And, if it stays rich, I should be able to retune and take advantage of other conditions, perhaps restore some minor, but lost power.

BTW, all wires and connections have been verified, if something critical was not correct, I would expect an "on-off" result with obvious results such as shut down, or, MIL. Nothing, nada, but I'll keep an eye on it, thanks.

Did I miss a sensor network somewhere?

I'm also wondering if the post combustion O2 sensors are at play here? If a rich burn was detected, would they not send a signal to lean out?

I'm guessing on most of this, all thoughts are welcome.

[BillyGman]

I all this type of stuff can get real complicated w/the hi-tech computer controlled engines these days.So I will NOT make any claim to have any of this all figured out. I'm simply speculating as everyone else is here. Actually though MAC, I would think that if the air is cooler, and therefore denser, then if anything, it was cause a leaner condiction rather than a richer one. That's what I believe Warpath was getting at too.


And as far as the spacer goes, if it's made out of Phenolic like some carburetor spacers are, then it can cause a cooler air charge since it prevents some of the heat of the heads and/or engine block from transfering to the intake manifolds (atleast that's what the threory has always been). Just food for thought MAC.

[SergntMac]

Actually though MAC, I would think that if the air is cooler, and therefore denser, then if anything, it was cause a leaner condiction rather than a richer one. That's what I believe Warpath was getting at too.
Ummm...Okay. I need to learn more on this, I predicted the opposite.

And as far as the spacer goes, if it's made out of Phenolic like some carburetor spacers are, then it can cause a cooler air charge since it prevents some of the heat of the heads and/or engine block from transfering to the intake manifolds (atleast that's what the threory has always been). Just food for thought MAC.
I'm not sure what's it's made of, but appears aluminum. But, the heat exchange you suggest is something I did not consider, that the spacer could be an additional insulator. Good suggestionl, Billy, thanks. Maybe I will pull it, see what happens then.

[cyclone03]

Mac the heat pick up in the upper would be the egr valve,it is open under most cruise positions but closes under WOT. The water lines in the intake may help spread that added heat some too.

I guess I missed something,is your intake polished or coated or both?
I also tend to forget your S/C ed.So MY GUESS is your charged air temp at the valve(like we could measure it) is still the same (100f ?).
That said pushing 100deg air through a 100deg passage has to be better than pushing it through a 150deg passage.

You say your running rich, time to go KISS method.
Make sure every cylinder is firing.
Is the vacuum line properly connected to the fuel pressure reg?Is it working?
Fuel pressure?
sometimes we get caught up in the electronics and forget the mechanicals.

SOMETHING changed I don't think a 20-30deg drop in charge temp would make the car go pig rich,or it would run like crap everytime the sun went behind a cloud.

Remember how well we run when it gets cold out. Denser air+more fuel=more power.everytime. any time we cool the intake charge the CPU balances that with more fuel.

I think your right to go to the O2 sensors.

I still think your intake is the cats...socks.

[cyclone03]

Ok I read the above again,your running(or showing) low water temps.The CPU thinks your cold (choke mode)
try touching a ground wire to the water crossover and a good ground and see if your temp reading goes up.

I have trouble believing a coated intake would drop the water temp.
Your bad mileage is also a clue.
Thermostat stuck open?

Remember K.I.S.S.

[Warpath]

I all this type of stuff can get real complicated w/the hi-tech computer controlled engines these days.So I will NOT make any claim to have any of this all figured out. I'm simply speculating as everyone else is here. Actually though MAC, I would think that if the air is cooler, and therefore denser, then if anything, it was cause a leaner condiction rather than a richer one. That's what I believe Warpath was getting at too...

'Tis true. Hotter air is less dense for the same volume. Since your MAF and IAT measure air before the intake, it does not know what is actually in the intake. Therefore, it will supply the same fuel for the same ambient temp and air flow. If you are running rich and knowing the fuel flow rate is the same (assuming the same ambient temp & air flow rate), that would mean you have less air than before => intake air is hotter.

I suggested doing a run w/o the spacer to make sure it doesn't do anything. It is an added expense. But, it at least answers the question.

Polishing the outer intake surface could result in lower intake temp as you suggested Mac. But, only when comparing it to a painted surface. As long as the surface is shiny, it may reflect heat compared to a painted surface. So, the surface doesn't need to be smooth, just shiny - at least in my mind.


Ok I read the above again,your running(or showing) low water temps.The CPU thinks your cold (choke mode)
try touching a ground wire to the water crossover and a good ground and see if your temp reading goes up.

I have trouble believing a coated intake would drop the water temp.
Your bad mileage is also a clue.
Thermostat stuck open?

Remember K.I.S.S.

cyclone may be on to something. Did they coat the entire intake including water passages, if they exist? If so, the coating may be preventing the coolant from cooling the intake which would result in cooler coolant and warmer intake. That would agree with the warmer intake charge theory.

[SergntMac]

Thank you all, you are all very helpful here.

I won't be able to get back on the project until later this week, but I will keep y'all posted. Here's a few quck replies to your thoughts, sorry I cannot trrack who asked.

Engine temp drops are not 25-30 degrees severe, but from a steady 185 to 177-180. MPG has dropped 2-3 on the highway. City is about the same, just plain pizz poor due to my driving habits.

Upper intake is polished on top only, not internally. Lower intake is ceramic coated inside and out. No water jackets running through the lower intake.

I suspect I'm running rich from dirty O2 exhaust sensors, they may be off a bit, I'll pull them and check.

Keep other results in mind, a loss of 10 or so RWHP off the top end, but gains of 7 at the 1-2 shift, and 12 at the 2-3 shift. I'm not concerned with the totals, but where in the power curve it's making more power. Also have to reset my shift points, 1-2 at approx 4500 and 2-3 at approx 5500 is much too soon and probably where I'm spending that 10 RWHP. Also touching up my knowledge base on the AFR/dense air stuff too.

Thanks again, keep y'all posted.

[Warpath]

I forgot to add that the O2s closest to the block & before the cats regulate A/F. The O2s closest to the mufflers and after the cats check emmisions. So, if the rear O2s are giving funny readings, I would think you would get a check engine light and a code related to emmisions. If the fronts are acting funny, who knows....

[bugsys03]

His rear O2's are non-operational

[SergntMac]

His rear O2's are non-operational
Your are correct, Dave, Thanks. My MM has four O2 sensors, two before the cats and two after. All are present and connected, but once you get "Jerry Tuned," the two rear sensors (after the cats) are shut off in the EEC. It's the two before my high flow cats that I am concerned with.

BTW...Went back to "AFR-101" this afternoon, y'all are right. Cooler air inside the intake after any sensor management, is more dense and likely to cause the AFR mixture to lean out. I am running rich now, which means that I may have stumbled into another problem I didn't expect, when I thought things were healthy.

Still tracking this down...Thanks again.