intake temp mod (and the dyno proof of HP gains)

[BrandonsBlack04SRT]

Quote: Originally Posted by WhatsADSM

BTW, I agree with you 100%. The resistor AGP sent with the pipe is simply too large. I read one of your older threads about that very thing and I believe it is part of the reason the PCM is too agressive in my setup (because it sees lower IAT temps). So thanks for the heads up! I actually will be puting a 10k potentiometer in series so that I can turn it up or down as needed.

No problem, I am glad someone reported back that actually read what I had to say

A potentiometer is a good idea, I'll have to look into that too hehe.

[blackbird_R/T]

Quote: Originally Posted by westrock

If the PCM goes into open mode when WOT, it will never know the air fuel ratios either before or after.

But if it's going off tables such as the fuel trim cells and they get altered it may correct for it somewhat even at WOT. Without knowing the PCM programming we can only guess or test and reverse engineer what its doing.

I don't think anyone is getting too defensive, just discussing. The curves on the car do look somewhat odd but I bet the results would be comparable on another car. It would be nice to what happens on a properly running car. I'll have to put some thought into the potential effects and the pro/cons of it on my drive home tonight. It isn't exactly like a manual boost controller, MAP clamp, etc., but the results may be similar. As for the A/F it was just a comment that you might be careful about running over 12:1 on a dyno with any type of modification including this one. Right now you don't have the fuel to support that extra boost (and even more so out on the street).

And timing is important, particularly on a car that's already heavily modified and might try something like this. For example, if for some reason someone tried this in combination with a MBC they could already be running lean and the decreased timing would increase EGT's, which would increase the chance of knock. Everything affects something else and is in itself being effected upon.

I don't care only what vendors say and their testimonials and dyno graphs, but I like to see the overall picture of how an engine is running and how it's making the power. That's why I would like to see how the IAT is affecting timing in addition to the effects on boost, A/F and overall power. More knowledge makes it easier to figure out the cause—affect relationships. Keep up the good work and post what you find. Perhaps someone in your area with a scan tool can help find out some more insight in what's going on. The last car that I tried to trick the PCM via IAT changes turned out to not to even have any of the O2 sensors plugged in! And it was running surprisingly well with like that with a big turbo and S-AFC.

[ac_srt4]

First I MUST MUST agree this is a very brilliant thought!
Meanwhile I have a little doubt here:

When I use MCB or any other way to increase boost, the PCM will know the current REAL temperature and the boost it's having, therefore PCM can delivery sufficient amount of boost (assume you have to correct fuel mods)

When I use the fake intake temperature mod. PCM will assume current temperature is 120-140F. So I guess it will just increase boost without increase fuel, since higher temperature gives you less dense air -> less oxygen.

Overall, I am gussing the difference here is other boost mods will not fool the PCM at least, then right amount of fuel can be injected. Here PCM "may" not giving more fuel even though the boost is increased, since it's "much hotter".

However I do agree factory fuel system runs very rich, but my point here is that if you see 15psi when you do this mod, it may not be exactly the same as 15psi via other boost mods.

I am not a professional in car systems, here is only my thoughts. I will be very much appreciated if someone can correct me on this.

Tiger

[nocturnalsrt]

wont the ecu still watch the a/f sensor and add fuel if it starts to run a little lean. also is this not similar to the people that run water/meth injection systems that spray after the temp sensor? the ecu does not see the lower temps in that case as well.

[ac_srt4]

Quote: Originally Posted by nocturnalsrt

wont the ecu still watch the a/f sensor and add fuel if it starts to run a little lean. also is this not similar to the people that run water/meth injection systems that spray after the temp sensor? the ecu does not see the lower temps in that case as well.

hmm.. makes sense.. has anyone used wideband to see the ratio on this mod yet?

[csufdrew]

Quote: Originally Posted by ac_srt4

hmm.. makes sense.. has anyone used wideband to see the ratio on this mod yet?

are you kidding me??? Did you see the graph posted? Not something I would want to be driving.....


PCM found out what happend, and you lost ~40whp & 70 ft/lbs torque

[Orange Blast OC]

Quote: Originally Posted by csufdrew

Quote: Originally Posted by ac_srt4

hmm.. makes sense.. has anyone used wideband to see the ratio on this mod yet?

are you kidding me??? Did you see the graph posted? Not something I would want to be driving.....


PCM found out what happend, and you lost ~40whp & 70 ft/lbs torque

You're absolutely correct! After the huge HP/TQ spike, the PCM says, "Oh, shit!" and quickly pulls everything back.

[spool4u]

subscribed and bumped

[2.4 litre kreeder]

Bump, need some wizards now dasmopar, aaronneon, dansrt4, vector maybe??

[srt-4Sonny]

Quote: Originally Posted by 2.4 litre kreeder

Bump, need some wizards now dasmopar, aaronneon, dansrt4, vector maybe??

x2 but this graph is looking iffy.

It did make power but these cars figure thing out very quickly, then they slap you in the face for trying to pull one over on them....


Maybe some of our tuners could give there thoughts... Not trying to shoot the guy down that actually did this....

[westrock]

Quote: Originally Posted by srt-4Sonny

Not trying to shoot the guy down that actually did this....

No offense taken! I've got a 50 trim installed now and am using a manual boost controller.

When I took the stock turbo off I noticed I did have a pretty poor seal where the downpipe mated to the O2 housing....3 sides of the flange were covered in soot. That may have affected the way the car spooled up.

I really don't see how the car would be any wiser. It looks at intake temps and during WOT uses a predefined map of how much fuel to use and ignores the O2 sensors. Unless it looks at the RPM and says "hey the car is accelerating faster than it should be" I don't see how it would know that its making more power than normal.

It was an idea that I had, I did it, I came back with the evidence. Now its your turn to decide what you do with that information.

However I can't stress how important O2 wideband would be.

[cali]

Quote: Originally Posted by westrock

When I took the stock turbo off I noticed I did have a pretty poor seal where the downpipe mated to the O2 housing....3 sides of the flange were covered in soot. That may have affected the way the car spooled up.

exactly.

The before and after curves look just as nasty, so it is comparable grain. They are both equally nasty.

[b16civicmatt]

The wideband used on the dynojet dyno is a highly inaccurate "sniffer" type of wideband that uses a vac to pull exhaust gases through a scrubber and then a sensor. Not only would I ever tune by that, I would never use that for saying any mods you have done are within a safe range.

Put a real wideband on a car if your going to try this, chances are that graph is with the car very lean and could explain alot.

[Mana4real]

This is very interesting and it does make a lot of sense. I just wonder the effects it has on timing. When our car has a higher intake temp, doesn't it back off timing? So us guys in cali, for example, if we used this mod we would only have 91 octane to protect ourselves. Not only would it run more timing seeing the lower intake temperatures, but it's also running leaner which may lead to detonation on 91 octane. I am just throwing some stuff out there. What do you think? You have my attention.

[macsperformance]

First of all westrock... I give you a for the research you have done!

Great Job!


Although the car seems to be experiencing an event, the graph posted is very indicative of an inertia dyno. If you guys notice the smoothing factor is turned all the way up also. Unfortunately I can not give you guys a conclusive answer as I was not present at the time of the testing.


Guys remember, so many variables can come into play while dyno testing. Even while doing back to back runs. This type of test is really subject to so much speculation. Even with this type of wideband you can all see the corresponding drop in A/F's (rich) at the bottom of the graph! All of these factors have to be taken into consideration.


One more thing.... WOT or a vehicle (current although about to change) in Open Loop will not correct for changes made to the car. The ECU will run off of the preset tables stored in its memory. Keep in mind testing such as this will not cause the car to deviate for the stock fuel or timing mapping but will bring into play additional correction tables. Although fuel trims will change at WOT the ECU will not correct in Open Loop operation (02 sensor feedback will be acknowledged but not acted upon by most ECU's).


Good Work westrock!
Chris Macellaro