I was utterly shocked to see an average 10-25 degree drop in intake air temps, as well as a 5 degree differential between head/manifold exterior temp go to 50 degrees!!!
I should be getting an H22 spacer soon, and will do a writeup for NTPOG. The S2000 data won't translate exactly, but the Prelude should see a temperature decrease in the same ballpark. For the money, it's the best power mod I've done so far.
Kinda like that ventulli plate thing Spoon has for ITR's and civics. It also is supposed to reduce intake temps. I would also like to get more info on that spacer, good mod.
For the Prelude doesn't the Hondadata spacer block the EGR? According to the Helms this would throw a MIL because of insufficient flow in the EGR. Has anyone removed the EGR successfully before?
__________________ David Rierson
Marcucci Motorsports
98 Prelude #53 NASA Honda Challenge
03 Acura RSX
04 Nissan Armada
06 Kawasaki KLX250S
He has a Fluke dual input pyrometer. Much more accurate than the stock IAT, as I doubt the factory IAT is calibrated.
By the way, I plan on installing one on my H22 (with the EGR passage).
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Billy - 98 Prelude
#27 H2 NASA TX HondaChallenge
#27 PTB NASA TX Performance Touring Racing makes heroin addiction seem like a vague wish for something salty. -- Peter Egan
I don't think it will hurt anything. I will have to see how it works with the EGR blocked.
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Billy - 98 Prelude
#27 H2 NASA TX HondaChallenge
#27 PTB NASA TX Performance Touring Racing makes heroin addiction seem like a vague wish for something salty. -- Peter Egan
Originally posted by 71dsp as I doubt the factory IAT is calibrated.
What do you mean by the sensor not being "calibrated?"
I know of a chart in the Helm's manual showing a defined variation in IAT sensor resistance as a function of a change in specific air temperatures. If that doesn't show a calibration, then I must be confusing your definition of "calibration."
im running the hondata phenolic spacer now. have been for 3 or so months.
the egr passage IS blocked on mine. egr is still hooked up and i haven't had any problems with cold starts, idle, etc. i haven't had any real good runs with it since i had tranny work to do and now she's getting her body done.
i was however able to better my embarrassing best of 15.2 to 15.1. i shall let you guys know as soon as im able to get some more runs in(next year). but i've added the flywheel since will be almost impossible to view what the spacer has given me.
i admit i was a little conserned about the blocked egr. i had considered opening the passage. i can still do so, but i dont see the need right now. i'll also try to smog test my car, just cause im curious. PA regulated test results last time weren't too nice. but now that my paint will be done and the new front end i dont think i can get onto our above ground dyno
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vern - 93 jdm 2.3vtec 4ws
please say a prayer for isai perez jR, my godson 9.28.02-3.16.03
for God so loved the world that He gave His only begotten Son,
that whosever believeth in Him should not perish,
but have everlasting life. John 3:16
I also have one installed on my car. I don't have the EGR hooked up anymore due to running a P28 ECU, but I can vouch for the intake temps going down a good amount. My Hondata indicates that it went down a lot. I also do not have any coolant lines running to the intake manifold, so that helps even more. My IAC valve is external now, and I took off the coolant lines off my ITR TB, so my set-up is running very cold.
Originally posted by sun I also have one installed on my car. I don't have the EGR hooked up anymore due to running a P28 ECU, but I can vouch for the intake temps going down a good amount. My Hondata indicates that it went down a lot. I also do not have any coolant lines running to the intake manifold, so that helps even more. My IAC valve is external now, and I took off the coolant lines off my ITR TB, so my set-up is running very cold.
is the iac aftermarket, or factory that you have just relocated? pictures? was this all possible because of your ecm setup, or can this be successfully done running a factory p13?
vern
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vern - 93 jdm 2.3vtec 4ws
please say a prayer for isai perez jR, my godson 9.28.02-3.16.03
for God so loved the world that He gave His only begotten Son,
that whosever believeth in Him should not perish,
but have everlasting life. John 3:16
The IAC is a factory unit. I had to relocate it due to my Euro R intake manifold. See webpage in signature and go to the intake manifold "how to" page.
You could probably do it with a stock P13 ECU, but I have never tried it.
FYI: In order to install this spacer correctly, you need to remove all of the gasket material from the old intake manifold gasket. It does not come off easily like the S2000. It's a paper gasket that sticks to the head. It is a major pain in the butt to completely get it off. It's easiest to take out all of the studs off the head, and to use a gasket remover (liquid stuff).
Originally posted by sun FYI: In order to install this spacer correctly, you need to remove all of the gasket material from the old intake manifold gasket. It does not come off easily like the S2000. It's a paper gasket that sticks to the head. It is a major pain in the butt to completely get it off. It's easiest to take out all of the studs off the head, and to use a gasket remover (liquid stuff).
rotary drill with brass wire brush did the trick for me. dont use steel wire brush cause that will kill the mating surface. in the end my brass brush was completely killed. but small price to pay for the clean ass surface it left behind.
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vern - 93 jdm 2.3vtec 4ws
please say a prayer for isai perez jR, my godson 9.28.02-3.16.03
for God so loved the world that He gave His only begotten Son,
that whosever believeth in Him should not perish,
but have everlasting life. John 3:16
Originally posted by iranman What do you mean by the sensor not being "calibrated?"
I know of a chart in the Helm's manual showing a defined variation in IAT sensor resistance as a function of a change in specific air temperatures. If that doesn't show a calibration, then I must be confusing your definition of "calibration."
What I mean is that the Fluke pyrometers are produced and then the temp readings are probably adjusted by hand to give the best accuracy. I doubt that the IACs are produced this way (they are probably tested, though).
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Billy - 98 Prelude
#27 H2 NASA TX HondaChallenge
#27 PTB NASA TX Performance Touring Racing makes heroin addiction seem like a vague wish for something salty. -- Peter Egan
Holy Christ... look at what I started. I didn't know so many people would be interested. Maybe I should start reselling these things...
My tests:
The meter is a thermocouple meter, a little different than a true "pyrometer," though they do essentially the same thing. It's also a Tektronix, not a fluke. I don't distrust the stock IAT, but I wanted to be able to measure different things (external head, manifold temps, IAT, ambient) without worrying about any bias or error between measurement devices. I also didn't have an OBD scan setup working at the time (I had one, and was planning on using it) and started to worry about the refresh rate. With the meter I was able to see that when you stop, there's about a °/sec rise in head temperature. I might have seen that with an OBD setup, maybe not. Basically, I was more comfortable with the meter.
Prelude Heat Sources:
With the Prelude, there are 4 heat sources: EGR, TB coolant line, the IAC coolant line, and the head. If you look at these heat sources, the head is the largest (surface area) and it is "on" all the time. I still need to look at the EGR, but I believe it's only on during part-throttle cruising. It should shut off at idle and at WOT. This would be the second largest source (though exhaust gas temp may make up for quantity). The coolant lines are small, and have relatively low contact (surface) area. I believe the heating effect from them is minimal. The head is probably the biggest source, and without doing anything else (like EGR or coolant lines) I think the spacer/insulator would still be beneficial. How much? Don't know.
Coolant Line Bypassing:
I haven't tried it, but the IAC coolant bypass should be doable w/o any problems. The TB one is not as most people know (results in funky idle). I would be tempted to weld or plug the TB thermo valve holes to stop this, or someone with money could just buy an ITR TB (they swap).
Bypassing EGR:
The S2000 doesn't have it, so I didn't have to worry about it. On an OBD1 ECU, the EGR can be blocked and the computer won't care. On the OBD2 vehicles, there is a lift sensor and it WILL care (MIL). I'll look at the manual and see, but I think the EGR can be bypassed even on the newer ones, with some ECU trickery. I've got to look at the actuation system (vacuum or electronic?) and find a way to dummy the lift sensor so the ECU thinks it's working. Oh, and while the Hondata spacer DOES block the EGR, the hole can be drilled/cut out. I'll try and find a way around it, though.
Smog Testing:
Billy tells me the purpose of the EGR is to heat up the cat, not to "dilute" the emissions. I highly doubt removal will affect emissions. Besides, most places test idle and 2000-something RPMs. This will not affect idle, I have not yet seen a vehicle where the EGR opens at idle.
Calibration (since there seems to be some concern):
My Tektronix meter is calibrated at the factory. K-type thermocouples have very little variation from thermocouple to thermocouple. The meter is calibrated to work with them and that's it. You shouldn't have to worry swapping from one to another. I forget the variance, but it's pretty small (far less than what we have). I suspect the stock IAT to be a thermocouple as well, unless it's some solid state device. I remember it being 2-wire, though, not 3, which would tell me it's passive. Regardless, Honda's not going to tweak individual ECUs, so they must manage the variance in the IAT itself. I'm sure the variance is small, and even if not, what does it matter? What if the IAT is off a degree or two? For my tests, I wanted something *repeatable.* It was purely a practical reason, since I can't remove the IAT and measure the head temp or ambient very easily.
From what i understand, the EGR recirculates exhaust gasses into the intake manifold. From what I understand, doing so reduces combustion temps slightly because ther exhaust gasses will not combust as does the fuel/air mixture. Correct me if I'm wrong. Would bypassing the EGR cause enough extra heat to allow the engine to overheat? or come close? Just yesterday I was thinking about bypassing it...but was unsure of possible negative effects.
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Gone, but not forgotten...rest in peace Jon.
That's what the cooling system is for. While it might raise combustion temps slightly, guess what? You will be making more power. Our cooling system and engine can handle it, I wouldn't worry. Besides, you reduce the intake charge temp by probably as much as the EGR lowers combustion temp... I suspect in the end you are close to what you were anyhow. Too many people have run these without a problem.
A side note, Billy is about to drill and tap his theromostat housing to use an S2000 lower-temp fan switch I got him from Spoon. We'll write that up. That, coupled with a Mugen or Spoon thermostat will lower the engine operating temp to about 170°F, or about 25°F lower than stock. Not only will this certainly negate any "heating" effects due to bypassing the EGR, it will make more power by keeping the engine (and the intake charge temp) cooler. Will post full details when they are available...
Hey, anyone want to donate to NTPOG? We have been exceeding our bandwidth... you guys don't want to see us shut down, do you?!
