intake cooling

[Coupe-R]

The factory ecu starts retarding about 3 degrees of timing at about 37C intake temp and it just retards up to 5 degrees or more at 60C

Also colder air has more oxygen content, so colder is better yes

[b18c1]

Originally Posted by Coupe-R

The factory ecu starts retarding about 3 degrees of timing at about 37C intake temp and it just retards up to 5 degrees or more at 60C

so say if you do get lower temps etc would you reconmend a re-tune to adjust retarding and a cooler intake?

[Coupe-R]

no not at all

thats what the electronic ECU in the car is for, to compensate for things like that.

at 25C there is no ignition retard, also more fuel as it gets colder too.

We ain't in carby land

[b18c1]

Mint!

[enigami]

Originally Posted by b18c1

so say if you do get lower temps etc would you reconmend a re-tune to adjust retarding and a cooler intake?

Hey, how far does the pm7 ecu in terms of correction alter the a/f ratio once tb is bypassed and iacv? Im curious to know if the changes made by the ecu without a tune returns the output (after bypassing etc) to near factory spec (not using IACV vs using IACV) ?

I know its beneficial temp wise but am curious about tuning -> can a tune be used here? as on my 89 ef3 i bypassed only tb and it idled/ran fine, Though recently ive bypassed tb/iacv/Heater core and have a steady idle but powerwise feels very similar at meremere (JTune Drags) etc although at nightdrags ive noticed acc more rapid with tb and iacv than nitedrags with tb bypass only.

I hope this makes sense
Thank you

[Coupe-R]

Didn't read your post too closely,
however the IAT is the sensor that corrects air temp/fuel

its usually bolted to a runner on the intake manifold.

The IACV is just that Idle air control valve - for idle stability.

IAT=Intake air temp sensor

two completly different things

[Deanis]

Originally Posted by Coupe-R

The factory ecu starts retarding about 3 degrees of timing at about 37C intake temp and it just retards up to 5 degrees or more at 60C

interesting. i reckon ive seen this timing retard at the drags on hot days.

i used to keep a good eye on temps, using a multimeter with a temp probe. i noticed power (trapspeed) would stay fairly constant up until 25 degrees where the power would start dropping off. 25 under the trees at meremere probably roughly 37 at the intake sensor by the time it heats up through the intake. it seemed random that once you hit 25 degrees you would instantly loose about 2kph trap. makes sence now though.

[Coupe-R]

interesting. i reckon ive seen this timing retard at the drags on hot days.

yes I had this BADLY in my old DA6 once, it actually made me loose 1st place in the 14.7 second bracket years ago.

You know you can take the timing retard away if you want deanis, its just a safe gard incase it knocks (doubt it will unless you have MEGA timing and compression and bad gas)

another reason why to do a burnout, it will actually cool the intake a little bit by having a wide open throttle.

P.S the intake will usually be above 25C at the drags from heat soak, ESPECIALLY in the summer it would see 38-60C on some hondas!

[bumpd-EG]

sorry to be a knob but can someone draw up a little shitty mock up of how to do this?

[Coupe-R]

huh?

to do what?

The post was about intake gaskets stopping as much heat soak to the intake manifold.

The IAT retard I am talking about, adjusting that you need a chipped or aftermarket ecu.

Or you could buy one of those "MEAN AU" resistors off trademe so the car will always be at a fixed IAT temp.
(Don't do this) It will make fuel as well as timing wrong under super cold/hot conditions.

[bumpd-EG]

nah how to bypass all this coolent shit n so on?
I know it sounds silly but I have never tried it, is it worth doing it to my itr?

[Pommy]

word above, id like to do it too but havent got a clue which pipe to yank off, heard it messes up the cold idle but id rather have a little more power!

[Coupe-R]

Ok there is different throttle body and IACV depending on what car is it.

I.E EG6 civic has a FITV on the throttle body, so removing the coolant lines to it can screw up the cold idle.

ITR doesn't have a FITV on the TB, BUT it still has coolant lines running through it to stop the throttle plate sticking in cold weather.

You can remove the random two lines going into the TB on a Type R OBD2 Throttle Body. It won't have any ill effects at all, unless the throttle plate freezes

I have never removed the two coolant lines from the IACV at the back of the inlet manifold. Either these lines serve a purpose (moving a wax plunger) (doubt it tho cause it's electronically controlled) or they just stop the IACV freezing. (unsure)

There is also a BIG water pipe running through the inlet manifold that if you get another inlet mani gasket and block the port off you can re route the water around the inlet manifold.

[Pommy]

shit i dont have a clue what pipe is what, on an h22a theres a pipe that i think is the one your talking about off the tb but theres heaps onto the IM... ill try to find a pic of an h22a IM so maybe you could cirle what to remove?

[Coupe-R]

If your H22A is OBD1 in which case removing the throttle body water pipes MAY cause a poor cold idle. (maybe people remove the FITV and make a block off plate, or get a OBD2 throttle body)

I have no idea what removing the water pipes from the IAC valve would do (maybe nothing)

[AzN_K]

How to - Lyonel's Garage