mattstryfe

This. You call it clearing the intake. If you do this, heat soak is slightly negligible. The cooler air your intake has access to; the better effect doing this will have. The manifold itself is what heats up the air as it moves through the plenum.

Here in Florida, especially in the summer, when temperatures are around 100 with the air being relatively stagnant and moist, it's hard for me to keep my intake temperatures below 120. Often, they are substantially higher. I am simply trying to illustrate that 'Clearing' the intake has an exponentially lowering effect on this as temperature rise.

Once you stop moving and the air in the engine bay becomes stagnant there is very little you can do. Vacating temperatures from the exhaust manifold can help. However, the main 'heat soak's source is the heat, via convection, from the engine itself. As I said above, once the intake manifold gets 'soaked' it takes a substantial amount of cooler (outside) air to bring it back down.

To test this out, download the torque app and get yourself a OBDII sensor. This is where you will see the magic happening.

You can reduce this through various techniques. I have listed some below.

• Hood vents
• Intake manifold spacer (Hondata)
• An intake that does not run infront or near the exhaust manifold
• Heat shield (between engine and intake piping/housing
• Moving to a cooler climate
• Never letting off the gas

The soak occurs with a stock intake box which points to the soak effect being less about the intake piping/housing and more about the intake manifold. This also points (significantly) to the Hondata spacer being the most effective way of reducing soak. Ironically, it also is rumored to be the huge pain in the ass to do. Removal of the intake manifold is a time intensive thing; but still possible.

I am in the process of putting together some of my logs to further illustrate the effects of different intakes, mods, and driving techniques and how they effect IATemps. Stay tuned!

Matt

*edit*
I am in now way saying that xviper's advice is bad. Quite the contrary. It's the best thing you can do that doesn't cost any time or money. I got in the habit of doing this after almost getting smashed by truck because of hesitation.

xviper

Matt, this whole business of "heat soak", hesitation, kangarooing, intake air temps, engine bay air temps is not new. Nearly 12 years ago, when this car was new, I did an exhaustive amount of experimentation and documentation on the subject. These findings were published here over 2 fairly lengthy threads. Unfortunately, the archives don't go back that far, so your contribution here will be most welcome and will be very useful in teaching (and reminding) those new and old to the S2000.
I am confident that your results will be consistent with mine from over a decade ago. The gist of those findings were that intake air temps can get very hot, very quickly when air flow is reduced. It doesn't take very long for it to climb but it can take an inordinate amount of time for it to come down and in most scenarios, it will never come back down as low as what it began. Engine bay temps can get up over 70*C in the summer and this is stifling for an engine. I did stock intakes, insulated stock intakes, CAIs, insulated CAIs, modified stock intakes, exhaust heat barriers, vented hoods, insulated radiators and a few other things I've long forgotten.
Along the way, the Hondata heat insulator came along and it proved to be a very useful mod for keeping intake air temps down, however, given the possible temps the engine bay can get up to, once the manifold reaches those lofty temps, the manifold simply gets heated and the Hondata piece does nothing. Like a beer cooler, it can keep cool things cool but it can also keep hot things hot.
Over the 13 years that I've owned this car, I've done almost every mod there is and have turned nearly every nut and bolt on the car. People come and people go from the S2000 ownership and many lessons learned from yesterday are long forgotten. In instances like this, it's time for some new blood to write new lessons.
Take the ball and run with it. Teach these new guys what they really need to know to understand and enjoy this car. I've run with the ball for so long, I just can't be bothered anymore. Besides, not many will listen anyway. They just gotta find out for themselves.

ronnuke

Yes heat soak does exist and does affect the drivability in traffic as said. I have experienced heat soak in mine as well. But don't discount the possibility that your TPS may have a bad spot in it like mine did. One good way to tell is if you have only just started driving the car for the day and it is not yet hot (although properly warmed up to normal operating temperature)and it still hesitates/bogs before surging ahead once you press the gas a little further. The new TPS (on the new throttle body) fixed my issue completely. I rarely experience heat soak anymore even here in Florida.

unclefester

You can't eliminate heatsoak - that's the what Xviper is getting at. If you have done the basic checks and the problem exists, that's usually because the problem is behind the wheel. I can get mine to trickle through traffic ( even on a hot day ) without touching the throttle pedal just by feathering the clutch very gently to get it moving. It will only 'bog' if you try and pull away with too few revs and are too sharp with the clutch.

But then all of that is already explained above.

Problems like stalling at junctions or when the engine simply dies are the result of things that need cleaning replacing. This was what mine was doing no matter how much i tried to drive around it.

Don't forget that on the OEM intake assembly, the inlet is right over the front of the radiator - this allows hot air to rise and be drawn directly into the inlet - never mind that the airbox and ram pipe are directly over the rear of the radiator - again a hot part of the bay. That is the reason why the intake air gets as warm as it does even on a cold day when you are stationary in traffic.

My 'cure' is to run the aircon all the time as the fan from that draws air through the radiator and away from the intake inlet area, I also find that the extra few rpm it adds to the tickover stops it bogging down as easily as the revs aren't floating down towards the 700s.

RobEvans

Thanks for the input guys its been a very informative read.

*edit I fitted my new MAP sensor today, my fuel trims are finally back to normal hovering around 0% instead of -12% also my car feels 100% better in traffic even with the intake temp at 60deg.

Im really happy now!

RobEvans

For the record my car is totally fixed now, after a few days driving in traffic my car is a dream to drive with no kangarooing in traffic at at!

I no longer hate driving my car to work and in WOT the car feels to have more grunt, i still believe it may heat soak in heavy traffic but at lease day to day driving is sorted now

Very happy s2000 owner and the love has come back! Thanks guys!

SpitfireS

Actually, the kangaroo hop is a very efficient way to get from A to B.
Energy is stored in the muscle during landing and is released on take-off, just a little bit extra is needed to keep moving.

That's why I always use the kangaroo-hop in my S2000 as much as possible.
It saves fuel!

s2000maniac