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-   -   Daft question - Can the weather affect your max boost? (https://www.scoobynet.com/general-technical-10/424058-daft-question-can-the-weather-affect-your-max-boost.html)

Playsatan 03 May 2005 08:43 AM

Daft question - Can the weather affect your max boost?
 
Normally don't take my car out in the rain (wuss, I know) as it's a weekend motor. However, I had it out on Sunday for a 1/4 mile day at Crail and noticed something odd.

The car always feels rocket ship fast as my daily drive is a 1.6 focus but this time it felt a little tamer, I also noticed that instead of hitting a peak boost of 1.5bar the highest I could get it was 1.35. The thing is it was absolutely pouring, monsoon style, and I wondered if this can have an effect on the boost.

I know cool air has more oxygen by volume and that the intercooler would have been soaked but could this account for the loss of boost? Or is this the daftest question in a while?

andydavies 03 May 2005 09:11 AM


Originally Posted by Playsatan
Normally don't take my car out in the rain (wuss, I know) as it's a weekend motor. However, I had it out on Sunday for a 1/4 mile day at Crail and noticed something odd.

The car always feels rocket ship fast as my daily drive is a 1.6 focus but this time it felt a little tamer, I also noticed that instead of hitting a peak boost of 1.5bar the highest I could get it was 1.35. The thing is it was absolutely pouring, monsoon style, and I wondered if this can have an effect on the boost.

I know cool air has more oxygen by volume and that the intercooler would have been soaked but could this account for the loss of boost? Or is this the daftest question in a while?

Temperature will effect power as you say as the air cools its density increases thus for any given volume the oxygen content will increase. However I would expect to get more boost when cooler and not to achieve full boost when its a hot sunny day, which is reverse of what you describe.
Andy.

Cret 05 May 2005 10:52 PM

Ditto - I was driving mine the other day in cold misty air and there honestly seemed to be a noticeable difference in the amount of va va voom on tap. It does seem to like the colder/damper conditions.

Not sure what would cause it to behave the opposite way though!

Roojai 06 May 2005 12:08 AM


Originally Posted by Cret
It does seem to like the colder/damper conditions.

Not sure what would cause it to behave the opposite way though!

Dry and hot?

Cret 06 May 2005 12:54 AM


Originally Posted by Roojai
Dry and hot?

Hmmm, let me see.....


Originally Posted by Playsatan
The thing is it was absolutely pouring, monsoon style,

No, guess not.

Playsatan 06 May 2005 08:15 AM

Think I'll have to get my hands dirty and start checking over all the hoses, i/c, actuator etc. Just wanted to see if anyone else had seen similar problems.

Guess that'll teach me to get the car out more often and not be such a nancy boy with it. DCCD and no abs take a bit of getting used to in the wet though.

Triple X 06 May 2005 11:22 AM

Your filter isnt open to the elements is it (mini scoop)? Possibly getting a soaking, effecting induction MAF etc...

Playsatan 06 May 2005 01:14 PM


Originally Posted by Triple X
Your filter isnt open to the elements is it (mini scoop)? Possibly getting a soaking, effecting induction MAF etc...

Nah mate, standard airbox with a panel filter. Although.......... I do have the blanking plates on the bonnet vents removed. Could this be the problem?

Triple X 06 May 2005 01:43 PM

Shouldnt be a problem really, many a people give their engine bay a good soaking with water when cleaning.

Hows the boost been since?

Playsatan 06 May 2005 02:12 PM

Good question. Think I'll take it out tonight for a test before I start to take it apart.

Playsatan 06 May 2005 09:07 PM

Nope, still the same. Took it for a blast tonight and could only manage a feeble 1.32 max boost. Looks like it spanner time.

Hoppy 07 May 2005 03:31 AM

Induction temperature has a big effect on boost and power, and so does atmospheric pressure.

Worst case is warm/hot day plus thunderstorm, best is brass-monkey winter day with blue sky and frost. Also, heat-soak to the IC in slow traffic, stopped at junction etc can send inlet temps soaring in seconds, killing power and also promoting dangerous det :eek: Was that the situation with you?

I'd put the blanking plates back on the bonnet and first thing I'd check is that the air filter isn't sodden. Also, 1.5 bar of boost is very high and may, I suspect, be part of the problem. What mods have you got?

I'll exit now, so that those with real knowledge can comment. Despite the weather, I suspect there's summat wrong :(

Richard.

Playsatan 08 May 2005 01:16 AM

Mod wise its pretty stock, H&s decat, blitz nur spec, walbro pump. fse fpr, sti panel filter, apexi pfc. Think thats about it for the mo.

As for det the pfc never went above 14 and the k/link never went above the 2nd green on max setting so no worries there. But, I think I've got is sussed.

I recently had the i/c off to access a loose earthing strap on the starter motor and think I may have over tightened one of the jubilee clips on the boost hoses afterwards and stripped it a little. Had the whole lot out today and replaced it, took it for a spin and the result was 1.45. Not quite back to where I was but bloody close. Will fiddle a bit more and see if I can find the last little bit.

As for 1.5 being too much, wait till I get a hybrid turbo, fmic and some new injectors. Hoping to push way more.

sti-spec-a 08 May 2005 08:06 AM

Also sitting in the queue for to launch it up the strip would heatsoak the intercooler. The induction charge would not stop dropping till you are halfway up the strip

1.5 is not vey high and is perfectly safe with AndyF writing the map.

Grant


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