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Discussion Starter · #1 ·
Hey all,

Been trying to figure out the next mod for my ms3. I have the cobb sri and and that is it.

A tbe or at least a dp sounds like good bang for the buck, but the hit and miss nature of the smoking is turning me off. So I've pretty much focused my attention to the ap - especially now that people seem happy with the 1.03 maps.

However, I have a couple questions/concerns.

I am at an altitude of about 3500ft. I've read in here that at altitude the ms3's ability to hold boost diminishes - which is consistent with what I am seeing ( hold about 13psi or so). So the first question that comes to mind is:

1. If I don't even hold stock boost levels, is the AP going to help me out? Will I hold higher boost levels with the AP?

I'd really love to hear from some people using the 1.03 maps at 3500 feet or greater - do you notice a difference? What boost are you holding?

2. There is another active thread right now about the AP Stage 1 Maps - there seems to be a couple of people (at least I think it is just a couple) with some issue of part throttle over boost where acceleration at part throttle is jerky. I presume most people with the 1.03 maps are NOT experiencing this?

3. those running ap 1.03, with cobb sri and 91 octane, would love to hear overall impressions - really curious if there is anyone out there running this combo and not experiencing any issues.

I'm in Canada and the cost of getting the ap after exchange (knew I should have bought if 4 or 5 months ago when our dollar was basically par. :( ) and shipping and brokerage, gets pretty pricey; I really don't want to be stuck with something that is going to give me more headaches than driving enjoyment.

Thanks a lot!
 

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i would do other basic bolt ons before I would do an AP. but if anything you would think running at higher altitude will make the car even more stable (just slightly less powerful).
 

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Your car will hold more boost...and gain power.

You just won't have as much power as a car at sea level...cuz density altitude is higher at your location.
 

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I would personally wait due to your ALT. I think most of the maps were done close to sea level. 3500 might be pushing it. I really don't think I would risk it and go with other basic bolt-on's or if you must have tuning, go with a SB.
 

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the ECU will tune itself to the density altitude. You won't have a problem.

I guarentee you on a very hot humid day at close to sea level...the density altitude can get to above 3,000 ft. so its not gonna matter.
 

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by the way the standback has problems controlling boost at altitude from what I have heard so that would not be the best option
 

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Discussion Starter · #9 ·
What other bolt on's would you guys suggest? DP seems to be the most popular one, but like I said initally, not sure I want to risk starting to smoke - or does this only happen infrequently?

I also like the idea that with the AP I can flash back to stock if I need warranty work.
 

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Discussion Starter · #10 ·
[quote author=blam link=topic=135731.msg2923681#msg2923681 date=1234200069]
Anal Perversion?
[/quote]

Access Port.
 

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[quote author=dread link=topic=135731.msg2923683#msg2923683 date=1234200119]
by the way the standback has problems controlling boost at altitude from what I have heard so that would not be the best option
[/quote]

Dread, what did you hear exactly? As far as I'm aware, the Standback doesn't care what the altitude is. The turbo does on the other hand as it'll be harder to hit the same boost target as a car at sea level.

Here's a datalog from a customer of ours in Colorado. He contacted me and asked if I could help him tweak his PID parameters for high altitude duty, and we were able to eek out a few more pounds of boost by redline, and without any considerable spiking. So far as I know, the SB had no problem controlling boost:



That's at 5000ft elevation, so I think the OP will be just fine at 3500ft. Dread, maybe you can elaborate about the problems you hear we're having? :cheers:
 

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Turbo's were invented for jets to maintain engine power at high altitudes. The altitude will affect your car very little if at all compared to a N/A car. Certainly not enough to affect a buying decision.
 

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Discussion Starter · #15 ·
[quote author=Wheelhouse link=topic=135731.msg2924351#msg2924351 date=1234214153]
Turbo's were invented for jets to maintain engine power at high altitudes. The altitude will affect your car very little if at all compared to a N/A car. Certainly not enough to affect a buying decision.
[/quote]

I appreciate that turbo's are less affected by altitude then N/A.

My concern\question was that if the ms3 doesn't (can't?) hold the factory rated ~15psi at altitude, will increasing the boost (as I believe the ap does) cause the boost level that is held to increase? Or is there some limitation at altitude that prevents holding boost over a certain level (say the 13psi I currently see)?
 

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[quote author=dread link=topic=135731.msg2923683#msg2923683 date=1234200119]
by the way the standback has problems controlling boost at altitude from what I have heard so that would not be the best option
[/quote]

i wish SMF had that groan button like other forums have... LOL
 

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[quote author=pheare link=topic=135731.msg2924364#msg2924364 date=1234214707]
[quote author=Wheelhouse link=topic=135731.msg2924351#msg2924351 date=1234214153]
Turbo's were invented for jets to maintain engine power at high altitudes. The altitude will affect your car very little if at all compared to a N/A car. Certainly not enough to affect a buying decision.
[/quote]

I appreciate that turbo's are less affected by altitude then N/A.

My concern\question was that if the ms3 doesn't (can't?) hold the factory rated ~15psi at altitude, will increasing the boost (as I believe the ap does) cause the boost level that is held to increase? Or is there some limitation at altitude that prevents holding boost over a certain level (say the 13psi I currently see)?
[/quote]

even @ lower altitudes they don't really hold the 15psi. there is no reason why @ higher altitudes it wont be able to hold the same PSI, the power loss comes in the atmospheric pressure. Stock compression is 9.5:1 based on 1 BAR atmospheric pressure. Stock boost lets say for sake of arguement is 1 bar (14.5psi). @ sea level its like your total compression is 19:1. @ 3500 ft 1 bar is roughly 13PSI which means the car basically runs like it has a static compression ratio of 8.5:1, your turbo will still be creating the same boost it was before but now its like your total compression ratio is 17:1.
 

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[quote author=Wheelhouse link=topic=135731.msg2924351#msg2924351 date=1234214153]
Turbo's were invented for jets to maintain engine power at high altitudes. The altitude will affect your car very little if at all compared to a N/A car. Certainly not enough to affect a buying decision.


[/quote]

Not for jets...for piston driven aircraft lol...

But I do give you props for at least knowing this...not many people do.





Turbos were built so they can feed the same amount of air into the engine no matter what the altitude. Now that doesnt mean turbos will continue to work no matter how high you go....even turboed aircraft have a critical altitude in which the turbo will not be able to keep up and you will slowly start to drop manifold pressure 1 inch per thousand feet.

Now the question is how efficient are our turbos? If we push the turbo to the limit (we have constantly been pushing more and more PSI out of our turbo...so who relaly knows what the limit is) at sea level...then we will definatly loose PSI as we increase altitude.

But if the turbo still has more juice in it...you can potentially increase altitude and hold the same PSI the entire way. For example, if we tuned our turbo to 5 psi...you could easily go from sealevel all the way to 5,000 ft. and youd still have 5 psi. But if we turn it to 20...and the limit of the turbo is 20...you will loose PSI as you increase alititude.

But all that is beside the point, the poster is asking if you use a tune for "sealevel" will it hurt the car and will it increase performance.

It will not hurt the car, and you will have better performance then if you car was untuned. The ECU will adjust to the density altitude, tune or not. Will it perform as well as a car that is tuned at sealevel? Possibly not...but it WILL be better then a untuned car at your altitude.
 

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I was merely reporting the result of a user on the mazdaspeed forum who claimed he was in contact with cpe and they were unable to resolve the issue which he said was related to altitude. I'm not trying to start a flame war here, so I apologize if the statement was incorrect. If the standback works at altitude thats great, so does the AP. So it doesn't matter which solution he decides to go for.
 
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