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Old 19-03-2014, 12:51 AM   #1
Samsara
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Car feels like it has lost power

I feel like my car has lost a bit of oomph lately, and I dont know what to put it down to. My first thought is the exhaust. It was previously fitted to a 2.0L that SwiftJimmy had (i think it was an FSZE). is it possible that the diameter is too large and thus reduced back pressure? Could that also be the reason behind the fartiness and raspyness of the exhaust?
I've checked the spark plugs and they're a ok... Coil packs/ignition leads is another thing that COULD be worth mentioning (I'm still a car noob), but apart from that, i have no bloody idea.

If you guys have thoughts on the matter, or think im crazy, i'd love to hear it.
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Old 19-03-2014, 05:48 AM   #2
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fuel filter (in tank), not sure on what diameter exhaust you have, and yes it was on a fs-ze, was the cat changed with the exhaust?
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Old 19-03-2014, 08:54 AM   #3
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check condition of air filter.

just cleaned mine yesterday. covered in black oil, leaves and bugs. also noticed loss of power and 10% increase in fuel usage recently.

feel better on throttle now.

also exhaust if too big could be causing issues under 3000rpm. but above that shouldn't be an issue.
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Old 19-03-2014, 10:15 AM   #4
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Originally Posted by Samsara View Post
I feel like my car has lost a bit of oomph lately, and I dont know what to put it down to. My first thought is the exhaust. It was previously fitted to a 2.0L that SwiftJimmy had (i think it was an FSZE). is it possible that the diameter is too large and thus reduced back pressure? Could that also be the reason behind the fartiness and raspyness of the exhaust?
I've checked the spark plugs and they're a ok... Coil packs/ignition leads is another thing that COULD be worth mentioning (I'm still a car noob), but apart from that, i have no bloody idea.

If you guys have thoughts on the matter, or think im crazy, i'd love to hear it.
While on the topic of back pressure, you havnt reduced back pressure. Back pressure is a term that refers to the resistance caused by obstructions or tight bends in a vessel along which the fluid is moving.

Given the exhaust is of the same design (in terms of bends etc) backpressure will be relatively the same.

What you've done is increased the diamater of the pipe and thus decreased velocity at low rpm which will result in a drop in low end performance. The trade off is that at higher rpm you can flow more volume at a lower velocity thus improving high rpm. Low velocities is what causes raspiness generally. When does the auto shift?

Could be multiple of things, you've gotten used to it. My car no longer feels fast for example. Otherwise Fuel, Cat, Fuel Filters, Air Filter might need replacing or cleaning etc. It takes about a tank for the stock ecu to adjust its maps for the increased octane.
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Old 19-03-2014, 02:13 PM   #5
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fuel filter (in tank), not sure on what diameter exhaust you have, and yes it was on a fs-ze, was the cat changed with the exhaust?
I used the Cat that was issued with the exhaust

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Originally Posted by project.r.racing View Post
check condition of air filter.

just cleaned mine yesterday. covered in black oil, leaves and bugs. also noticed loss of power and 10% increase in fuel usage recently.

feel better on throttle now.

also exhaust if too big could be causing issues under 3000rpm. but above that shouldn't be an issue.
I have the Simota CAI, and tbh I haven't checked the pod in 2-3 months after I cleaned it last... Should probably do that lol! Thanks

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While on the topic of back pressure, you havnt reduced back pressure. Back pressure is a term that refers to the resistance caused by obstructions or tight bends in a vessel along which the fluid is moving.

Given the exhaust is of the same design (in terms of bends etc) backpressure will be relatively the same.

What you've done is increased the diamater of the pipe and thus decreased velocity at low rpm which will result in a drop in low end performance. The trade off is that at higher rpm you can flow more volume at a lower velocity thus improving high rpm. Low velocities is what causes raspiness generally. When does the auto shift?
It depends, on normal driving, it shifts at the standard 20kmh/40kmh/60kmh, at around 2.5k - 3k (it avoids going on cam when it can), and the major raspy/fart happens at 2.6k.

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Could be multiple of things, you've gotten used to it. My car no longer feels fast for example. Otherwise Fuel, Cat, Fuel Filters, Air Filter might need replacing or cleaning etc. It takes about a tank for the stock ecu to adjust its maps for the increased octane.
Okay cool.

Thanks guys, I'll check the fuel filter as well
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Old 19-03-2014, 04:09 PM   #6
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Yeah my car rasps around that territory too IIRC. (Kinda hard to tell with no gauge displaying revs to tell specifically)
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Old 20-03-2014, 10:58 AM   #7
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Exhaust leak?
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Old 20-03-2014, 11:35 AM   #8
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is this happened after we put the coilovers in??? might be the toe causing more drag on the car... or the cat in the muffler getting poo. or the air filter (pod filter) getting blocked.. id do a full service (oil, air filter, fuel filter) can do it at my house one arvo if u like
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Old 20-03-2014, 12:04 PM   #9
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Exhaust leak?
Mat keeps suggesting this, but ive had a look under the car all away along the exhaust system and cant see any black residue. The only other option is that theres a crack underneath the exhaust manifold


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is this happened after we put the coilovers in??? might be the toe causing more drag on the car... or the cat in the muffler getting poo. or the air filter (pod filter) getting blocked.. id do a full service (oil, air filter, fuel filter) can do it at my house one arvo if u like
I've had a wheel alignment since the coilovers went in, the toe has been fixed properly (it was out by a metric **** tonne). I changed the oil and filter over 1500kms ago... will have to check out the other two tomorrow when I dont have work
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Old 20-03-2014, 12:18 PM   #10
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Clean the pod man, it'll make the world of difference!
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Old 20-03-2014, 02:33 PM   #11
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How long since the car has been serviced.
Cover off the normal wear and tear items first. Reminds me of...
http://www.youtube.com/watch?v=qa77k25g6wQ
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Old 20-03-2014, 04:05 PM   #12
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even though plugs look ok they may still be stuffed so don't turn a blind eye to that
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Old 20-03-2014, 10:32 PM   #13
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Its more likely air restriction then anything else (if the cars runs okay but has just lost power), get a new air filter or clean the one you have, also if its been a while change the plugs, (only cost you $20 for a new set), I doubt its the coil pack (think you would notice other things besides the power loss), I just did the plugs, new pod, engine oil and filter and it cost me about $130 that's nothing for piece of mind.
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Old 20-03-2014, 11:26 PM   #14
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also clean your afm sensor
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Old 21-03-2014, 09:21 PM   #15
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Nothing intersting happens until you hit 4k rpm :P
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Old 23-03-2014, 01:51 AM   #16
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How long since the car has been serviced.
Cover off the normal wear and tear items first. Reminds me of...
http://www.youtube.com/watch?v=qa77k25g6wQ
I perform an Oil and Filter change every 5,000kms, a visual spark plug check, the usual coolant, brake fluid, PS fluid, brake pads etc. they're visual checks and i havent had to act on them just yet. I prefer avoiding mechanics as the car comes back worse than when I take it in. (I think they unbolt ****/wear **** on purpose, so i keep dropping money on them).

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even though plugs look ok they may still be stuffed so don't turn a blind eye to that
Anything else visually i need to look out for when inspecting plugs? Apart from the oil and burn marks whch are obvious.

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also clean your afm sensor
You mean maf? I give that a clean with a bit of water on a rag lol.
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Old 24-03-2014, 12:51 PM   #17
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Nothing intersting happens until you hit 4k rpm :P
In the absense of a like button. *Like*

Quote:
Originally Posted by Samsara View Post
I perform an Oil and Filter change every 5,000kms, a visual spark plug check, the usual coolant, brake fluid, PS fluid, brake pads etc. they're visual checks and i havent had to act on them just yet. I prefer avoiding mechanics as the car comes back worse than when I take it in. (I think they unbolt ****/wear **** on purpose, so i keep dropping money on them).


Anything else visually i need to look out for when inspecting plugs? Apart from the oil and burn marks whch are obvious.


You mean maf? I give that a clean with a bit of water on a rag lol.
Use some contact cleaner on the connection, unplug replug wiggle etc.

Id use degreaser or contact cleaner on the wire as the main culprit is oil from the filter causes **** to stick to the element.
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Old 14-04-2014, 08:52 PM   #18
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It could be anything, but more info would help.

Did it happen right after you changed the exh, or did it happen one day out of the blue without touching anything.


PS That Ice88 has his sh!t together, he knows how exh works.

Last edited by Old Grey; 15-04-2014 at 06:11 AM.
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Old 14-04-2014, 10:19 PM   #19
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Sam if you go to super cheap or repco either one and get a can on AFM or MAF there the same thing. But the MAF sensor cleaner by CRC. And the pull the MAF off and give it a really good spray with that ****.

Also get some throttle body cleaner and give the throttle body a clean. And while your at it also get a can of the nulon upper engine cleaner and give it a hit with that.

But defiantly change you fuel filter if you haven't done so yet.
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