No low end power??

[TurboFreak]

What do you think could be causing a 7MGE to have low end power issues. Not bogging down but just feels down on power. The car is completely driveable and I haven't ever driven a 7MGE before this one so I can't compare it to anything. The car runs strong in the higher gears like there is nothing wrong.

Only things that are "wrong" is that there is a pretty substantial exhaust leak from the header to the downpipe where the two are a little separated and is missing an exhaust gasket.

My thoughts on the cause of the issue are:
-Timing
-The exhaust leak
-Spark Plugs(Maybe, doubt it though)
-Low Compression:cry:

 

[DonS1mpson]

It's an NA? :dunno:

 

[Ma70.Ent]

It's an NA? :dunno:

Don't post stuff like this.

 

[Ma70.Ent]

What do you think could be causing a 7MGE to have low end power issues. Not bogging down but just feels down on power. The car is completely driveable and I haven't ever driven a 7MGE before this one so I can't compare it to anything. The car runs strong in the higher gears like there is nothing wrong.

Only things that are "wrong" is that there is a pretty substantial exhaust leak from the header to the downpipe where the two are a little separated and is missing an exhaust gasket.

My thoughts on the cause of the issue are:
-Timing
-The exhaust leak
-Spark Plugs(Maybe, doubt it though)
-Low Compression:cry:

Yeah, those all could effect it, but the ACIS not working could be a reason too, unless you know for a fact it IS working.

 

[AJ'S 88NA]

All the above. What is your timing set at? Try +14deg. It will help out the bottom end response. Check out your compression to see were your at.
The ACIS if it is stuck will affect the low end also like MA 70 said, there is a cover on the intake you can take off to check it and see if it needs cleaned and is freely operating.

BTW MA 70, I agree with the sticky about the NA jokes, they are getting old and serve no purpose or help.

 

[Ma70.Ent]

All the above. What is your timing set at? Try +14deg. It will help out the bottom end response. Check out your compression to see were your at.
The ACIS if it is stuck will affect the low end also like MA 70 said, there is a cover on the intake you can take off to check it and see if it needs cleaned and is freely operating.

BTW MA 70, I agree with the sticky about the NA jokes, they are getting old and serve no purpose or help.

Thank you for agreeing.

Anyways, if you want to know about ACIS, it's in the sticky thread. It tells you how it works and stuff

Also, if you set your timing to 14 BTDC, you'll need to run higher octane gas.

 

[iwannadie]

You need back pressure for low end power Ive always thought. If your leak is maybe bigger than you think you could be loosing the power there.

 

[thechori]

The car runs strong in the higher gears like there is nothing wrong.

so is it only in 1st gear?

 

[iwannadie]

I know when I got my exhaust it seemed to be too free flowing and I lost low end power off the line. Top end power seemed better, I put a silencer in to restrict a little bit. The low end power came right back.

If you know theres an exhaust leak fix it, it might solve the problem it might not but at least its fixed lol.

 

[Ma70.Ent]

I know when I got my exhaust it seemed to be too free flowing and I lost low end power off the line. Top end power seemed better, I put a silencer in to restrict a little bit. The low end power came right back.

If you know theres an exhaust leak fix it, it might solve the problem it might not but at least its fixed lol.

When I posted, I pointed that the exhaust leak would cause it to be too free flowing. lol...

 

[TurboFreak]

Good, these are the responses I wanted. I bought the car but I'm not picking it up until this coming week sometime, so I can't really check anything until then.(I did test drive it before buying) I just wanted to get some preliminary thoughts about how to diagnose it and now I have them

MA70, Iwannadie, etc. - the exhaust leak is pretty substantial, I think. When i put my hand up to the place that is leaking I can feel the exhaust escaping and I can also see white all around the area.

DonCarStealer - N/A jokes are gay and worthless.

Chori -"Power loss" is in the first couple gears. She runs perfect on the highway.

Thanks!

 

[7M-fanatic]

First off, do you have it tied to an automatic trans?

Second........
Jeese I get tired of this 'you need back pressure' BS !
If, when someone puts on a free flowing exhaust, and they loose power,
it is because their car is running lean !

The stock ECU supplies only enough fuel to burn with what ever exhaust residue is left in the cylinder with the stock high restriction exhaust system.

If you un-cork the exhaust, you lessen the amount of exhaust polluting the already lean incoming charge, and makes it even leaner.

Typically, the people saying that you need back pressure, have never used an A/F meter, and have no idea how much a free flowing exhaust cuts down on the CO contamination of the incoming fresh charge, thus causing a super-lean mixture.

So open up the exhaust, add a S-AFC to dial more fuel in,
and make some real HP !!

Now, if you have an automatic, part of the lack of bottom end is caused by the ECU.
I have tricks to fix the off-the-line blues caused by the ECU on automatic equipped NA 7Ms.

 

[TurboFreak]

Nope 5-speed

 

[amichie]

Just a dsicussion point below.

I read in a book once that if exhaust manifold velocity is too low then exhaust reversion can occur during the valve overlap period. i.e. the exhaust gas inertia is so low that the exhaust can be sucked back in at low rpm diluting the charge. This seems to fit with that very common experience of lost botom end after fitting a bigger exhaust system.

The book also suggested that a mismatch between the exhaust manifold diameter and the exhaust port diamater will help in this case. i.e. bigger hole in the manifold than in the port.

 

[Ma70.Ent]

First off, do you have it tied to an automatic trans?

Second........
Jeese I get tired of this 'you need back pressure' BS !
If, when someone puts on a free flowing exhaust, and they loose power,
it is because their car is running lean !

The stock ECU supplies only enough fuel to burn with what ever exhaust residue is left in the cylinder with the stock high restriction exhaust system.

If you un-cork the exhaust, you lessen the amount of exhaust polluting the already lean incoming charge, and makes it even leaner.

Typically, the people saying that you need back pressure, have never used an A/F meter, and have no idea how much a free flowing exhaust cuts down on the CO contamination of the incoming fresh charge, thus causing a super-lean mixture.

So open up the exhaust, add a S-AFC to dial more fuel in,
and make some real HP !!

Now, if you have an automatic, part of the lack of bottom end is caused by the ECU.
I have tricks to fix the off-the-line blues caused by the ECU on automatic equipped NA 7Ms.

That's some useful info right there

 

[novaboy009]

I want tricks for my auto ECU!!!!

Kev

 

[iwannadie]

First off, do you have it tied to an automatic trans?

Second........
Jeese I get tired of this 'you need back pressure' BS !
If, when someone puts on a free flowing exhaust, and they loose power,
it is because their car is running lean !

The stock ECU supplies only enough fuel to burn with what ever exhaust residue is left in the cylinder with the stock high restriction exhaust system.

If you un-cork the exhaust, you lessen the amount of exhaust polluting the already lean incoming charge, and makes it even leaner.

Typically, the people saying that you need back pressure, have never used an A/F meter, and have no idea how much a free flowing exhaust cuts down on the CO contamination of the incoming fresh charge, thus causing a super-lean mixture.

So open up the exhaust, add a S-AFC to dial more fuel in,
and make some real HP !!

Now, if you have an automatic, part of the lack of bottom end is caused by the ECU.
I have tricks to fix the off-the-line blues caused by the ECU on automatic equipped NA 7Ms.

Theres so many threads about free flowing exhaust robbing power or not, I wont go into it. From my understanding though you dont Need pressure but you need velocity. The easiest way to get exhaust velocity is back pressure, you find the balance of free flowing enough without being too restrictive. Ive never seen any na vehicle make gains from an open exhaust, only turbos.

Then again, I admit freely Im no expert, just repeating what Ive seen/read.

 

[7M-fanatic]

Yup, that BS is all over the 'net.
It's from people not understanding the whole picture,
and getting theory in the way of actually tuning a car.
You don't see exhaust restrictors on F1 cars......
Try tuning a NA engine once the free flowing exhaust has been installed......

 

[TRG22]

Now, if you have an automatic, part of the lack of bottom end is caused by the ECU.
I have tricks to fix the off-the-line blues caused by the ECU on automatic equipped NA 7Ms.

I have an auto NA and would love any info you could give regarding the above...

 

[87mgte]

It's an NA? :dunno:

lol there's a sticky thread about these kinda comments in this section. i literally just read it 30 seconds ago.