ZHP with straight pipes.....HELP!!!

[perpoy]

I put a REMUS muffler and remove both of my resonator to make it a bit louder....LOVE the end results BUTTTT...........I start my car and the RPM stays in 7.5-1k on idle.I go for 1st gear the RPM goes 3k pretty quick....then 2nd gear 3k on 20-25 mph and i don't feel any power.Had more acceleration power when I still have my big resonator on.
My gas mileage also decreased.Are these normal?.....Will this VOID :banghead: my warranty if something goes wrong with the engine or the transmission?Please guys....need your input.

[aggieE46]

I think something else got screwed up. Putting on an exhaust shouldn't do anything. And no, a cat-back will not void your warranty.

[Devonjordan]

It may have reduced low end torque because you removed some of the exhaust backpressure.

[bimmer07]

you have less backpressure. I think most people leave the first resonator in.

[ritos530i]

When doing this sometimes the O2 sensor goes bad.
Have them checked. And I only remove the muffler and last resonator. If you removed cats and did not add the O2 sensors in a tubing this will cause major issues. Put the O2s in your pipe if you removed them.

[330i ZHP]

Less backpressure - less torque...but more flow at high rpm...

Your setup is a bad idea for street driven car.

[ritos530i]

Less backpressure - less torque...but more flow at high rpm...
This is far from being true.

Your setup is a bad idea for street driven car.
I can tell you that you have no idea about my setup.
And my results are what i want them to be. Get the TS kit and lets find out who car is making more power. I will be waiting on your finished product.
No disrepect lets just see.

[EIAlfonso]

I can tell you that you have no idea about my setup.
And my results are what i want them to be. Get the TS kit and lets find out who car is making more power. I will be waiting on your finished product.
No disrepect lets just see.

I think he's talking to the original poster.

[330i ZHP]

I can tell you that you have no idea about my setup.
And my results are what i want them to be. Get the TS kit and lets find out who car is making more power. I will be waiting on your finished product.
No disrepect lets just see.

I was not talking to you at all. And your setup is wicked cool, but I learned my lessons years ago (I am 39) with nitrous. Your car will be much quicker than mine, but lets keep making runs into your bottle(s) run out...and lets see who wins then. I have had the unhappiness of an empty bottle.

But hey, I was talking to the OP. He wanted to know why his car felt less powerful.

I have made drag cars and used the straight exhaust method (hell, I have done open headers before)...for high RPM power, less back pressure is key.

I hope you understand and that there isnt any bad blood.

Stuart

[2000_328CI]

Less backpressure - less torque...but more flow at high rpm...

Your setup is a bad idea for street driven car.
+999

[330i ZHP]

hey chase, havent seen you around much lately...staying out of the mar?

[DarXide]

Less backpressure - less torque...but more flow at high rpm...

Your setup is a bad idea for street driven car.

:werd:

I noticed this when I went from my Rogue DMS to a custom quad running both resonators and no muffler..
Car pulls more on the low end..
Also the diameter of the piping makes a difference. When the piping is bigger you'll feel that is slower on the low end but faster on the high end..

[ritos530i]

Good point to raise. If you changed the diameter of the piping above 3 inches any where in your setup or 2.5 inches you will have loss of power low end.

330i ZHP, sorry for the misconfusion on my part. However i would be willing to race you off the bottle without the nitrous and you on the TS kit. I see we are both about the same age so our past experiences will definately play a big role in what we have done and where we are at now.
By the way you car is nice and I can tell you that you will be satified with the TS kit without a thought. I wish someone did my car with the TS kit but i had to find other means to bhp.

Also i can tell you that I am in no competition with 3 series and i just want to have the badest 530i for what it is and nothing more. i came make my car a 1000bhp if i want to but that wasn't the goal.

Back to OP problem. He has one of two issues. O2 doesn't like what he did and went bad or his exhaust has leaks somewhere or compression is lost.
A leak down test will tell him where his loss of pressure is at and One of the four O2s went south(bad) which is common on these type setups for BMWs.

[perpoy]

Thank's for the response guys.....How will I solve this problem though?I really love how it sounds now...?

[330i ZHP]

Good point to raise. If you changed the diameter of the piping above 3 inches any where in your setup or 2.5 inches you will have loss of power low end.

330i ZHP, sorry for the misconfusion on my part. However i would be willing to race you off the bottle without the nitrous and you on the TS kit. I see we are both about the same age so our past experiences will definately play a big role in what we have done and where we are at now.
By the way you car is nice and I can tell you that you will be satified with the TS kit without a thought. I wish someone did my car with the TS kit but i had to find other means to bhp.

Also i can tell you that I am in no competition with 3 series and i just want to have the badest 530i for what it is and nothing more. i came make my car a 1000bhp if i want to but that wasn't the goal.

Back to OP problem. He has one of two issues. O2 doesn't like what he did and went bad or his exhaust has leaks somewhere or compression is lost.
A leak down test will tell him where his loss of pressure is at and One of the four O2s went south(bad) which is common on these type setups for BMWs.

What have you done to your car other than the wild nitrous setup? You can PM me with details if you want...how much power are you putting down? I am curious. I want to make my car damn quick without sacrificing any reliability.

[kerisabe]

Im also having the same problem with lost of the lower end torque. It was much worst when I had the GruppeM intake on the car. Right now Im running the stock airbox with the K&N drop-in filter and it felt alot better in the lower end. My exhaust setup is, technik headers - magnaflow race cats - xpipe - high flow resonators (glasspacks) - eisenmann sport quad. The shop kept the stock diameter of the pipes. And the torque between 0 to below 3k is pretty BAD I must say. Any of u guys have any idea on what routes should I take to fix this problem? Might it be the spark plugs, coils, fuel filter??? One of the post O2 sensor has been replaced during the headers installation since the shop couldnt take it off the stock manifold. The rest 02 sensors are still original parts with around 126K kilometers.

[330i ZHP]

All this talk of loss of low end power makes me rethink the headers et al...

[DarXide]

All this talk of loss of low end power makes me rethink the headers et al...

With a TS I wouldn't worry about it..:str8pimpi

[LagunaBlau///M3]

All this talk of loss of low end power makes me rethink the headers et al...


yeah with a TS is gonna get that exhaust gases out faster then it would with a manifold

[pei330ci]

It is possible that that car is running lean. Not due to failure of any engine component, but due to a change in the volumetric efficiency of the engine. I went through this with an exhaust change about a year ago. The only way to prove it is to get the car on a dyno to record the AFR and power output.

14.5:1 AFR may be nice for emissions, but it doesn't make the best power.

Rito's car is a monster...

Edit: The original poster seems to have his car running rich not lean. THAT issue has me stumped.

[ritos530i]

Im also having the same problem with lost of the lower end torque. It was much worst when I had the GruppeM intake on the car. Right now Im running the stock airbox with the K&N drop-in filter and it felt alot better in the lower end. My exhaust setup is, technik headers - magnaflow race cats - xpipe - high flow resonators (glasspacks) - eisenmann sport quad. The shop kept the stock diameter of the pipes. And the torque between 0 to below 3k is pretty BAD I must say. Any of u guys have any idea on what routes should I take to fix this problem? Might it be the spark plugs, coils, fuel filter??? One of the post O2 sensor has been replaced during the headers installation since the shop couldnt take it off the stock manifold. The rest 02 sensors are still original parts with around 126K kilometers.

What i would do if i was just is just get rid of the quad exhaust and make it a single pipe from the resonator and see how it performs. My thinking is that if you open it up more you will gain top end and you have to find the happy medium between the two. When you do your dyno you should have improved your topend or final hp and even thought with the single pipe you loose on the final bhp you may be making more power within the lower rpms but you will have to play with this to find out. Just have a shop build you a exhaust pipe from the resonator, it should not be more than 100 bucks.

All you can do is try it.
Rito

[kerisabe]

What i would do if i was just is just get rid of the quad exhaust and make it a single pipe from the resonator and see how it performs. My thinking is that if you open it up more you will gain top end and you have to find the happy medium between the two. When you do your dyno you should have improved your topend or final hp and even thought with the single pipe you loose on the final bhp you may be making more power within the lower rpms but you will have to play with this to find out. Just have a shop build you a exhaust pipe from the resonator, it should not be more than 100 bucks.

All you can do is try it.
Rito

The thing is..the resonator is located right before the exhaust, about 1-1.5 feet from where the exhaust is. I was thinkin of taking off the high flow resonators I have now, cut the x-pipe in half, build a single 2.25" from there, put back the stock 2nd resonator and use the other half of the x-pipe to connect the single 2.25" pipe to the exhaust. Will that make a diff? I dunno if Im going to sell my quad exhaust since my rear bumper has the quad cutout on the passenger side.

[ritos530i]

Cutting the resonator and moving it back is not an issue.
You should have two pipes coming from headers and move it back towards the front. although it doesn't make sense that they relocated the resonator which could be an issue too. If i was me i would remove the resonator and muffler and just add a silencer to the end of the pipes to control sound. Only when you are out racing you can unplug the thing.
I am reaching but the people who could tell you more is the exhaust shop. just trying to help. I can tell you its all trial an error at this point.

[kerisabe]

Cutting the resonator and moving it back is not an issue.
You should have two pipes coming from headers and move it back towards the front. although it doesn't make sense that they relocated the resonator which could be an issue too. If i was me i would remove the resonator and muffler and just add a silencer to the end of the pipes to control sound. Only when you are out racing you can unplug the thing.
I am reaching but the people who could tell you more is the exhaust shop. just trying to help. I can tell you its all trial an error at this point.

Ive spent enough at the exhaust shop that's why Ive promised myself not to spend anymore on exhaust. When I say enough it's really enough. Ill see what the shop can do later if Im bored. Thanks for your suggestions, appreciate it. :)