Downpipe modifications
10-23-06, 08:52 AM
#46
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Ouch, that is a lot of money for only $49 HP. For $13K, you could probably build your own turbo system and put some lower compression parts in the engine. The only real hurtle would be the custom tune.
These engines are tuned very conservatively, tuning alone would probably yeield about 10 HP.
These engines are tuned very conservatively, tuning alone would probably yeield about 10 HP.
I have to remember that for the 1999 model year, the RX300 was not too bad in terms of power compared to its competitors.
10-23-06, 10:34 PM
#47
Bosal Downpipe Camry V6
Lexmex,
It is great you upgraded to bigger downpipe, I just found out Bosal makes a downpipe for 94 Camry V6, same 1mzfe engine.
The downpipe can be better (but far more complexity and expensive) if they have equal length from the exhaust manifold headers to the catalytic converter. See Bosal (www.bosalna.com) picture which gives an example. The same can be said with stock manifold headers, you have an excellent picture. The amazing thing is all three stock exhaust manifold "holes" have different length in the same bank, my Acura only has the middle one shorter than outer two.
I would be happy if Megan Racing makes a pair of 1MZFE manifold exhaust headers, I think the downpipe will have to be custom made for RX just like you have done here.
It is great you upgraded to bigger downpipe, I just found out Bosal makes a downpipe for 94 Camry V6, same 1mzfe engine.
The downpipe can be better (but far more complexity and expensive) if they have equal length from the exhaust manifold headers to the catalytic converter. See Bosal (www.bosalna.com) picture which gives an example. The same can be said with stock manifold headers, you have an excellent picture. The amazing thing is all three stock exhaust manifold "holes" have different length in the same bank, my Acura only has the middle one shorter than outer two.
I would be happy if Megan Racing makes a pair of 1MZFE manifold exhaust headers, I think the downpipe will have to be custom made for RX just like you have done here.
Last edited by TunedRX300; 10-23-06 at 10:38 PM.
10-24-06, 06:04 AM
#48
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Thread Starter
Lexmex,
It is great you upgraded to bigger downpipe, I just found out Bosal makes a downpipe for 94 Camry V6, same 1mzfe engine.
The downpipe can be better (but far more complexity and expensive) if they have equal length from the exhaust manifold headers to the catalytic converter. See Bosal (www.bosalna.com) picture which gives an example. The same can be said with stock manifold headers, you have an excellent picture. The amazing thing is all three stock exhaust manifold "holes" have different length in the same bank, my Acura only has the middle one shorter than outer two.
I would be happy if Megan Racing makes a pair of 1MZFE manifold exhaust headers, I think the downpipe will have to be custom made for RX just like you have done here.
It is great you upgraded to bigger downpipe, I just found out Bosal makes a downpipe for 94 Camry V6, same 1mzfe engine.
The downpipe can be better (but far more complexity and expensive) if they have equal length from the exhaust manifold headers to the catalytic converter. See Bosal (www.bosalna.com) picture which gives an example. The same can be said with stock manifold headers, you have an excellent picture. The amazing thing is all three stock exhaust manifold "holes" have different length in the same bank, my Acura only has the middle one shorter than outer two.
I would be happy if Megan Racing makes a pair of 1MZFE manifold exhaust headers, I think the downpipe will have to be custom made for RX just like you have done here.
Off the rear manifold it would have to jut out a little bit and then shoot literally straight down as shown in the Bosal example, if I were to adopt in the the RX300. I think it might be of equal length then.
When I used to talk about a turbo, I had the idea that it would be fitted on the piping leading off the exhaust manifold behind the engine. This no doubt would have a slight resistance effect that I would hope would equalize the effect.
I still feel at the moment the ECM has to learn this new modification to its system to get the performance. For the past few driving days it seems to have got a little more pep in it than on the weekend.
In the future, I do want to get the manifolds redone similar to what Megan is trying to do. Maybe I can just buy the top pieces when they are done.
10-24-06, 12:28 PM
#49
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would the bosalna downpipe work for the rx300? cause my catalytic converter has crack inside i think ... cause i hear a knocking sound and i took it to the shop they lift my car up and they moved the catalytic coverter around you hear something move around inside.
10-24-06, 12:47 PM
#50
That is a sign of failing catalytic convertor. No one knows Bosal fits the RX unless one buy off Ebay and try it out. But it is very easy to modify since Bosal downpipe have two flexible parts, any muffler shop can cut the flex part and weld customized short connecting pipes to make it fit.
10-24-06, 01:21 PM
#51
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Thread Starter
I had my old OEM cat get hit by road debris. A dent and also the rattling inside. Reason I have my Magnaflow now.
Now, it is possible, but not in your case that a faulty gasket (usually loose or corroded as shown below can cause this). However, usually piece of the honeycomb in the cat has turned into honeycomb cereal.
Now, it is possible, but not in your case that a faulty gasket (usually loose or corroded as shown below can cause this). However, usually piece of the honeycomb in the cat has turned into honeycomb cereal.
10-24-06, 01:24 PM
#52
Super Moderator
Thread Starter
But there is probably a craps game going on inside your cat.
Here is a picture of the interior of my Magnaflow Highflow Cat.
There is likely a crack in there and material came loose.
As far as that Bosal, I could measure the piping I have later today at Hangar 1 or if not, on the weekend with my uncle and perhaps we can ask Bosal for the specifications to see if they match up.
The one saving grace so far is that my modifications have not thrown a CEL, so that is a plus for all of us.
Here is a picture of the interior of my Magnaflow Highflow Cat.
There is likely a crack in there and material came loose.
As far as that Bosal, I could measure the piping I have later today at Hangar 1 or if not, on the weekend with my uncle and perhaps we can ask Bosal for the specifications to see if they match up.
The one saving grace so far is that my modifications have not thrown a CEL, so that is a plus for all of us.
10-24-06, 01:38 PM
#53
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Thread Starter
I have a nasty rattle and vibration at the juncture of this pipe and the Resonator (a Sankei from an Accord) that I hope to fix today. Vibrates in D except when in motion, but surprisingly not when I am in P.
I also have my suspicions there is a leak there as I can hear something other than rattling under slight acceleration (which could cause torque problems).
I also have my suspicions there is a leak there as I can hear something other than rattling under slight acceleration (which could cause torque problems).
10-24-06, 08:46 PM
#55
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Thread Starter
BTW, I had to work late (still am) and could not stop by for measurements at Hangar 1. May not get to it until Thursday with my pace of work. Saturday morning I could definitely get over there.
I also noticed that on the way home (I go up in elevation approximately 1,000 feet from work to home), that when I stepped on the pedal on a long stretch of road, it is getting much harder to push down, so I think the ECM is finally getting it and freeing up the extra power.
10-25-06, 03:51 AM
#56
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lexmex when you did your downpipe ... did your check engine light come on cause of o2 sensor ? cause someone told me if i do a custom downpipe my check engine might come on...
10-25-06, 04:42 AM
#57
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However, whoever told you that is correct. Some vehicle are very finicky. My original concern was when we had to replace the precats with straightpipe, but nothing. Remember, I was mentioning earlier that our friends with Solaras that have 1MZFEs often do not have those precats in certain states, so I have a hunch no issue.
There are things known as O2 eliminators that act like dummy oxygen sensors that could be used if I d get a CEL.
10-25-06, 11:50 AM
#58
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No CELS whatsoever.
However, whoever told you that is correct. Some vehicle are very finicky. My original concern was when we had to replace the precats with straightpipe, but nothing. Remember, I was mentioning earlier that our friends with Solaras that have 1MZFEs often do not have those precats in certain states, so I have a hunch no issue.
There are things known as O2 eliminators that act like dummy oxygen sensors that could be used if I d get a CEL.
However, whoever told you that is correct. Some vehicle are very finicky. My original concern was when we had to replace the precats with straightpipe, but nothing. Remember, I was mentioning earlier that our friends with Solaras that have 1MZFEs often do not have those precats in certain states, so I have a hunch no issue.
There are things known as O2 eliminators that act like dummy oxygen sensors that could be used if I d get a CEL.
10-25-06, 12:25 PM
#59
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10-26-06, 07:02 AM
#60
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If you notice on my Saturday night videos, especially the one where my father is the co-pilot, there is a slight low hum (a pause) then the motor comes alive, I have felt this decreasing and a definite increase in torque every day since, so it seems the ECM is learning the new downpipe. As with my URD pulley, it too about a week of driving.