1UZFE exhaust experts

[stevechumo]

Drifty325,

A single 2.5" might not do anything to increase performace. The stock 1UZFE already has 2.5" at the single section, and it's very restrictive. So you may want to increase the performance while doing the swap to save you time, instead of staying as stock. A single 2.5" has smaller inner flow volumn than both 2.25" combined. If you already have hi-flow headers, then it'll be restricted again, then so what's the point of running hi-flow headers. Noise or quietness also depends on other factors such as the muffler type, resonator type, and straight or curved pipes.

 

[drifty325i]

Drifty325,

A single 2.5" might not do anything to increase performace. The stock 1UZFE already has 2.5" at the single section, and it's very restrictive. So you may want to increase the performance while doing the swap to save you time, instead of staying as stock. A single 2.5" has smaller inner flow volumn than both 2.25" combined. If you already have hi-flow headers, then it'll be restricted again, then so what's the point of running hi-flow headers. Noise or quietness also depends on other factors such as the muffler type, resonator type, and straight or curved pipes.

Well ive been told by some very reliable people (jbrady,zuffen,lambo) that the 2.5 inch will be perfect for the 1uzfe engine. Alot of people have said the 3inch is to big for the 1uz and you lose low and mid range tq, you may gain a little up top over the 2.5 but not worth it in there opinions. Also in my case the car is very low and i dont think a 3inch would cope to well

 

[drifty325i]

Drifty325,

A single 2.5" might not do anything to increase performace. The stock 1UZFE already has 2.5" at the single section, and it's very restrictive. So you may want to increase the performance while doing the swap to save you time, instead of staying as stock. A single 2.5" has smaller inner flow volumn than both 2.25" combined. If you already have hi-flow headers, then it'll be restricted again, then so what's the point of running hi-flow headers. Noise or quietness also depends on other factors such as the muffler type, resonator type, and straight or curved pipes.

Anyone have any thoughts about this? am i under doing my car with a 2.5 inch mandrel bent exhaust?

 

[drifty325i]

Bearing in mind the factory exhaust has several restrictive mufflers, its not mandrel bent, has cat converters, is alot longer.

 

[gloverman]

I think 2.5 will suit your application the best. Cheers Kelvin

 

[mshawari1]

Diameter = 2.5" = 6.35 cm - Area = 31.6 cm2
Diameter = 3" = 7.62 cm – Area = 45.6 cm2

With 16 % more in the diameter you will get 31% more in size and air flow !!!

But 2.5" is more than enough for 1UZ 4000 cc .
For GM 6500cc 2.5" is installed ​

 

[JBrady]

Drifty325,

A single 2.5" might not do anything to increase performace. The stock 1UZFE already has 2.5" at the single section, and it's very restrictive. So you may want to increase the performance while doing the swap to save you time, instead of staying as stock. A single 2.5" has smaller inner flow volumn than both 2.25" combined. If you already have hi-flow headers, then it'll be restricted again, then so what's the point of running hi-flow headers. Noise or quietness also depends on other factors such as the muffler type, resonator type, and straight or curved pipes.

Steve, the stock single section is 60mm = 2.36". This is the same size used on the 300hp/325tq 3uzfe GS430. As long as the transitions are smooth a 2.5" exhaust pipe is NOT a restriction below 350hp.

 

[drifty325i]

Awesome thats what i wanted to here, cheers fellas

 

[drifty325i]

Heres some picks of the unfinished extractors, we have tidyed them up now and wraped them to looking good. Also the engine mounts are not finished at all

 

[drifty325i]

And more of the finished product, note the right hand bank extractors had to clear the steering coloum

 

[drifty325i]

Note the setup in size for the pipes on the primaries
All exhaust wraped

 

[madmont]

Hey I can see those pictures except for the last one ???

 

[drifty325i]

Hey I can see those pictures except for the last one ???

Hmmm they all seem to work for me?

 

[rivmasta]

nice mate! looks the money - hopefully it works as good as it looks!

What are the final specs you went with?

 

[drifty325i]

nice mate! looks the money - hopefully it works as good as it looks!

What are the final specs you went with?

From memory, the primaries start with 1 5/8inch for 150mm then upto 1.75inch for the rest of the primaries, from there there is a 4 into 1 collector moving into twin 2 1/4 inch secondaries for around 800mm then into a nice y pipe, to a single 2.5inch mandrel bend exhaust with 1 resonator and 1 straight thru muffler at the back with twin tips

 

[rivmasta]

intrusting - why the step up in the primaries?

 

[drifty325i]

intrusting - why the step up in the primaries?

Not really sure lol, thats what my exhaust guy and some of his peers said works best on the 1uz (and they do alot of them)

 

[stevechumo]

They look very nice. :Eyecrazy: But here's what I think. I see that the right & left sides don't have the same length. As far as I know, equal size for both sides are critical to the N/A engine. Also, equal length of the individual runner is also important. They won't have equal pulses & backpressure. They may affect on the Explanation? I forgot because it's been a long time on this for me. You may ask JBrady and he's an expert on the exhaust.

One thing that I know for sure is if your exhaust is built for a turbo system, then equal size & length aren't that critical, except if it's for really high horsepower for tracks or daily streets.

 

[drifty325i]

They look very nice. :Eyecrazy: But here's what I think. I see that the right & left sides don't have the same length. As far as I know, equal size for both sides are critical to the N/A engine. Also, equal length of the individual runner is also important. They won't have equal pulses & backpressure. They may affect on the Explanation? I forgot because it's been a long time on this for me. You may ask JBrady and he's an expert on the exhaust.

One thing that I know for sure is if your exhaust is built for a turbo system, then equal size & length aren't that critical, except if it's for really high horsepower for tracks or daily streets.

Thanks for you comments Steve ,
Yes you are correct in saying they are not quite equal length, and yes it is better to have equal length but in my case it was almost impossible to get equal length. We are working on the theory that these have to be alot better than stock logs etc lol, And are as good as we can get we feel. Also yes the right hand sides are slightly shorter than the lefts ,but the secondry is slightly longer on the right.

 

[rivmasta]

Thanks for you comments Steve ,
Yes you are correct in saying they are not quite equal length, and yes it is better to have equal length but in my case it was almost impossible to get equal length. We are working on the theory that these have to be alot better than stock logs etc lol, And are as good as we can get we feel. Also yes the right hand sides are slightly shorter than the lefts ,but the secondry is slightly longer on the right.

Yeah, youve gotta hate facing up to practicality and the realms of the possible!!! To get equal distance we had to run ours pipes outside of the chassis... not an option in your car!