Unequal vs. Equal length headers?

[Nissota]

Originally Posted by Shiv@Openflash

FWIW, the UEL headers we tested made more power peak and more low end torque than the EL headers we tested. No only did it make power peak power, it also made more power in the 5500-6500rpm range which makes for a broader (less peaky) power curve. It surprised me too.

Shiv, Do you have a graph that back your findings on both EL and UEL?

[tyler_win_photo]

Go Tomei UEL and call it good. Cheap and good gains (more power throughout compared to Tomei's EL)

[echo419]

I just want something to drown out all the ticking and general bs sounds coming from the car at stock.

[Foobar]

Originally Posted by echo419

I just want something to drown out all the ticking and general bs sounds coming from the car at stock.

3" exhaust + muffler delete will do that nicely.

[Shiv@Openflash]

Originally Posted by Nissota

Shiv, Do you have a graph that back your findings on both EL and UEL?

Yes
http://www.ft86club.com/forums/showp...58&postcount=1

[Wayno]

Don't forget long tube EL which fixes both torque dip and top end afaik

[KoolBRZ]

I'm running the 2.062 UEL 91 Oct stage 2 tune on my AR header, and I like the way it runs with this tune, better than the EL tune. Looking closely at my header, a "TOP SPEED PRO-1 Performance Header Straight Flex Pipe", I've just noticed that the 2 front primaries are shorter than the rear primaries, so it is a UEL header! Attached is a pic of the header.
I will be Dyno testing 3-5 tunes on Dec 5th with my controversial Anti-Reversion header. I will be testing the unaltered version of the same header the following week and we'll see which headers and which tunes work the best.

[Andrew025]

Originally Posted by KoolBRZ

I'm running the 2.062 UEL 91 Oct stage 2 tune on my AR header, and I like the way it runs with this tune, better than the EL tune. Looking closely at my header, a "TOP SPEED PRO-1 Performance Header Straight Flex Pipe", I've just noticed that the 2 front primaries are shorter than the rear primaries, so it is a UEL header! Attached is a pic of the header.
I will be Dyno testing 3-5 tunes on Dec 5th with my controversial Anti-Reversion header. I will be testing the unaltered version of the same header the following week and we'll see which headers and which tunes work the best.

Technically you can say it is UEL, but you're probably better off with an EL tune considering your header looks similar in design to the OEM manifold.
What data are you using to say it runs better (I know, you said "like") with the UEL vs the EL tune?
The OFT tune looks to be designed around headers that are much more unequal.

[KoolBRZ]

Originally Posted by Andrew025

Technically you can say it is UEL, but you're probably better off with an EL tune considering your header looks similar in design to the OEM manifold.
What data are you using to say it runs better (I know, you said "like") with the UEL vs the EL tune?
The OFT tune looks to be designed around headers that are much more unequal.

When I say like, I mean like how it drives in traffic and cruising on the freeway. I've been looking for a way to increase low-end torque for automatics without changing the rear-end gears. The UEL tune doesn't accelerate as fast as the EL tune, so M/T guys would want the EL tune, while A/T guys would like the low-end torque of the UEL tune. The UEL tune proves it has more low-end torque on the freeway, getting better mileage and accelerating without needing to downshift as much. The instant MPG drops down when accelerating, no matter which gear, but doesn't drop down as low when it's in 6th gear versus 5th gear. I don't have to fear I've ruined my average MPG every time I rev up a gear, since it doesn't suck as much revving up as the EL tune, and because i can make up for lost mileage easier while cruising. I drive about 1/3rd city to 2/3rd's freeway, and averaged 28 MPG on the EL tune, and 30 on the UEL tune.

[Apoc]

Originally Posted by KoolBRZ

When I say like, I mean like how it drives in traffic and cruising on the freeway. I've been looking for a way to increase low-end torque for automatics without changing the rear-end gears. The UEL tune doesn't accelerate as fast as the EL tune, so M/T guys would want the EL tune, while A/T guys would like the low-end torque of the UEL tune. The UEL tune proves it has more low-end torque on the freeway, getting better mileage and accelerating without needing to downshift as much. The instant MPG drops down when accelerating, no matter which gear, but doesn't drop down as low when it's in 6th gear versus 5th gear. I don't have to fear I've ruined my average MPG every time I rev up a gear, since it doesn't suck as much revving up as the EL tune, and because i can make up for lost mileage easier while cruising. I drive about 1/3rd city to 2/3rd's freeway, and averaged 28 MPG on the EL tune, and 30 on the UEL tune.

Wow that is the most incorrect information I have seen. The vvt is different for a reason. Why would an EL tune be better on a UEL? The tune was optimized for best power on EL. The UEL tune is optimized to have the vvt produce the best hp and tq for UEL hence the different name.

[KoolBRZ]

Originally Posted by Apoc

Wow that is the most incorrect information I have seen. The vvt is different for a reason. Why would an EL tune be better on a UEL? The tune was optimized for best power on EL. The UEL tune is optimized to have the vvt produce the best hp and tq for UEL hence the different name.

I'm going to dyno my A/R header Dec. 5th with versions 2.0 and 2.062 EL and UEL OFT tunes. Then I can show you what I'm talking about. My A/R header is only slightly UEL, see the picture, yet the tunes are quite different, see the pic's from RR. The EL tune is VERY aggressive, the UEL not so much, yet the UEL produces beter low-end torque. I think the EL will produce more max HP, but we'll have to wait till next week to find out. I removed the proprietary pictures of the VVT tables, but you can check them yourself by opening them in RomRaider.

[Apoc]

Originally Posted by KoolBRZ

I'm going to dyno my A/R header Dec. 5th with versions 2.0 and 2.062 EL and UEL OFT tunes. Then I can show you what I'm talking about. My A/R header is only slightly UEL, see the picture, yet the tunes are quite different, see the pic's from RR. The EL tune is VERY aggressive, the UEL not so much, yet the UEL produces beter low-end torque. I think the EL will produce more max HP, but we'll have to wait till next week to find out. I removed the proprietary pictures of the VVT tables, but you can check them yourself by opening them in RomRaider.

You know nothing about how or why the tables are different. I have looked at our tunes in romraider many times and wouldn't assume one is more agressive just based on the intake or exhaust cam angles. They correspond to how much overlap and/or angle is needed to have efficient scavenging for each header type. Comparing them to determine agressiveness is not really logical. The typical tuning strategy is to adjust those tables to make the most power through the whole curve for that header. Having to flash EL tunes on manual trans with UEL headers get better power is even more illogical. HP and TQ requirements are the same with auto or manual. Also Shiv's tunes are really proprietary if anyone can download them for free off his site.