JANNETTY RACING HEADER TEST RESULTS

[JANNETTYRACING]

Bump for further discussion.

[quickvert1]

great info thanx ted..free bump..time to take off my 1 3/4" LG long tubes for some ARH 2" system...

[revived]

Originally Posted by JANNETTYRACING

Bump for further discussion.

So, with a tune how much horsepower more are we going to see over not getting one.


You said the air and fuel was unaffected or atleast remained safe and normal, so its safe to run a LT header without a tune right?

[JANNETTYRACING]

Originally Posted by quickvert1

great info thanx ted..free bump..time to take off my 1 3/4" LG long tubes for some ARH 2" system...

Thanks Paul.

Originally Posted by revived

So, with a tune how much horsepower more are we going to see over not getting one.


You said the air and fuel was unaffected or atleast remained safe and normal, so its safe to run a LT header without a tune right?

There is way more to tuning than just a HP number.

Yes headers alone with no other changes will not change AFR.

A custom tune gets rid of torque management, skip shift, turns the fans on earlier, gets rid of annoying codes, will correct for CAI MAF calibration, raise the rev limiter 200, and get rid of the speed limiter.

Basically parts make power, custom tuning makes the parts work correctly.

There is about 5-10 RWHP over stock tuning with just headers alone.

Ted.

[Bretts]

I am installing solo highflow cats, is there any point to putting shorty coated headers on?the rest is npp exhaust&bw t.b. and cai to round out both ends, and I am not wanting to tune, +want to avoid the codes being thrown is this likely?. I'm also putting the 391 gears g.m.(not related). My one thought is will this create a lean mixture condition or will the car compensate for the extra air flow? thanks in advance

[JANNETTYRACING]

Still getting a lot of requests on this subject, Enjoy!!

[JANNETTYRACING]

Great read, Great info has not been bumped since 2015

[HOXXOH]

Free bump for you.
This thread was mentioned on the C6 Vette forum due to a mention that larger primaries produce more power. Your dyno results showed 2" produced the most, however that was on a bone stock LS3 with a header change only. That you use 1 7/8" headers on much higher HP packages (up to 650) has confused several people. It seems they don't understand that header sizing is chosen to complement all the other components, rather than picking parts based on what some random test showed for that individual part. Some of the early responses on this thread jumped on the bigger is better bandwagon too. I suppose that's fine if it's the only mod someone ever plans to do, but it might make a difference to the customer who sees headers as just the first step of many. I hope this comment helps people to understand that headers are just one piece of a much bigger puzzle.
BTW, my '08 LS3 bolton Vette runs high 10's with 1 3/4" headers, so I do get a little respect over there.

[JANNETTYRACING]

Originally Posted by HOXXOH

Free bump for you.
This thread was mentioned on the C6 Vette forum due to a mention that larger primaries produce more power. Your dyno results showed 2" produced the most, however that was on a bone stock LS3 with a header change only. That you use 1 7/8" headers on much higher HP packages (up to 650) has confused several people. It seems they don't understand that header sizing is chosen to complement all the other components, rather than picking parts based on what some random test showed for that individual part. Some of the early responses on this thread jumped on the bigger is better bandwagon too. I suppose that's fine if it's the only mod someone ever plans to do, but it might make a difference to the customer who sees headers as just the first step of many. I hope this comment helps people to understand that headers are just one piece of a much bigger puzzle.
BTW, my '08 LS3 bolton Vette runs high 10's with 1 3/4" headers, so I do get a little respect over there.

Thank you for the bump and I am Sorry for the confusion, but the test was exactly what you said it was for, find out which headers work best by themselves.

When putting packages together we have to consider market pricing and what the rest of the package entails.

1 7/8 get the job done at a lower price point.

It also depends if we are talking PD blower or Centrifugal blower, the PD blower don't much care what size the header are up to about 700 HP then we start to see incremental gains.

On the other hand a Centri blower will respond to the larger headers much better we have seen as much at 20 RWHP above 700 RWHP.

I hope this clears things up a bit.

[Gasoholic]

I picked up my new heads last week, they're L92 heads rebuilt by Livernois.
I measured the exhaust ports and they are 1.70" using my digital dial indicator.
I believe that is slightly larger than OE which makes sense as these heads have been ported.
I dont pretend to be an expert on this but it would seem that 1.70 would match very closely to 1 7/8ths. That has me thinking 2" headers would pretty much be a waste. Especially if you are running stock heads.

[JANNETTYRACING]

Originally Posted by Gasoholic

I picked up my new heads last week, they're L92 heads rebuilt by Livernois.
I measured the exhaust ports and they are 1.70" using my digital dial indicator.
I believe that is slightly larger than OE which makes sense as these heads have been ported.
I dont pretend to be an expert on this but it would seem that 1.70 would match very closely to 1 7/8ths. That has me thinking 2" headers would pretty much be a waste. Especially if you are running stock heads.

When the smaller port dumps in to a larger tube there is pressure drop which helps expel the spent gases from the chamber making more room for fresh air fuel charge on the next cycle.

Note there is a point of too big but 2 inch is not it.

Ted.

[silversleeper]

Originally Posted by mtbikerinme83

I'm sorry, Torque is on the right side of the graph.
It's from 2500 to 3200 rpm the torque curve is a flat line with no gain in torque. I wasn't sure if that was torque management doing that, or if it was just the operators foot not being to the floor.

Originally Posted by JANNETTYRACING

Thanks Paul.
There is way more to tuning than just a HP number.
Yes headers alone with no other changes will not change AFR.
A custom tune gets rid of torque management, skip shift, turns the fans on earlier, gets rid of annoying codes, will correct for CAI MAF calibration, raise the rev limiter 200, and get rid of the speed limiter.
Basically parts make power, custom tuning makes the parts work correctly.
There is about 5-10 RWHP over stock tuning with just headers alone.
Ted.

I appreciated the test. It shows exactly what to expect in hp and torque gains with each size. Reminds me of a good cam test that shows the larger cam makes more top end hp. A smaller cam and header diameter might be adequate to meet our budget and street hp goals.
I wanted to ask this question about the dyno graph and it wasn't answered yet.
On the stock dyno run, there is an obvious flat spot in torque 2500 to 3600rpm.
I might see some hint of it in the header and tune graphs but it is mostly gone.
What was it? Something mentioned in your tune? Do all stock cars show that problem?

[JANNETTYRACING]

Originally Posted by silversleeper

I appreciated the test. It shows exactly what to expect in hp and torque gains with each size. Reminds me of a good cam test that shows the larger cam makes more top end hp. A smaller cam and header diameter might be adequate to meet our budget and street hp goals.
I wanted to ask this question about the dyno graph and it wasn't answered yet.
On the stock dyno run, there is an obvious flat spot in torque 2500 to 3600rpm.
I might see some hint of it in the header and tune graphs but it is mostly gone.
What was it? Something mentioned in your tune? Do all stock cars show that problem?

All Stock LS3 cars produce that exact power curve, it is the intake, cylinder head, cam, manifold, cats combo.

There is an air flow deficiency that improves with the addition of long tube headers due to proper scavenging.

Ted.

[mmiiller]

Originally Posted by JANNETTYRACING

Thanks Paul.



There is way more to tuning than just a HP number.

Yes headers alone with no other changes will not change AFR.

A custom tune gets rid of torque management, skip shift, turns the fans on earlier, gets rid of annoying codes, will correct for CAI MAF calibration, raise the rev limiter 200, and get rid of the speed limiter.

Basically parts make power, custom tuning makes the parts work correctly.

There is about 5-10 RWHP over stock tuning with just headers alone.

Ted.

Hello, Ted

If you don’t get rid of torque management, what kind of funky things happen when doing the quarter mile drag? Thanks