Longtube headers = no power???????

[03Steve]

AMEN

 

[bassin247]

I posted THIS THREAD and THIS THREAD about my bassani mid-lengths. The first one is dyno results and the second thread is track results.

Pay no attention to the wacky air/fuel. The sensor was wacked.

Although I did lose on peak TQ I gained on Peak HP and my TQ curve was flatter with gains in the upper RPM area. I did manage to run 2 tenths faster in the 1/4 than I did prior to the headers and without the Accufab TB/Inlet I had and sold.

I do have an exhaust leak. I am going to try to battle it this weekend.

 

[moridin2004]

Originally posted by 03Steve
I have a bigger blower... :shrug:

Hmmm...They may even be too big and too long for the bigger blower. It would take some calculations to figure out basic flow rates at different RPM's. I don't know the flow rates of the 4.6L heads and your boost curve on the blower. Nor do I know the flow rates of the headers themselves. Maybe when I move out and graduate from college I may set up a flow bench so I can start finding some of this stuff out.

Another thing...Are the O2 sensors relocated down the piping? I don't know if this makes a difference, but if they aren't heated sensors (because with the stock manifolds I believe they are close enough to be heated by the motor) they may not work properly? Then again, it operates in closed loop under full throttle.

Who knows?:shrug:

 

[Jim Vaccaro]

We keep debateing the dyno numbers,boost gain or loss..Why not get the cars down the old 1/4 mile...The Big boosted Eatons Peak sooner and LT's will help them also.Without LT's my car needed to be shifted at 6100 for best results ,,now with LT's i shift @ 6500 for best results.Having less boost to make more power and a broader powerband is also helpfull.
Any way you look at it the setup has to work together..
Every mod gets scrutized and that's good..Idlers can help when needed but for the most part if you have vthe right pulley,or Pulleys and right belt they are BLING<BLING..Guys spend a fortune on BLING and then want to justify why not to get Long Tubes.
What pulley? What upper and Lower Pulley setup?,What tune?
Seems after all that's tried ,The restriction on this motor is the Blower(HEATON)So there comes a time that headers ,,LONG, MID leanth or Shorty's will help.

 

[Crazy03]

Eaton-ls1 I talked to you before about the headers install. I live in hayward. I had a bassani X-pipe with cats and bassani cat-back with the K&N air filter and my car dynoed 410 HP and 385 TQ. I put the longtubes 1 5/8 with off road X-pipe on with a 3.5 pulley and Dynoed 426 and 400 TQ. The boost was still at 8 Pounds with the 3.5. So my setup I did gain a few horsepower and some TQ. I didnt loose anything.
What size headers do you have on your car. If you have the 1 3/4 I have seen people loose power with those. Also just to let you know with the longtubes, cat back, upr cold air, 2.8 pulley, and idler I dynoed 460Hp and 455 TQ and the eaton was only putting out 11 pounds. Hope this helps

 

[raiders03]

Crazy03
I have the Kooks longtube headers. I thought they only had one size for the 03 Cobra, 1 5/8. I am not positive. I dynoed 450HP and 460 TQ. with and without the headers. I think one of my fuel pumps might be failing though because my car is running to lean after 5800RPM and Byron can not get it to tune correctly. He could not get enough fuel at the top end. I am not sure if this would effect my results. I have the exact same setup as you. I do not know how much boost I am running. I never checked it with a boost gauge.

 

[raiders03]

ttp

 

[raiders03]

ttt

 

[Crazy03]

They also make a 1 3/4 headers for the cobra. I never had a problem with the A/f ratio. I wish I could help. Do you have a idler pulley, and what kind of plugs and gap are you using?

 

[raiders03]

I have a idler pulley and have plugs gapped at 40. I think they only have one header size for the 03 Cobra. What kind of headers do you have?

 

[sambandit]

I have 1 5/8 kooks, they do make an 1 3/4 as well.

 

[03Steve]

Sounds like a pegged MAF on your fuel. If your tuner does not have data logging, I have a way you can test your MAF. PM me for details...

 

[Crazy03]

I had the 1 5/8 headers but kooks also make a 1 3/4 headers. Also how was you power chart was it choppy at all. Mine was choppy, then I changed my plug gap to 35 and it was smooth after that. It really helped alot

 

[Crowley]

This is an intersting thread. I would think that the motor would respond nicely to Long Tubes. Could there be some sort of tuneing issue after a long tube install?

Has anyone installed long tubes and then re dyno tuned?

thanks,
Crowley

 

[raiders03]

Crazy03
No my chart was not that choppy. I just remembered they are gapped at .35 not .40. Where did you have your car tuned? Do you have cats? Only places I know of around here (I live in Dublin) are Apex and the Mustang Ranch. I will actually be at Apex this Sat trying to fix my A/F problem.

 

[raiders03]

I just checked and the headers sent to me were 1 5/8 unless there was a mistake made.

 

[raiders03]

ttt

 

[03Steve]

Get my PM?

 

[raiders03]

just got it. Thanks for your help

 

[BAD03SVT]

dont know what you guys are saying i put my coated BBk long tubes on with off road h pipe and the bitch seemed to be a different car pulls much stronger now. my full exhaust car with the AR filter went faster than my two co worker with pulley swaps and catted x pipes and cat backs. i dont get it...