Headers made my truck slower!?!?!?!?

dubleedgeblade · 07-30-2010, 02:08 PM

Alright I have been dealing with this for a while because I have been swamped at work. Around Thanksgiving I installed a BD PP (set to regular tune w/ 2* advance and wot mod), injen intake, and added new magnaflow cats and magnaflow 18" muffler to stock pipes. So the truck was bad a** and I was really happy with the feel and response! Christmas rolls around and my girl gets me DT shorties installed, my truck now sounds sick. However I feel a lull in power off the line and it just doesn't feel rightand it seems like it takes longer to shift. Am I over reacting here or is this something that other people have dealt with. Is the air to fuel ratio out of wack or what?? I thought maybe new gears or an upgrade to Uprev tune would help. I have too many mods to my truck to not be happy with it!!! Any and all suggestions would be greatly appreciated....

Thanks
Ricky

wguy00 · 07-30-2010, 02:15 PM

Try resetting the ECM.

O-FiveCC · 07-30-2010, 02:19 PM

All you really need is an Uprev tune. Headers make a huge difference on this truck, you should notice a lot more performance. Your AFR is probably way off and you need a good custom tune

deerslayer · 07-30-2010, 05:29 PM

The headers moved your power band higher up in the rpm's. You should feels more power after 3500 rpm's. If it's slower off the line I'd say it's not much. Your AFR if anything would be a little leaner but that wouldn't make it slower IMO.

Sell the PP and get a BDGT to be sure, or just go get a dyno with AFR numbers before you spend over $500 on a custom tune.

titantriper06 · 07-30-2010, 05:49 PM

you have almost the exact same setup as me... and i noticed the same exact thing. well after a while i realized what dearslayer means, its more power higher up. Also, my spark plugs were filthy, i changed them when i installed nitrous and then i noticed a HUGE difference so it might be a good idea to check your plugs. anyway im getting uprev on mon il see if it was worth it.

O-FiveCC · 07-30-2010, 06:35 PM

When I installed headers, my power from 0 mph felt like it doubled. For me, I had a large increase in power from 0 all the way up, not sure if the Nismo's where just that much better or what.....You shouldn't be losing power down low with stock b-pipes, and stock exhaust pipes.

firelife25 · 07-30-2010, 09:07 PM

Quote:

Originally Posted by titantriper06

you have almost the exact same setup as me... and i noticed the same exact thing. well after a while i realized what dearslayer means, its more power higher up. Also, my spark plugs were filthy, i changed them when i installed nitrous and then i noticed a HUGE difference so it might be a good idea to check your plugs. anyway im getting uprev on mon il see if it was worth it.

what all do you have done to your truck? never see you post on here...do you race your t? if so why not come to the race meets we have?whats your 1/4 mile times

**DanBlp** · 07-30-2010, 10:02 PM

What is your O2 sensor situation with the shorties? What are your WOT AFRs?
Shorties are tailored to bottom end so you should not be losing power off the line post install. Without answers to the questions above, I would guess that post header install, you mixtures are jacked up; most likely due to O2 sensor placement and/or connection and/or functionality and/or existence in your system. Being an 07', your rear O2 sensors are very critical.

titantriper06 · 07-30-2010, 10:28 PM

Quote:

Originally Posted by firelife25

what all do you have done to your truck? never see you post on here...do you race your t? if so why not come to the race meets we have?whats your 1/4 mile times

im all about racing my truck, in fact just 15 mins ago i did my last run at qualcom stadium, its not much an 1/8 mile but its all i can get. right now i got nitrous injen cai, jba headers and uprev arrives on mon. and i do have a thread asking if anyone wants to race with me at qualcom. theres no 1/4 near sd.

DINSTAAR · 07-30-2010, 10:41 PM

I had the same problem when I installed my DTLTs. Along with the header install I put in walker direct bpipes also so I have no cats or resos. Anyway, with no BDGT tune my AFR was all jacked up...I had NO power. With the BDGT my AFR was good but by the time I got it installed, I already had uprev on the way. Now with only the base tune using 89 oct...uprev blows BDGT out of the water. I still haven't got to do my 0-60 runs since they fixed my base tune so really...I'm untuned still. The GT will do it's job, but with uprev...all I can do when I gun it is smile and make sure I say on the road.

P.S. I did lose bottom end but what I picked up above 3k makes up for it and more.

pd298 · 07-30-2010, 10:42 PM

Sounds like driver error to me!! lol jk

import2nr · 07-31-2010, 12:32 AM

You need a tune .. Afr's are probably out of whack.

**DanBlp** · 07-31-2010, 06:24 AM

Quote:

Originally Posted by DINSTAAR

P.S. I did lose bottom end but what I picked up above 3k makes up for it and more.

DINSTAAR, you are on the right path. You will be pleasantly surprised to find out that when UpRev gets your tune right, then your truck has about 2 weeks to learn it (depending on driving style and distance), your bottom end should come back.

Though your LTs are more tailored to mid and top end, you really shouldn't loose bottom end once everything is dialed back in.

b2sdad · 07-31-2010, 01:32 PM

great info guys! cant wait for my uprev!

dubleedgeblade · 08-01-2010, 05:55 PM

See this is why I like this site, you ask a question and you get intelligent feed back. Lots of useful info! Looking back I would have been happier leaving the headers off, IMO. I am sure I will change my mind after I upgrade to Uprev!! I do feel strong in higher rpms but s*** if i can't smoke em off the line, whats the point???? Like I said thanks guys ... much help!