Supporting Components for Pfadt Header Installation?
Safety Car
Joined: Dec 2009
Posts: 3,724
Likes: 9
If I ever had a doubt about whether to go with the Pfadt headers, this thread has me sold.
I have one question: in one of the pics, I noticed a second O2 sensor bung in the header collector. Is this a secondary bung for use of a wideband? Is this standard on the Pfadt headers? That was the one thing I wasn't sure about - whether you had to special order a second bung for use of a wide band, because I recall having to do that when I ordered the ARHs for my truck.
Very good write-up and excellent pictures! Thanks OP. This is what these forums are for, IMV.
Tech Contributor
Joined: Jul 2002
Posts: 14,950
Likes: 264
From: St. Louis, MO
St. Jude Donor '08
Now for a bit about first impressions. I have an appointment with Dasilva Motorsports on May 11th for dyno tuning. So far, I have driven the car a few hundred kilometres and, even without tuning, the boost in low end torque is definitely noticeable. The sound is earth shatteringly awesome. The best part is that the Corsa Xtremes still don't drone very badly at cruising speed...but they sound deadly at bruising speed when you want them to. All of the joints sealed perfectly on the first attempt and I haven't had any issues with leaks whatsoever. My distaste for leaks is what made the Pfadt product look so appealing.
I will say that, after roughly 300kms, I did get a check engine light for cat inefficiency. I was initially peeved but, after some research, I see that this code is very common with high flow catalytic converters. It sounds like the only fix is to remove the sensors functionality via tuning. Do you agree, Pfadt? Has anyone ever tried to leave the rear O2 sensors functional and simply adjust the sensing thresholds for cat inefficiency? Any suggestions as to what those thresholds should be? I know the rear sensors are purely diagnostic, but we require them to be functional in Ontario to pass emissions testing. Luckily, my car is newer and I won't have to face an e-test for another 5 years. My question is, if everyone knows that the rear O2s won't work with high flow cats, why do manufacturers bother including harness extensions and sensor bungs at all? Why not just physically remove the bulk? Is it to satisfy visual inspections?
I will say that, after roughly 300kms, I did get a check engine light for cat inefficiency. I was initially peeved but, after some research, I see that this code is very common with high flow catalytic converters. It sounds like the only fix is to remove the sensors functionality via tuning. Do you agree, Pfadt? Has anyone ever tried to leave the rear O2 sensors functional and simply adjust the sensing thresholds for cat inefficiency? Any suggestions as to what those thresholds should be? I know the rear sensors are purely diagnostic, but we require them to be functional in Ontario to pass emissions testing. Luckily, my car is newer and I won't have to face an e-test for another 5 years. My question is, if everyone knows that the rear O2s won't work with high flow cats, why do manufacturers bother including harness extensions and sensor bungs at all? Why not just physically remove the bulk? Is it to satisfy visual inspections?
I've read that people have good luck using spark plug anti-foulers to space out the rear 02's to avoid to code. I just turned it off with HP Tuners years ago and all is fine. Your tuner can do this with a few mouse clicks.
Le Mans Master
Joined: Apr 2013
Posts: 5,376
Likes: 1,118
cool! I'm thinking, come Monday, I'm going to take you guys up on that May madness deal...
Thread Starter
Instructor
Joined: Nov 2008
Posts: 153
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From: London Ontario
I realized that I never followed up post tuning. My tuner (Arun @ Dasilva Motorsports) was able to disable the cat inefficiency CEL while still leaving the rear O2 sensors functional so that I can pass Ontario's new OB2-based emissions testing. Perfect. Because I didn't dyno the car before installing the headers, I can't tell you what the gains were...but I can tell you that I'm now amazed by how smooth the power delivery is. There is no peaked-ness anymore--the car just seems to pull like a freight train right off idle. These headers were well worth the money. Everyone should have a set!
Tech Contributor
Joined: Jul 2002
Posts: 14,950
Likes: 264
From: St. Louis, MO
St. Jude Donor '08
I realized that I never followed up post tuning. My tuner (Arun @ Dasilva Motorsports) was able to disable the cat inefficiency CEL while still leaving the rear O2 sensors functional so that I can pass Ontario's new OB2-based emissions testing. Perfect. Because I didn't dyno the car before installing the headers, I can't tell you what the gains were...but I can tell you that I'm now amazed by how smooth the power delivery is. There is no peaked-ness anymore--the car just seems to pull like a freight train right off idle. These headers were well worth the money. Everyone should have a set!
http://forums.corvetteforum.com/c6-t...ast-heads.html
Decided yesterday to overlay all my mods since I've self tuned and dyno'ed each time I did major mods.
I found it interesting and thought I'd share.
See below. Each line represents progressive mods:
1. stock;
2. headers & tune (3.90 gears at same time);
3. G5x3 cam & .040 gaskets (11.4 compression);
4. FAST, and
5. used AFR 205 heads.
What strikes me is how dramatic the gains from headers and a tune were. Combined with the gears, it felt like a different car, and I got a full second + 10 mph in the 1/4 from those mods, from 12.9@108 to 11.8@118. The car was dead nuts reliable at this level.
The second take away is how all the remaining mods really only mattered from 4500 on. Thus I very seldom notice them on the street, only on the track. Not counting the cool sound of the cam.
Mods 3-5 did take off another second and added 10 mph - to 10.8@128. But it cost a lot more and I broke a diff and two transmissions on my way.
This graph shows what I've been saying for while; headers, tune and gears give you by far the best bang for the buck from idle to redline, the remaining mods only matter from 4500 on. Most street driving is below 3000 rpm...you do feel gears and headers even at that level.
Hope someone finds this useful as they decide upon mods.
I found it interesting and thought I'd share.
See below. Each line represents progressive mods:
1. stock;
2. headers & tune (3.90 gears at same time);
3. G5x3 cam & .040 gaskets (11.4 compression);
4. FAST, and
5. used AFR 205 heads.
What strikes me is how dramatic the gains from headers and a tune were. Combined with the gears, it felt like a different car, and I got a full second + 10 mph in the 1/4 from those mods, from 12.9@108 to 11.8@118. The car was dead nuts reliable at this level.
The second take away is how all the remaining mods really only mattered from 4500 on. Thus I very seldom notice them on the street, only on the track. Not counting the cool sound of the cam.
Mods 3-5 did take off another second and added 10 mph - to 10.8@128. But it cost a lot more and I broke a diff and two transmissions on my way.
This graph shows what I've been saying for while; headers, tune and gears give you by far the best bang for the buck from idle to redline, the remaining mods only matter from 4500 on. Most street driving is below 3000 rpm...you do feel gears and headers even at that level.
Hope someone finds this useful as they decide upon mods.
SUBVETTE
Joined: Jul 2006
Posts: 3,841
Likes: 93
From: San Diego CA
Wonderful write-up. Thanks. One additional tip: When I installed my AR Headers solo on jack stands I used ARP studs instead of the stock bolts and it made it super easy to hang the headers from below without a second set of hands.
Cruising
Joined: Dec 2012
Posts: 12
Likes: 0
From: Elma New york
Just installed ,by myself a backyard mechanic,PFADT headers catted x pipe,Hallitech CAI ON MY 2008 BASE 3lt.Had it dyno tuned at Innovative tuning,Buffalo,NY on friday heres the results.I already had B&B prt mufflers on and the car sounds awesome and a definite difference in sotp feel on the street.Headers fit perfect longer o2 extensions were included to route wires out of the way easier and had no check engine light but tuned them out just in case.Bought the parts from BER racing he had the best prices and great service.Could not be happier with the results.
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Le Mans Master
Joined: Apr 2013
Posts: 5,376
Likes: 1,118
When I look at the dyno sheets of vettes with the Pfadt headers, it occurs to me that the tri-y header is exactly what an LS3/L92 headed car or truck needs for street duty, in order to allow scavenging to offset the lack of low speed port velocity from having such large (relatively) intake ports. I remember back in the old days reading articles about the benefits of using Doug Thorley Tri-Y Headers and I think that the 4 into 2 into 1 header design has once again proven itself as the better header design for generating more torque and power 'under the curve', which is what is you feel SOTP. Couple that with outstanding quality and fit and this seems like the obvious choice from a street driven Vette.
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Safety Car
Joined: Dec 2009
Posts: 3,724
Likes: 9
When I look at the dyno sheets of vettes with the Pfadt headers, it occurs to me that the tri-y header is exactly what an LS3/L92 headed car or truck needs for street duty, in order to allow scavenging to offset the lack of low speed port velocity from having such large (relatively) intake ports. I remember back in the old days reading articles about the benefits of using Doug Thorley Tri-Y Headers and I think that the 4 into 2 into 1 header design has once again proven itself as the better header design for generating more torque and power 'under the curve', which is what is you feel SOTP. Couple that with outstanding quality and fit and this seems like the obvious choice from a street driven Vette.
Le Mans Master
Joined: Apr 2013
Posts: 5,376
Likes: 1,118
Yep, it works. Just like with a carb motor how a dual plane intake manifold produces better torque than a single plane. Same effect, just on the other side of the combustion process, so to speak...
Tech Contributor
Joined: Jul 2002
Posts: 14,950
Likes: 264
From: St. Louis, MO
St. Jude Donor '08
Do you have any dyno sheets comparing your headers on a heads/cam LS2 to other 1 7/8 "regular style" headers?
Safety Car
Joined: Dec 2009
Posts: 3,724
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Here is a dyno for cammed application:
Melting Slicks
Joined: Jul 2004
Posts: 2,721
Likes: 149
From: North Carolina
Seriously considering these for my GS. I have what might be a stupid question.
For those running these headers, do you notice more engine noise in the cabin? I had headers on my LT4 and while I liked the exhaust sound, they produced significantly louder engine noise in the cabin. I eventually switched back to the stock manifolds due to the noise.
Appreciate your insights.
For those running these headers, do you notice more engine noise in the cabin? I had headers on my LT4 and while I liked the exhaust sound, they produced significantly louder engine noise in the cabin. I eventually switched back to the stock manifolds due to the noise.
Appreciate your insights.
Thread Starter
Instructor
Joined: Nov 2008
Posts: 153
Likes: 0
From: London Ontario
I hear some more engine noise from the car in general, particularly more valvetrain noise. Across the entire RPM range, the exhaust is definitely louder, too. However, I'm pleasantly surprised that my Corsa exhaust still doesn't really drone on the freeway. Any increased noise that I do hear in the cabin sounds so good that I welcome it!
Thread Starter
Instructor
Joined: Nov 2008
Posts: 153
Likes: 0
From: London Ontario
By the way, if you overlook the fact that I filmed this with my iPhone in portrait orientation (idiotic, I know...), here's how the car sounded during one of the dyno pulls!
Last edited by RestoRoc89; May 23, 2013 at 03:24 AM.
Thread Starter
Instructor
Joined: Nov 2008
Posts: 153
Likes: 0
From: London Ontario
Congrats, CI GS! You're going to love the driving experience that much more in the very near future! Are you planning to do the installation yourself? It makes for a fun weekend project! I've been very tempted on multiple occasions to pick up the MF103...but I know a supercharger is on the horizon, so it seems a wasteful expense.
To second Boboh's earlier recommendation, I also purchased my headers through BER (Bare Essentials Racing). Cajun is a fantastic vendor who I would happily deal with again.
To second Boboh's earlier recommendation, I also purchased my headers through BER (Bare Essentials Racing). Cajun is a fantastic vendor who I would happily deal with again.
Le Mans Master
Joined: Apr 2013
Posts: 5,376
Likes: 1,118
Thanks man. Listening to you and other guys that did this install is what sold me on these headers. I'm ordering them direct from Pfadt and getting the Halltech CAI for $75 off (its their MAYhem deal) so I couldn't turn that deal down. Yes I'm going to do the install myself and will have to use blocks, as I don't have a lift. I will report back on here when I've installed them.
Safety Car
Joined: Dec 2009
Posts: 3,724
Likes: 9
Thanks man. Listening to you and other guys that did this install is what sold me on these headers. I'm ordering them direct from Pfadt and getting the Halltech CAI for $75 off (its their MAYhem deal) so I couldn't turn that deal down. Yes I'm going to do the install myself and will have to use blocks, as I don't have a lift. I will report back on here when I've installed them.
