LS3 CAM AND HEADERS DYNO

[radz28]

Originally Posted by dieseldave24v

Yes. There is a federal emissions law, then states decide how they are going to check it. Some "ie California" are very strict. Others just kind of go through the motions. I dont think there will ever be a set of CARB legal LT headers.

I don't agree with the rules, but they state the the factory catalytic converter(s) must remain intact and in the factory position(s). The converter are so far forward on most cars that there isn't room for long tube without breaking that rule.
The reason the rule exists is so that cold-start catalyst light-off is not delayed by the additional exhaust tubing length between the heads and converters. Also, the oxygen sensor has to be in the flow post-collector. Long tube headers require that the sensor be moved further downstream since the collector is further downstream. The further from the head ports the oxygen sensor get the more "lazy" they get since they're measuring the output from operating conditions "too old". Basically you end up with bad data and that affects emissions too.
So, YES - long tube headers absolutely fail visual inspection by definition.
Long tube headers themselves have minimal effect on actual emissions, the problem is the latency induced by the greater exhaust gas travel to the O2 sensors. Generally, they WILL pass the sniffer because there is very little affect at constant sustained throttle conditions where these test take place at on t he dyno.
Of course, legal headers must acommodate all factory emissions eguipment like EGR, A.I.R., O2 sensors, etc.

I measured exhaust temperatures on the primaries right off the exhaust ports and compared to temperatures at the inlet to the cats', and there was a significant difference in temperatures. To my understanding, this entire post is great information (not that it needed validation from me). I imagine coatings and tube thickness will play factors in retaining heat in the header tubes and transfer them into the cats' but those babies have to be pretty hot in order to burn off combustion by-products.

Great post

[rgrizzard]

At this point I would like to see numbers with stock manifold vs. GMPP shorty headers vs. LT's. Before I change the manifold out.

[POWERFREAK]

Originally Posted by rgrizzard

At this point I would like to see numbers with stock manifold vs. GMPP shorty headers vs. LT's. Before I change the manifold out.

For the $1000 price tag on the shorties, I think it's safe to say they're not worth it.

[UCF w00t]

Originally Posted by kevin2323

kk down here in miami....never heard of it...thanks for the info/

That's because florida doesn't do any sort of emissions or safety checks on cars. Another reason why florida is the greatest state in the union. As long as you live in florida, you could put whatever mod you want on your car with no trouble unless your exhaust gets too loud a cop can right you a ticket. If that happens you can just pay the ticket (I want to say it's like $20) and keep on driving with the "illegal" exhaust.

[MerF]

Why is your graph measured in speed instead of RPM though? Don't tell me you didn't measure engine speed for a dyno run!

[SoFlaZ]

Originally Posted by UCF w00t

That's because florida doesn't do any sort of emissions or safety checks on cars. Another reason why florida is the greatest state in the union. As long as you live in florida, you could put whatever mod you want on your car with no trouble unless your exhaust gets too loud a cop can right you a ticket. If that happens you can just pay the ticket (I want to say it's like $20) and keep on driving with the "illegal" exhaust.

<3 Florida

[dieseldave24v]

Not to go to far of topic, but I do have to say that think Florida is the best state in the union. Especially on working on your car as mentioned. We used to have the drive up smog sniffer once a year. They took that away years ago. I haven't lived there in 6 years, but all my vehicles are still registered there just for this reason.

[ADM PERFORMANCE]

Originally Posted by MerF

Why is your graph measured in speed instead of RPM though? Don't tell me you didn't measure engine speed for a dyno run!

On a Dynojet 248c(and many others) you can print or show many methods of power versus speed,tiime,rpm etc.Just happened to be the way it was printed at the time.

If need be I can print it with rpm,same difference though.

[UCF w00t]

Originally Posted by UCF w00t

a cop can rightyou a ticket.

Wow... what an idiot.

[Mr Twisty]

Originally Posted by UCF w00t

Wow... what an idiot.

You oughta kick his arse!

[camaro5]

Originally Posted by UCF w00t

That's because florida doesn't do any sort of emissions or safety checks on cars. Another reason why florida is the greatest state in the union. As long as you live in florida, you could put whatever mod you want on your car with no trouble unless your exhaust gets too loud a cop can right you a ticket. If that happens you can just pay the ticket (I want to say it's like $20) and keep on driving with the "illegal" exhaust.

Originally Posted by SoFlaZ

<3 Florida

Originally Posted by dieseldave24v

Not to go to far of topic, but I do have to say that think Florida is the best state in the union. Especially on working on your car as mentioned. We used to have the drive up smog sniffer once a year. They took that away years ago. I haven't lived there in 6 years, but all my vehicles are still registered there just for this reason.

Originally Posted by UCF w00t

Wow... what an idiot.

Originally Posted by MisterCamaro69

You oughta kick his arse!

[LS3SSRS]

well, well, looks like you have yourself a customer. 420hp to the wheels is nice! i dont think ill swap cams, but tune(not on my stock ECM... ill get a different one and swap for warranty work), headers, exhaust, and a cold air intake sounds good to me.

[MerF]

Originally Posted by ADM PERFORMANCE

On a Dynojet 248c(and many others) you can print or show many methods of power versus speed,tiime,rpm etc.Just happened to be the way it was printed at the time.

If need be I can print it with rpm,same difference though.

It is a more comfortable view for me, feels more personal...lol

And as for the Florida OT discussion...hell yeah. I grew up here, then spent 9years in Virginia...also known as the Communistwealth. I am SO glad to be back down here.

[ADM PERFORMANCE]

Originally Posted by LS3SSRS

well, well, looks like you have yourself a customer. 420hp to the wheels is nice! i dont think ill swap cams, but tune(not on my stock ECM... ill get a different one and swap for warranty work), headers, exhaust, and a cold air intake sounds good to me.

We currently have ECM'S in stock for the 2010 Camaro.We are just waiting on vin numbers to start popping up,then we will have in house dyno proven calibrations ready for you guys.

We generally get anywere from 12-30 rwhp with just tuning.


Andy