Have seen numerous posts over the last year of so about The "No Respect" mods. You know those dual cone CAI and various catbacks.
"Not worth installing, except of the sound" says one "expert". Those dual cone CAIs look nice but, Don't expect any HP 'cause of to much turbulance" posts another "expert".
Well, Corvette Fever is moding and dynoing a C5. The dual cone dynoed an extra 12 RWHP and 14 ft-lbs of torque. Then the catback added 7.65 RWHP and 1.34. TOTAL for the two 19.94 RWHP and 15.08 lb-ft of torque. No tune. Work done at Next Level Performance on a new Dynojet. I was surprised! You?

 

very much but its good news

 

Works for me

 

Not me, it will take alot more research to convince me .

 

Take a pic or scan the dyno sheets and add to your post. That will put the matter to bed once and for all.

 

CAN'T...Won't be back for a day or so

Anybody have a mag?

 

Here's a magazine article from 'Vette magazine. They gained 31 rwhp from a X-pipe, cat back and a canned tuned.

http://vette.automotive.com/61345/ve...on-tuning.html

Here's a dyno of cat backs and shorty headers, also from Vette Magazine...

http://www.vetteweb.com/tech/0501vet...ust/index.html

Note that the cat back alone does gain, 14 hp. However, that's at 5,600 rpm. The gains up to 4000 rpm are only 7 hp and 8 lbs ft of torque, so seat of the pants may not detect any improvement. If I'm accelerating from idle, you definitely won't feel the extra 3 hp that it produces down low.

Now, stacking mods may have a different effect as in the first article. It looks like one or two of these mods doesn't do much. Intake, x pipe, cat back and tune probably do add some good power.

The only problem is...

Intake: $300
X Pipe: $250
Cat Back: $800
Tune: $350

Total cost about $1700, maybe 30 rwhp if the article is to be believed

Long Tube Headers with catted x pipe: $1500
Tune: $350

Total cost $1850, 40 rwhp if not more.

That said, I'm going with the simple bolt ons.

I don't want to modify the pollution controls on the car and don't want any problems down the road with O2 sensors, throwing codes, etc. That eliminates long tube headers. Gears are out, since I don't want my mileage to drop 10% (great mod, though, I've had it done on other cars). Force induction is out because of cost and potential reliability issues.

The more radical your bolt ons the more your resale value suffers. Most people are not looking for a car with radical mods. In fact, many assume that it's been driven hard by it's owner if it's had too much done to it. I'm planning on selling my C5 after I drive it a few years and upgrading to a C6. That means simple bolt ons for me!

 

Well I believe it,,While I had no baseline runs without,I had, IMO, fantastic dyno results on my car.I have a 2000 FRC that is stock.From front to rear it has a blackwing intake,stock motor ,cats,stock H pipe and Corsa Touring cat back. The Valvoline "Dyno Go" display (the one that has a thread looking for Chicago area Vets now) used my car for dyno runs while in St.Louis. They did a first series of three pulls ,then 5 more sets of 2 each.The ECM learned and adjusted air/fuel and such and the #s went from a low on first set of 323.51hp/324.76tq--- to 338.92hp/345.91tq on the last pull. This is on a stock set up except for air filter set and cat back. Took it to the same track the following Tuesday for the first time,made 5 passes and did13.43,,13.61,,13.64,,13.40,,and13.08. Again same set up on stock GY run flats. Two weeks later Did a 240 mile round trip with about 12 mi city and averaged 28.73 calculated actual mpg.No intake and exhaust don't give you tons of HP &TQ,,but they don't hurt either!!

 

Not true. There can be a small % of fluctuation from dyno run to dyno run. Even 2% of 300 is 6 HP. I read the article and I am sure there is some HP to be gained by the mods, but when dealing with these small increases, they can be influenced by the dyno itself.

 

A certain amount of truth there. As in my case the computer learns you are running W O T and adjusts for that running condition and adjusts air/fuel ratio (it was visible on the graphs and print out #s ) over 13 pulls it picked up 15.4 HP,,,,Just doing dyno runs can pick things up on a stocker!!

 

Not true. There will always be people to downplay and discount any gains these mods have no matter how many dyno sheets are posted.

See?

I'm just messing with you, I know the dyno can fluctuate. Significant performance gains won't come from simple bolt ons (LT/tune excluded). But every little bit helps. I know a port/polished TB won't give me any noticable horsepower, but it's better than no improvement at all and I want one anyway.

 

Ditto That!

Our car has been on the dyno so many times over the years, that I should have a plate on the unit that says, "Partially paid for by Sully." At times, we have run 3-4 dynos back-to-back and the fluccuations were as high as 8-10 hp from lowest to highest. Trust me...cat-back is for sound...the exhaust system past the cats is NOT restrictive.

Remember, the value of a dyno is as a tool to tune the engine and determine the power curve of the car, unless the objective is just bragging rites. Also, keep in mind that peak HP numbers are not as important as the total area under the power curve. That is really what counts as your total power band. Our tuner actually lowered the peak HP of our 427, widen the TQ & HP curve and the car was noticeably faster at the track.

Our original stock LS1 was the first in the country to be re-tuned (what a mess that was!) and we picked-up ~15-20 RWHP, depending on which dyno result I use, just by adjusting GM's settings. For guys with an A4, the other advantage is using the information from dyno to set shifts points to the respective peaks and adjust TQ management / TC lock points. Adjusting these will provide better performance!

 

Wonderful, this issue will be debated until the apocalypse!

 

Any CIA should be better than the stocker and a plus is that the Dual Cones look good too!

Great info and thanks for sharing

Thanks,Matt

 

 

We need the before and after Dyno sheets for proof and I bet it did pick up some HP though

 

Still without a scanner..but FYI
Base @ 295.55 HP 305.20 Torgue
Filter @ 307.84 HP 319.94 Torque Increase across entire band
+Exhaust @ 315.49 321.28 Torque Increase above 4200

Just the messenger....