Shirl

My car has run 13.1 @ 106/105mph all 4 passes a couple weeks ago. It feels as though the exhaust is choked up on the top end. I only have a Blackwing and cold air screens. Otherwise it's bone stock.

How many tenths can I expect from a good catback system such as a Borla? .2? .3? I'd like the car to run at least 12.8.. Thanks!

98vettedave

The catback system (alone) will only give you a net 8 hp max.That equates to a very small improvement in ET.You may see an improvement of .075 or less.

Headers,X-pipe,and the catbacks should be about a 0.3 improvment on a stock motor.With the improved exhaust flow all your additional mods will show a much greater increase in HP/TQ.

chaase

You will get little to no gain from a catback. If you want to run 12.8, get headers, catback and then a tune.

j0n

A catback will give you a nice sound, no performance increase. Do you have an auto or 6 speed? With a 6 speed i'd slap some sticky tires on it and go to town. With an auto do a stall and some sticky tires. In either case you'll be running better than your 12.8 goal with just a little bit of practice.

Edit: For the record I went 12.7 my second time out with nothing but BFG drag radials and a tune(stock intake, exhaust, even the factory air filter!)

Shirl

Nice ET! Where was that at? Island, Atco or Etown? I was running the car at Island a couple weeks ago. I have an Auto.

Thanks for all of the replies. Makes sense. Looks like I need to do the entire exhaust and a tune.

paint it black vette

3.42's gears,3200stall,headers with high flow cats and exhaust. dont forget the sticky tires and a linelock. should be good for 12.4 or better

j0n

Atco, that improved to 12.640 with the same setup(tune, sticky tires only)

Mark-44

I agree with the headers...but I didn't need a tune, or the 3:42.
torque converter (2800) and sticky tires. I use the 17" MT DR's.
.
Just my 2 cents.

chaase

Many combinations will work. I did 12.8x with just a CAI and a tune.

Shirl

I guess a tune makes a considerable difference. Any recommendations on who to go to? Anyone send their PCM out? Or is it better to have it done on-site.. ?

motogib1

The real answer to the original question: How many tenths can you expect from a catback is none.

Tsab

Pretty much right.

If you have the funds.......go with a good quality set of headders and you might want to ditch the blackwing and go with a Vararam which IMHO is a better overall cold air intake, then have it tuned. Should be good for a noticable increase.

chaase

Not sure where Dover is in NJ, but if I lived in NJ, I would go to ECS for a tune. I am lucky enough to have The Vette Doctors nearby to handle all of my work. I would still invest in the headers.

j0n

I would recommend TTP in north jersey: http://www.ttperformance.net/

Matt did my tune and it's 100% spot-on

Shirl

Thanks for the link!

What's everyone's take on cutouts? Maybe cutouts in the stock exhaust before the mufflers? (Not sure if I want to go the whole headers route yet. Maybe next spring or summer.)

j0n

Again, good if you want some noise, but won't give you any HP increase. I would recommend just saving up for the catback of your choice instead of doing the exhaust twice. Personally I have the GHL bullets and they are perfect. Granted, they're a bit expensive compared to other exhausts out there but I think the price is justified for the system.

Shirl

Ok, cool. Thanks for ALLLLL of the help!

nickolbag

Curious, what was your 60' at Island? I bet not good. I was there a few times this fall and the track prep is typically a lot better at Atco or E-town. Hit Atco this fall and I bet you see a nice improvement in ET. The Atco mod is definitly a lot better than a catback

If you are looking for a tune there is also Cartek in Garwood. I have been using them for years. Julio is the mand when if comes to tuning LS engines.

MPM IV

You might consider the Z06 Ti cat back to shed a few lbs.

Shirl

I never raced at Atco. Always E-town or Island. Island is a LOT closer for me. I was pulling 1.9 60fts at Island a few weeks ago. I thought that was decent, but I was trying real hard for 1.8's. Tires stuck pretty well with very minimal spin, but maybe some nice DR's or ET Streets would get me the 1.8 or like you said: ATCO.

Do you know how much Cartek charges for a tune? What program do they use? (thanks..)