Exhaust

[RoyWoods]

I have a stock, black 2001 Cobra (#130 of 3867). The one "mod" is 6 coats of Zaino. What are the best "bang for the buck" modifications that I can do, and how much hp should I gain from each? I'm thinking of a Bassani or Magnaflow X-Pipe with Bassani/Magnaflow catbacks, but wanted opinions. Thanks.

[Ken 01-Cobra]

I have Before and After dyno's of some of the more common bolt-on's on my site. You can reach it by clicking the link in the sig. That will give you some idea in real, RWHP/RWTQ numbers what things are actually worth on my car. YMMV...

Good luck with the mods! ;) Once you start, you're doomed!

[guitartate]

Thanks for the documentation on your website. I also was very curious about what will make the most difference. I just put in a K&N filter but will probably switch to the K&N FIPK.

[Ken 01-Cobra]

Originally posted by guitartate
Thanks for the documentation on your website. I also was very curious about what will make the most difference. I just put in a K&N filter but will probably switch to the K&N FIPK.
The C&L MAF was the single largest bang for the buck for me. :) It comes with a conical K&N.

[mach0ne351]

gears
bassani xpipe
bassani catback
densecharger cai

:)

-marek

[Lumpydogs]

Regarding the Magnaflow Catbacks...
I read two different articles that said basically the same thing.
On the '01 Cobra you can increase torque and HP by changing to high performance mufflers. New high performance cat back
systems increased torque and HP no more than mufflers alone.
According to the articles the main exhaust restriction on the '01 is the exhaust pipe taper leading into the stock mufflers. A Muffler shop will cut out this tapered section when welding in new mufflers thus removing the restriction.

I went with the Magnaflow mufflers alone. Everyday driving is
very slightly louder but WOT has an aggressive sound and is
much louder. Power feels better (no dyno numbers). Only con
is a mild drone inside the car at 2,000 RPM.

That's my two cents

[Ken 01-Cobra]

Originally posted by Lumpydogs
Regarding the Magnaflow Catbacks...
I read two different articles that said basically the same thing.
On the '01 Cobra you can increase torque and HP by changing to high performance mufflers. New high performance cat back
systems increased torque and HP no more than mufflers alone.
According to the articles the main exhaust restriction on the '01 is the exhaust pipe taper leading into the stock mufflers. A Muffler shop will cut out this tapered section when welding in new mufflers thus removing the restriction.

Ummm, I disagree. I had just mufflers on mine before the X-pipe and catback, and I definitely picked up HP AND torque going to the X-pipe and catback! The stock pipe is 2.25" Going with 2.5" WILL increase the exhaust flow! As always, YMMV...

[SNKBYTT]

I went with the MagnaFlows and the sound is great. Unfortunitly I can't back up any numbers because I never had a before Dyno. I'm hoping to find out this summer.

[Skip Miner]

Regarding exhaust fixes, I'm with Ken on this. I dyno'd at 280rwhp and 279rwtq with the factory exhaust. Then I changed to a Dynomax X-pipe w/ cats and catback. My latest dyno was 297rwhp and 297rwtq. You can probably get the same relative numbers from any good straight through mufflers -- the exception being Flomaster. It is a chambered muffler and allows you to vary the sound but is a bit more restrictive. Also, most of the aftermarket x-pipes have only 2 cats vice the 4 on the stock h-pipe. Finally, most have mandrel bends w/ 2.5" pipes versus the stock 2.25" pipes.

Also, Ken is right -- once you start you're doomed.

Skip Miner
99 White Vert
Mac CAI, Superchip, Dynomax X-pipe w/ Cats and cat back,
Pro 5.0 short shifter, Kenny Brown Club sport suspension w/ Bilsteins, SS brake lines, Hawk HPS pads (about to upgrade to Hawk HP Plus pads), all urethane bushings, including IRS frame bushings(that was a job!), 6 pt autopower roll bar, 3:73 gears

[Ken 01-Cobra]

Hey Skip...haven't heard from you in a while! How are things?

The latest mod on my Cobra are 2003 half-shafts. NOW I can launch the beastie I hope! ;) Will be going to the track any day now to check out the gains.
:bna :D :bna

[Skip Miner]

Ken,
Doing great. Had three days at Summit Point in March. Got my best speed in the front straight -- 130 mph. Still shooting to get to 140 mph before I have to get on the binders at turn 1. After 7 track days at SP I've pretty much used up my brakes. I'm replacing the rotors, pads and flushing the system before my next track outing -- hopefully in May.

On Mar 7th on the last lap of the last session I finally had my first spin out. If you look at the track diagram for SP I was pushing 90 mph through the fastest turn (4) on the track then getting on the binders for the slowest turn (5) on the track leading into the carosel. Unfortunately, I was paying too much attention to the Porsche in my rear view mirror and was late on the brakes. I thought I had saved it coming out of the turn when my right rear tire caught some mud and snow on the edge of the track. Next thing I know I'm in a snow bank. Happened really fast! Fortunately, no damage and a good lesson learned. Also, the strut tower brace is a good place for the tow truck to hook up to when being pulled out of a snow bank. Need to get back on that horse again, soon. With the war and all, I haven't had a chance in April.

I'm flying to Atlanta with my youngest daughter and wife this week-end to see my two older daughters and grandsons. I'll call you.

BTW, I put the H&R rear spacers back on. I don't think they cause the IRS to rear-steer any more than normal, but I think they give me a better feel for when the back end starts to step out in turns. Might have given me more warning when I got into that spin. Adding the urethane IRS frame bushings seems to firm up the ride and stabilize the IRS.

Skip Miner
99 White Vert (52K miles)
Mac CAI, Superchip, Dynomax X-pipe w/ Cats and cat back,
Pro 5.0 short shifter, Kenny Brown Club sport suspension w/ Bilsteins, H&R 1" spacers (rear), 255x45x17 Kumos all around, SS brake lines, Hawk HPS pads (about to upgrade to Hawk HP Plus pads), all urethane bushings, including IRS frame bushings (that was a job!), 6 pt autopower roll bar, 3:73 gears.

It's been awhile. Guess I have to modify my sig.

[Ken 01-Cobra]

Man...sounds like you are really getting some track time with your Snake! I seem to recall someone saying that if you are not spinning out once in a while, you're not pushing it hard enough. ;) Just don't make a habit of it.

If you call, call my cell if it is not raining. I will probably be at the track testing the new wheel/tire combo. Drop me an email if you don't have my cell and I'll give it to you. :D I am really looking forward to this test session!

[99_Venom]

Well I'm going to throw in a little teaser here. The best mod I have done to date is putting in a T56 from D&D Performance. The closer ratio of the gears allows me to have good pull at just about any speed. Even the shift from 4th to 5th is not a big drop in rpm. I find that I can go from a roll at just about any speed and it is just right there. So if you like to drag and do open track you can stuff the gears in and still go play on the open track. All I can say about this mod is WOW.
You can look at my sig for the list of other mods. I haven't been to the dyno lately but my 103.35 trap speed at 3705 lbs (with me in it) shows about 318 hp to the wheels and I haven't even got to adding headers yet. I had it weighed at the track on the return lane right after the run so I could have an accurate weight for the measurement.
By the way that was the last run before I put in the T56, broke the T45 for the last time on the next run.

[Ken 01-Cobra]

Yeah...I had thought about the T56 myself...but they are like 125 lbs heavier than the 3560, right? The 4.30 gears could use that extra OD gear on the highway for sure, but you probably weigh over 3800 now with the T56 in it. Mine is 3660 with 1/2 tank of gas, me, spare, jack, trunk carpet and board and floor mats removed. I just got 15" Centerline Autodrags and MT ET Streets to replace the Steeda Ultralites and Nittos for the back, which should save another 12 lbs, and if I use up another 1/4 tank of gas, that would save another 25 lbs, getting her down to about 3625 lbs.

[99_Venom]

The Viper T56 is heavier but the standard T56 is close to the same, maybe 20 lbs heavier. I didn't go with the Viper T56 for that reason and also you will need to have the exhaust modified for the Viper T56, it's big. The standard T56 has better gear ratios for the NA car also. Just going from the .67 5th of the 5speed to the .62 6th of the 6speed made a big difference in cruising speeds with the 4.10s. I think I am going to either put the 4.30s back in or order a set of 4.56s and try those. I might just as well one of each of the gears sets on hand LOL. Here is a list of the ratios for the different trannys:

The 99 T45 has:
1st 3.37
2nd 1.99
3rd 1.33
4th 1.00
5th 0.67

The Standard D&D T56 has the following ratios:
2.97 1st
2.07 2nd
1.43 3rd
1.00 4th
0.80 5th
0.62 6th

The Viper T56 has:
2.66 1st
1.78 2nd
1.30 3rd
1.00 4th
0.74 5th
0.50 6th

The 03 Cobra T56 has:
2.66 1st
1.78 2nd
1.30 3rd
1.00 4th
0.80 5th
0.63 6th

[Ken 01-Cobra]

Ah...I did not know that about the weight. Thanks for the heads up!

The stock 3560 is:

1st: 3.37
2nd: 1.99
3rd: 1.33
4th: 1.00
5th: 0.67

First is a bit quick with 4.30's! The gearing in your T56 would probably give you more than a blink in 1st with the 4.30's. I am not sure that the difference between .67 and .63 is going to make a lot of difference in the RPM's at cruise speeds though. The .50 would make a definite difference! :haha:

[99_Venom]

Ya I really wanted that .50 6th but it only comes in the Viper T56 for the Mustang right now. So it seems as though there is alway a comprmise. If you want I made up a spreadsheet with all the different speeds and rpms with the 6speed. I also have a line to compare the .67 5th to the .62 6th. Send me an email at tennant@cox.net and I will send it to you.

[Ken 01-Cobra]

I wonder what would be required to change out the 6th gear in yours to the 6th in the Viper tranny? If it were simply a matter of dropping in another gear, it might be worth the price! That .50 would be really sweet for the 4.30's in that you would have the full performance at the track but could still cruise at ~2400 RPM (guessing) on the Interstate. (yes, I tend to cruise a bit fast on the highways! ;) )

[99_Venom]

Joe at D&D talked like the .50 6th was only available in the Viper tranny. I asked him if he could swap out the .50 in the standard T56 and he said no. Sure would be nice though.

[Ken 01-Cobra]

Thanks for the spreadsheet. It looked to be pretty close to what I've observed with my 4.30's. Based on that, the savings aren't all that great over the 3560.

Hmmm, I wonder WHY the .50 couldn't just be dropped in? I wouldn't think they totally reworked the tranny to put 1 gear in it! Ah well...I ain't a tranny guru, so I wouldn't know. It just seems strange based on what I know about how manual trannys work that the gear would be all that different. Of course, what I DON'T know is way more than I know! ;)