Turning in my man card... I want to make the GTRA quieter... best method?

[Cobra4B]

Good info posted... I'm going with the same spring setup 550s front and 350s rear and fresh Konis. I went ahead and got a rear bar because the car pushes like a pig for me at VIR running on Nitto R2s which are a DOT R compound with full tread. I'm not "racing" so I wanted a tire that would last all year for our driving events.

My car scrapes the chassis going through hogs pen at VIR so I know it's sprung too softly. For those that don't know Hog's Pen is the last turn before the front straight. It's a long hard right hander w/ a double apex taken at speeds of 70-90ish mph depending on the car you have.

[Craig245]

I also swapped the front 350# springs to the rear and replaced them with new 500# springs. Keeping in mind that sway bars are used to adjust roll stiffness, which is the major tuning adjustment for balance. If it understeers, soften the front roll, and/or stiffen the rear roll. For oversteering, stiffen the front roll, and/or soften the rear roll. This can be easily done with the sway bars but changing the spring rates will also make a big difference. I didn't want the complexity of the rear bar, as I believe the more adjustment that you have, the more likely they will be out of adjustment. When the factory put 550# on the front, I figured that it was too stiff and that is one reason that they added the rear bar...too siffen up the rear. So I chose the 500# in the hopes that it would soften the front enough that the front sway bar adjustment would be suficient to optain a nuetral balance. It worked well. I put on Nitto 555srII's and went to the track. It skated quite a bit but after a few laps I was able to read the tread wear and realigned the front end and reduced tire pressure. The next time out I was very pleased with the balance, and the car turned 130 at Willow Springs, without a usefull 5th gear. (I do have a 347 with 385 RWHP.) This was at a Viper Days and that time was fasteer than 95% of all the Vipers. They called me "That damn Panoz!". After that trip to Willow Springs I replaced the 3550 w/0.69 overdrive withe a TKO600 close ratio w/ 0.82 over drive and also replaced the rear end with a 3.70 I had lying around. This last weekend the car was a dream.

[Cobra4B]

^ I know all year I've had my front bar on the stiffer setting and no rear bar. I'm going to do the new springs and fresh shocks and put the rear bar in a middle setting to go w/ the front bar on stiff, see what happens and adjust from there.

I was wondering how the gearing would work out w/ more power in the car. I guess 5th is still a slug? How much is a TKO 600? What's the current ring/pinion gearing in these cars stock?

[Craig245]

Originally Posted by Cobra4B

^ I know all year I've had my front bar on the stiffer setting and no rear bar. I'm going to do the new springs and fresh shocks and put the rear bar in a middle setting to go w/ the front bar on stiff, see what happens and adjust from there.

I was wondering how the gearing would work out w/ more power in the car. I guess 5th is still a slug? How much is a TKO 600? What's the current ring/pinion gearing in these cars stock?

Stock gearing is 5.50. And 5th is still a slug with 385 RWHP. The car would not accelerate after the shift up to 5th. The TKO from Summit was $1900 or so. It bolted in with no problem except that the input shaft is 26 spline instead of the normal Ford 10 spline. I had to replace the clutch. The TKO is also good for 600 ft-lbs of torque so it should be plenty good for just about whatever you put in the car. The original 3550 is only good to 350 ft-lbs, so it is very marginal for a anything over 350 hp.

[Craig245]

Originally Posted by Cobra4B

^ I know all year I've had my front bar on the stiffer setting and no rear bar. I'm going to do the new springs and fresh shocks and put the rear bar in a middle setting to go w/ the front bar on stiff, see what happens and adjust from there.

I was wondering how the gearing would work out w/ more power in the car. I guess 5th is still a slug? How much is a TKO 600? What's the current ring/pinion gearing in these cars stock?

Stock gearing is 3.50. And 5th is still a slug with 385 RWHP. The car would not accelerate after the shift up to 5th. The TKO from Summit was $1900 or so. It bolted in with no problem except that the input shaft is 26 spline instead of the normal Ford 10 spline. I had to replace the clutch. The TKO is also good for 600 ft-lbs of torque so it should be plenty good for just about whatever you put in the car. The original 3550 is only good to 350 ft-lbs, so it is very marginal for a anything over 350 hp.

[Cobra4B]

What kind of clutch did you put in it? Stock flywheel or move to aluminum?

[Craig245]

Originally Posted by Cobra4B

^ I know all year I've had my front bar on the stiffer setting and no rear bar. I'm going to do the new springs and fresh shocks and put the rear bar in a middle setting to go w/ the front bar on stiff, see what happens and adjust from there.

In an earlier post you said that the car pushed (understeered) badly. If that is true you should soften the stiffness of the front. This will keep the inside tire more firmly planted and help the car to turn.

[Craig245]

Originally Posted by Cobra4B

What kind of clutch did you put in it? Stock flywheel or move to aluminum?

Since this is an open track practice car, I used the steel flywheel that came with the crate engine, and a centerforce Dual Friction clutch. I have used this clutch on several 500+ hp cars and never had a problem.

[Cobra4B]

Yes... but I want minimal body roll. I think the shock/spring change w/ the addition of the rear bar will even the car out and make it neutral. If it still pushes then I'd go ahead and soften up the front bar.

[panozracing]

here is the link to the album I put up showing the hood pins, the light bar (3 years ago), and the exhaust/mufflers......

http://cid-9b2fd8e49c8fec7b.spaces.l...49C8FEC7B!124/

for those talking about a tranny's....Walt at Promotion powertrain is a magician with Tremec stuff....he made a TKO2 (3550) as strong as a TKO600 and we ran both tranny's up over 500 ft.lbs without any issues. He also upgrades the shift forks and some other stuff I never wrote down. He is well known in the drag worlds and knows his stuff....STRONG is his motto....

http://www.promotionpowertrain.com/

[Cobra4B]

^ Wonder if it'd be ceaper to have the 3550 rebuilt and the 5th gear changed out.

[panozracing]

Originally Posted by Cobra4B

^ Wonder if it'd be ceaper to have the 3550 rebuilt and the 5th gear changed out.

I spent around 1k when I broke my 3550 and had the main shaft replaced with the new models main shaft but not the exact same as the TKO600RR's that we have but made from the same new harder alloys. He then changed shifting forks and misc. other stuff. We didnt do any gear changes and the 3550 has slightly diff. 1st and 3rd gears (I think those are the gears and for some reason I think they are a little taller gear ratio but cant remember). I also cant remember how bad the tranny was to tell you if the 1k went to other parts. I know when we break stuff its usually destroyed. Racing is rough....hehe

Pro Motion will know but they are a little quirky...tell them its Brian and Dan with the 2 panoz and the customer is Milestone MotorWorx and they should have the rebuild info in the computer.

[Wess-RA]

Just replaced my "cherry bombs" with a Magnaflow. The new sound is great. Here's a shot of the inside of the cherry bomb. The separation is where someone (previous to me) must have jacked the car up under the exhaust and caved it in against the jacking tube. Bad restriction!

Just look at those porcupine spines.

Here is the Magnaflow-It fit nicely in front of the jacking bar. I rotated it slightly to get the cleanest run.




Here is the Supertrapp which I need to meet Laguna Seca's 91Db requirement. (on weekdays). It looks a bit hokey but it is easily removable (exhaust clamp) when I drive all the other tracks. I used the 5" disks with a heat shield to keep from burning the side plastics. This really quites the car down compared to only the Magnaflows which seems to be running around 110Db.

[Craig245]

Good info on the magnaflow and supetrap. I'm ordered a pair of super turbo magnaflows last week and the supertraps. I want to meet the 91db for a green flag event next month. So...did yours pass that limit? How many discs did you use and which magnaflow?

Craig

[Cobra4B]

Which PN on the magnaflow is that? Craig, which exact mufflers did you go with?