wake

It took several hours to install because of fitment problemes with the rear pipes, but I got the Force II system installed this afternoon and let me tell you, this is one sweet sounding system...

It has a nice rumble at idle and is quite a bit louder at WOT than stock but not overpowering... And the best part, NO RESONANCE!!!

Other than the problems with fitment, I'd say it's the best system for the money... It was a PITA to install because I ended up having to fit the rear parts on several times before I could get them lined up right... And to get ther left rear muffler tips to line up with the right, I had to fit the system together and then jack the exhaust up by the pipe, slightly bending/reshaping it before I got it right...

The only remaining thing is to have an exhaust shop reform the rear pipes again to clear the diff... Currently it is slightly touching my differential and as a temporary fix I put some firesleving as padding between the diff and the pipes... It had to go to the exhaust shop anyway as I'd rather have the system welded together than clamped...

Back to the sound... This system really is an improvement over the complaints I've heard about the old American Thunder line... There is absolutely no resonance anywhere through the RPM range with the Force II and it reminds me of my F-Bodies with the Flowmaster cat-back, with one exception... When I decellerate in gear, the exhaust just rumbles... It doesn't pop like I've experienced with my F-bodies... Flowmaster did an excellent job with this system... :thumbs:

65Z01

Congrats on a good soundiing Vette. :cheers:

I wonder how the Force II is on a L98, as we have a single exhaust system with no resonators.


[Modified by 65Z01, 3:20 AM 5/1/2004]

IMXCITD

:thumbs:

corvettemaster

:iagree: i'd like to know this too.

got any sound clips? :D

carson

I put a force 2 system for a LT1 on a 90 L98 last year and am very happy with it. With stock exhaust manifolds and no cats, I do not have a resonance problem.

Last week I made a 4 hour trip and tire noise was louder than the exhaust in 6th gear at 65 to 70 (used to be my resonance peak). With the stock exhaust system I used to carry earplugs for a long trip, not any more.

Sounded so great under acceleration and deceleration when I first got it on I was speeding up and slowing down just to hear it.

I also had the problem of getting the muffler tips lined up straight but I got it close enough for me. The end of the tips could also be cut more even and straight, those are my only complaints. No clearance problem with the rear diff here.

I needed to change 4 bolts on the rear end to bolts with studs to hang the LT1 rear exhaust hangers. The front LT1 hanger bolted to existing holes.

When it was colder I used to get a code 32 occasionally, but since it is warmer I have not had the trouble code show. I also put in a heated O2 sensor for the reduced backpressure, but checking with a scan tool it still got hot enough to go into closed loop idling without voltage heating it.

-=Jeff=-

I had the Force II on my stock 89 L98 with no Pre-cats and a PFP main Cat (Mid America $150 one) There was a minimum of resonance. I was nice sounding.

Now if you have Long Tube Headers it won't help too much, but some. I have Long tubes with a ZR1 Borla aexhaust , No cats and the resonance is minimal as well


[Modified by -=Jeff=-, 12:35 PM 5/1/2004]

Bruthish

:cheers: :thumbs: :thumbs:

CanadaVette

I want to do mine also someday

Vett-eight-nine

Sorry but "Now if you have Long Tube Headers it won't help too much, but some. "
What won't help too much, Jeff? The Force II cutting down on resonance?
Thanks. :)

1990dtgL98

I have the 50 series (aka- Force II) on my 1990 L98 with stock all the way around exhasut except for a gutted main cat. It sounds mean at idle (not loud, maybe a little more than normal conversation, but very deep tone) and stellar at WOT (loud and deep, perfect combo!)

Moto64g

I put the FM system on my 94 and I'm really happy with it. I also had the same fitment problems that you did. I'm still riding around with a spacer between my rear dif and the
exhaust system.

Yellow Fever

I know the feeling bud. I just had Midas build me a brand new system. (my son works there) The were able to get a full dual system from front to back, using hi flo cats and performance Ravens. They even put an "X" pipe in the mix. What a difference in the sound and performance.

wake

Hmmmm, Interesting... I guess it's a design flaw then and not just a bad part... It's a simple piece so I figure it shouldn't cost too much to have a muffler shop build me a new one that doesn't interfere... I'm not too crazy about the pipes being so close to the diff... I'm sure that's not good for the diff lube... Thanks for the info, maybe I should send some info and pictures to Flowmaster... I wonder if they'd do anything about it...

86PACER

My Force II y-pipe also comes really close to the differential. I managed to keep about 1/8" clearance between the differential and the y-pipe after everything was tightened down.