ExcessKuma said:
Good evening fellow GRM members, I' m diving into a topic I have absolutely no experience in and figured the best people to ask would be a forum full of master fabricators and machinists. I have been dailying the ex 2015 (16?) Q45 Challenge car for the last year...
In 2014 I entered the first Q45, a 1991, which developed more than a tick and less than a knock in the drags. I sold the car in Gainesville and drove home a rental. In the following months, I bought the identical color car but this time a 1990 with hail damage but only 68k miles.
1991 car
1990 car
https://grassrootsmotorsports.com/forum/grm/aristocrat-class-luxo-barges-overwhelm-the-2015-ch/105027/page1/
...and while overall it's been a fantastic car, it has one small issue. Early on to it's ownership, it had a late night date with a sawzall and has been straight headers for a while now.
In my ownership there was no sawzall. I simply unbolted the rear muffler section. This then left two cats, two resonators and then the pipes ended at about the rear axle. The part taken off was where two pipes join as one and then enter into a "gentlemanly quite" muffler. This muffler is rectangular and about the size of carry on luggage. I think I remeber that it weighed 60 lbs.
While I didn't think the performance decreased much, I was shocked to find at the local test n tune that I was running high 16's, nearly 2 seconds slower then it ran in the challenge a few years prior.
I seem to remember not getting into 14's but 15.0 and 15.1 drag times I do remember.
At the 57 minute mark of this video you can see the car being introduced at Roadkill Hooptie Zip Tie Drags but sadly no actual race video. The competition was blind parings and the Q45 won 3 races.
While I'm not looking to do a full exhaust replacement, I am looking for suggestions on what to run to gain back some losses. Currently what remains of the exhaust is roughly a foot past the end of the headers with my original goal being running either twin 12inch/18inch mufflers with a downturn at the end to create some restriction.
All help greatly appreciated,
Kuma
I took this video for sound just after unbolting the rear muffler. Near the differential you can still see that the bolt flanges are still there where the rear section was unbolted. The rear muffler went to Pat. I'm not sure if the rear muffler made it to you. It was complete and could have been re-bolted back on.
This is what the suitcase sized muffler for a Gen1 Q45 looks like:
This would reside in the rear-most driver's side.
So, going forward... the original is two pipes down the center that shortly after the rear axle then combine into one large muffler that resides on the driver's side. I recommend replicating that set up as much as possible.
Cats:
Resonators (mid mufflers):
Suitcase muffler (notice the angle on the tips, you are seeing the bottom of the muffler):
