Dyno numbers and a question...

o0Dan0o

Founding Member
Feb 8, 2001
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First, the graph, mods include LT's & O/R-H with stock mufflers, JLT-II CAI and Bama tune, and CMCV deletes.

dynoql9.th.webp

Power numbers I think are pretty good, but could be a lot better. FYI, torque is roughly 320 and fairly constant, judging by the graph. Mainly, it's that I make peak power at roughly 5K RPM (where torque drops off), and that it's steady until almost 6k where it drops slightly. So something is choking my engine at around 5k and killing it at 6k. It seams like it a lot of people are making good power past 6k, so I would tend to think that it's not the heads/cams. Thing is, that only really leaves the throttle body and axle back, and I have serious doubts that it's the TB. Any thoughts?

As for the install of the LT's, huge pain in the ass. Took about a day and a half, but if I did it again I should be able to cut that down to a day. Main tricks, remove the steering shaft and don't put it back in until your done. Unbolt the motor mounts (I replaced them with prothane, and rather like the feel of them) and jack the engine up about 2-3 inches. Between the two you should be able to move the engine from side to side about 4-6 inches (depending if you've done the LT on the other side yet). Both sides are a huge pain, but I'd say the passenger side was worse. Snaking the LT by the bell housing, even with the starter out, was almost impossible.

The sound, IMHO, of LT's and O/R-H and stock mufflers is bad, fairly raspy and very raunchy and really loud. If you like that, then there's lots of it with basically no drone. But not much low rumble to it, which is what I'm really after. The one nice thing is that it's almost stock-sounding at idle and low cruising RPM. I have heard most of the files in the sound bites thread, but what you guys would suggest? Looking for a low rumbling (muscle car) exhaust with no raspyness to it. I'll take drone so long as it's deep and not raspy. Mostly considering Mac or Flowmaster. Kooldawg, still got your old flows?
Dan
 
Who's LT's do you have. I took about 5.5 hours to get mine on, but have done two sets since and knocked it down to roughly 4 hours start to finish.. All were kooks or ARH's and the steering shaft stayed in. I pulled the motor mounts that's a given and plucked the starter, However I had room to spare on the passenger side with the starter out - which is why I ask what set you have.

I stayed with a catted x and think it sounds perfect as is. So I'm in total agreement with you there..
 
OBX. Fit and finish is very good, but because of that tube that swings out on the passenger side header, getting it up to the engine was a huge pain. My idea of a day is roughly 6 hours, so we're probably about on the same page. It's possible to get the drivers side in with the steering shaft in place, I just like the extra room. And for OBX or JBA headers it helps a lot to have some extra room on the passenger side.

I'm thinking about welding some cats in, frankly it's just a bit louder than I like it and an axle back is only going to make it louder...
Dan
 
That does sound pretty good. Right now I'm deciding between the FRPP stingers, Bassani Race (thanks for the tip) and the Pypes mid-muffler system. All seem to sound really good, and I'm leaning towards the pypes system due to price.
Dan
 
First, the graph, mods include LT's & O/R-H with stock mufflers, JLT-II CAI and Bama tune, and CMCV deletes.

dynoql9.th.webp

Power numbers I think are pretty good, but could be a lot better. FYI, torque is roughly 320 and fairly constant, judging by the graph. Mainly, it's that I make peak power at roughly 5K RPM (where torque drops off), and that it's steady until almost 6k where it drops slightly. So something is choking my engine at around 5k and killing it at 6k. It seams like it a lot of people are making good power past 6k, so I would tend to think that it's not the heads/cams. Thing is, that only really leaves the throttle body and axle back, and I have serious doubts that it's the TB. Any thoughts?

As for the install of the LT's, huge pain in the ass. Took about a day and a half, but if I did it again I should be able to cut that down to a day. Main tricks, remove the steering shaft and don't put it back in until your done. Unbolt the motor mounts (I replaced them with prothane, and rather like the feel of them) and jack the engine up about 2-3 inches. Between the two you should be able to move the engine from side to side about 4-6 inches (depending if you've done the LT on the other side yet). Both sides are a huge pain, but I'd say the passenger side was worse. Snaking the LT by the bell housing, even with the starter out, was almost impossible.

The sound, IMHO, of LT's and O/R-H and stock mufflers is bad, fairly raspy and very raunchy and really loud. If you like that, then there's lots of it with basically no drone. But not much low rumble to it, which is what I'm really after. The one nice thing is that it's almost stock-sounding at idle and low cruising RPM. I have heard most of the files in the sound bites thread, but what you guys would suggest? Looking for a low rumbling (muscle car) exhaust with no raspyness to it. I'll take drone so long as it's deep and not raspy. Mostly considering Mac or Flowmaster. Kooldawg, still got your old flows?
Dan


Your problem is you have an O/R pipe, get a pipe with cats. The cats will smooth out the sound and give you a deeper tone. Go with some magnapacks or FRPP stingers for mufflers.
 
Dan, if you don't like the sound of the stock mufflers then you probably won't like any other chambered mufflers on these cars either.

Nothing beats the sound of chambered/offroad exhaust on the sn95 but I don't care for it on the s197. I've already had MAC plus the prochamber and didn't like the sound at WOT.

Now I have LT's, O/R prochamber, and stingers and love it. No raspiness, no trumpets, just a deep and smooth purr. I'll never change this setup.

It had some trumpets with the stock manifolds but the LT's took care of it.

I recommend just replacing the mufflers with stingers or pypes MM.

Also, that graph looks about par. I don't have mine with me but seems like my HP peeks around 5 grand and flattens out to about 6 grand as well.
 
Just an FYI.. I hear that the mid muffler system is a PITA to get the tips aligned correctly and evenly.

Yeah, I noticed in some of the pictures that the mufflers are not welded in, but clamped in place, meaning four more points of adjustment. But from what I have heard they sound great and are ~$150 cheaper than the other two. I'm good with tools, so I'll take the price cut for a bit of extra work.

Thanks for the advice guys. From what I can tell, the stingers/bassani race/pypes MM have the sounds I want, must be the smaller strait-through mufflers. I also like that the pypes replaces the mid-pip, as from what I have seen of the stock one it's not really that well bent (better than pre 05's, but not as good as aftermarket stuff). I doubt that will really make a difference but it's nice to know.

If I still don't care for the note after the new mufflers, I'll look into getting a set of high-flow cats welded in.
Dan