Exhaust options

[1987cp]

You got it,simple as making new mounting plates for them,and welding it up.Probably why I don't have the annoying interior Drone most FM users complain about.

Interesting. 'cause if I could put my Flowmasters back on without a nasty drone....... I've got a set of 2.5" in/out 40 Series Delta Flows laying around. What model do you have?

[torquelover]

A change from a 2:73 to a 3:27 cured mine. You don't remember my car droning, do you Michael? I thought Delta Flows were supposed to drastically cut the drone? I have old school 2-chamber flows.

[1987cp]

A change from a 2:73 to a 3:27 cured mine. You don't remember my car droning, do you Michael? I thought Delta Flows were supposed to drastically cut the drone? I have old school 2-chamber flows.

Good thought. I guess it does tend to be worst between 1500 and 2000 rpm. Last experience with these guys was on the LTD with the 2.26 gears - talk about intolerable!!!

[Archangel]

they even made 2.26 gears? damn, that must take forever to pick up speed

[LTDMan83]

Interesting. 'cause if I could put my Flowmasters back on without a nasty drone....... I've got a set of 2.5" in/out 40 Series Delta Flows laying around. What model do you have?

I have the 40 Series 2-Chamber Flowmasters,which aren't the same as the Delta Flow series.

I love the sound,but I recently got to hear the new 44mag Delta Flow series,long story short,I'm now sold on them.I'm actually planning on swapping some in as soon as $$$ permits.

[Nathan in MI]

they even made 2.26 gears? damn, that must take forever to pick up speed

I've driven Chrysler products with 2.26 gears...quite tame on the highway with no overdrive, but around town,

[1987cp]

I have the 40 Series 2-Chamber Flowmasters,which aren't the same as the Delta Flow series.

Right-O, nominally quite a bit louder. Hard to do really accurate comparisons without installing both models back-to-back on the same vehicle, though.

Hm, weird - appears they're no longer marketing the old 40 Series, the original two-chamber with only one internal deflector. Interesting the new variations they've introduced:

Super 44:


Super 40:


40 Series Delta Flow:

[gadget73]

they even made 2.26 gears? damn, that must take forever to pick up speed

79's with the C4 tranny got them. It was an attempt to make some fuel economy with only 3 gears. They probably did suck, 128 hp, 4,000 lbs, 2.26 rear. Yeah that just screams performance

[1987cp]

79's with the C4 tranny got them. It was an attempt to make some fuel economy with only 3 gears. They probably did suck, 128 hp, 4,000 lbs, 2.26 rear. Yeah that just screams performance

No shit!

Although, it's still somewhat entertaining to be able to go 70mph in First gear at a comparatively low 5,000 RPM. Theoretical top speed in this car given sufficient top-end power and high RPM's is just plain scary. Let's see ....... proportionally speaking, 7,000 rpm in First would be maybe 98 mph ...... First gear being about 2.4:1, direct-drive would give perhaps 235mph at 7,000 rpm in Third.

[Archangel]

79's with the C4 tranny got them. It was an attempt to make some fuel economy with only 3 gears. They probably did suck, 128 hp, 4,000 lbs, 2.26 rear. Yeah that just screams performance

Well, actually that equals like 2200rpm at 75mph assuming 26" rear tires, those engines better had some good low-end torque. Is 2200rpms about when said engine's fuel efficiency is highest?

[Archangel]

No shit!

Although, it's still somewhat entertaining to be able to go 70mph in First gear at a comparatively low 5,000 RPM. Theoretical top speed in this car given sufficient top-end power and high RPM's is just plain scary. Let's see ....... proportionally speaking, 7,000 rpm in First would be maybe 98 mph ...... First gear being about 2.4:1, direct-drive would give perhaps 235mph at 7,000 rpm in Third.

Well since you brought up the 1st gear ratios:

C4: 2.46(1st) x 2.26(rear) x 26"(tires) x 2000rpms = 28mph

TH350: 2.52(1st) x 3.07(rear) x 32"(tires) x 2000rpms = 25mph

The C4 passenger car combo will reach my 25mph at 1800rpm, which is only like 10% difference - not bad, not bad at all. However, as I said low-end torque is needed, lots of it - Mike, what is your 306 supposed to have, according to the desktop dyno?

[torquelover]

When I had 2:73's, I swear the car was still "On the converter" across the intersection. The car would boom like mad from 35-40 MPH all the way up until about 75 MPH. The 2.26 rear must have been rough, but maybe less so because of the C4. When I was at my buddies house last (1987cp was also in attendance) he had my old-school 2-chamber Flows off my Mustang still in his garage. They were offset/offset, 2.5". Anyone want them, PM me and I'll see if they're still on his shelf.

Here's an easy site for what you guys are doing:
http://www.f-body.org/gears/

[1987cp]

Well since you brought up the 1st gear ratios:

C4: 2.46(1st) x 2.26(rear) x 26"(tires) x 2000rpms = 28mph

TH350: 2.52(1st) x 3.07(rear) x 32"(tires) x 2000rpms = 25mph

The C4 passenger car combo will reach my 25mph at 1800rpm, which is only like 10% difference - not bad, not bad at all. However, as I said low-end torque is needed, lots of it - Mike, what is your 306 supposed to have, according to the desktop dyno?

Maybe as high as 280hp with a very flat 380-plus lb-ft, assuming open exhaust. I think that's maybe 30hp/30lb-ft optimistic, but it does pull this thing around pretty well since the spark-advance mods. I like what happens to the curve if I retard the cam, but that's a project for after I get a high-rev governor. Of course, that engine is in the 3.27 geared car - the 2.26 car has my rebuilt lowpo with a carb and HO cam swap, nothing terribly special, probably making about 180hp/290lb-ft last I drove it. Should feel a little stronger once I get my lard backside around to installing the lower-revving intake and those E7's I keep talking about ad nauseum.

[Archangel]

Interesting, wonder how my 350 compares to all that, it pulls real strong even with the 3.07 rear gears and 33" tires.... What data you need to dyno an engine in your program? Alternatively, where did you get the program from?

[1987cp]

Interesting, wonder how my 350 compares to all that, it pulls real strong even with the 3.07 rear gears and 33" tires.... What data you need to dyno an engine in your program? Alternatively, where did you get the program from?

This version of Desktop Dyno doesn't get specific about intake and exhaust characteristics; you just input your head flow data, cam sheet specs, compression, intake and exhaust generalities, and that's about it. It also doesn't output data under 2000rpm, which bugs me a bit since in the real world our motors do operate at 1200-1800 some of the time, but oh well. :p