Loss of torque with duals without a crossover?

[87mefull]

I heard that there is probably a noticeable difference in torque with duals without a crossover, but my car seems much slower off the line than what is was before.

Will I see a difference with mustang headers and an h-pipe if I bolt them up to the current cat-back dual exhaust system? Or will I be alright leaving it the way it is for now.

[89LincolnTWNcar]

what kind of engine you running? the 150hp or the 225hp 5.0? Mustang headers bleh, shell out 40 more bucks and get a used set of Flowtechs or MAC or something like that. Shorties and a mustang H-pipe will up power a good bit. If you have the loPo motor get 2" out the back, HO get 2.25

[gadget73]

Duals do lose you some low end torque, especially without a crossover. The factory duals have a crossover behind the cats. I'd suggest having yours modded to add a crossover first before you go looking to replace the parts up front. Headers will help but they aren't gonna mate perfectly to the stock cats. I hacked mine and got it to work, but its probably not worth the trouble to install headers to those stock pipes. Mustang H or X pipes fit very nicely, but they won't fit to your current mid pipes. Forward of the mufflers will end up being donations to the scrap pile and you'll have to replace those mid pipes with either a 2.25 S10 or 2.5 extended Mustang one.

[87mefull]

I guess I'll eventually have to weld in a crossover because I allready have a custom dual exhaust setup thats not worth hacking up yet. I have custom 2'' inch midpipes to 2.25'' incenerator mufflers connected to 2.25'' tailpipes. It performs nicely once its going after 20-25mph, just hard to get going from a stop.

Would maybe putting on a set of 1990 Lincoln Town Car headers help with the low end torque loss as a cheap fix?

[89LincolnTWNcar]

90 towncar headers would free up airflow (supposedly) which would further decrease torque

[gadget73]

Those 90 manifolds are probably only marginally better than the stock iron. I doubt it would make enough difference to bother with. They do weigh less and aren't nearly as ugly though, which is a plus I suppose.

[Chevyguy]

The factory crossover as far as I can tell is more for noise control and to balance the exhaust flow between banks (for 02 readings?)

With a H pipe there is not much actual FLOW through the H, but an X pipe certianly does mix both sides.

Anyways it's all about Velocity and scavenging.

Running a 4" system will give no back pressure but no torque, wonder why??

Keeping the exhaust gas hot keeps the velocity up, increasing the area cools it off and slows the gas down this then reduces the suction effect in the cylinders.

87 Mefulls car may have too large mufflers/tailpipes but I suspect his problem may be from the removal of the cats if they were in fact removed. If the cats are still there, then the motor or something in the EFI system is not right

[p71towny]

The h pipe is needed, I wish I would have put one on my chevelle, I will on my 70 thats for sure. X pipe is for higher rpms.

[88MercWagon]

Would an aftermarket Mustang X-Pipe fit on a panther?

[Mercracer]

Put your money into the engine first before you worry about having the perfect x/h pipe. I am all in support of aftermarket shorty headers and a basic aftermarket Mustang 2.5" H pipe, but I do not see the sense in spending a pile of money on your exhaust system with a stock motor. It can easily cost you an EXTRA $150 or more for a X pipe over a basic H pipe. $150 is nearly half the cost of a good basic nitrous system.

[grandpaslincoln]

I'm just gonna get one of those balance tube kits from summit, costs $30 bux, welds or clamps on. Same damn thing

[87mefull]

The factory crossover as far as I can tell is more for noise control and to balance the exhaust flow between banks (for 02 readings?)

With a H pipe there is not much actual FLOW through the H, but an X pipe certianly does mix both sides.

Anyways it's all about Velocity and scavenging.

Running a 4" system will give no back pressure but no torque, wonder why??

Keeping the exhaust gas hot keeps the velocity up, increasing the area cools it off and slows the gas down this then reduces the suction effect in the cylinders.

87 Mefulls car may have too large mufflers/tailpipes but I suspect his problem may be from the removal of the cats if they were in fact removed. If the cats are still there, then the motor or something in the EFI system is not right

Still have the original cataytics and headers on my car and your right it might be something else. I have stock size midpipes, just 2.25 inch tails and mufflers. The low end torque loss isn't that much though, my car just seemed a little quicker off the line before I changed the exhaust system.

I took it out the other day for a nice 80 mile cruise and it does have some other problems. The car still doesn't idle right at times and the tranny shifts are kinda sloppy. It also has trouble shifting going up steep hills. The TV pressure probably needs to be adjusted along with maybe fixing some other sensors.

I was probably going to go with the summit h-pipe kit or just weld in a crossover to the existing midpipes.

[Archangel]

I guess you can weld a crossover to the current midpipes, but if they are stock size why not just replace them with a stock H-pipe from a Panther? Don't know how it goes for the CrownVics and MGMs, but the Cartier and some Signature Series TownCars have stock duals with an H-pipe, find yourself one and just swap it in.

[87mefull]

I might consider that, it was just when I was looking around to replace the entire exhaust system, the stock h-pipe from the cataytics to the muffler was about $150. I'll have to find the reciept because I think my mufflers have 2.25 inch inlets/outlets because of the larger tailpipes, but im not sure though.

[gadget73]

Just have a crossover added into your existing pipe. Its nothing that someone with a bit of pipe and welding skills can't handle.


And yes, a Mustang H will fit a panther but it won't fit up to the stock manifolds or mate to the stock H pipe. You'd need Mustang or compatible shorty headers and different mid pipes to make it work.