The Triumph Dolomite Club - Discussion Forum

Could you fit a sprint exhaust from the manifold back and get a manifold to fit it up? Would be a cheaper option to get a big bore exhaust system

Mnaifold is on teh other side of the engine. I have an 1850(TR7) engine going to a sprint sports exhaust. May be a tad tricky to get across under the car in the required distance as the gearbox is in the way.
However, no reason you couldn't use a single box on a 1500, and just use a straight pipe connected to the 1500 downpip. Well, may need a couple of bends....

You could possibly use a Sprint twin tailpipe section mounted (a la Sprint) on the nearside.


For a silencer, a decent single box will be okay (decent is going to cost around £100). An oval box about 35cm will work.
This could be joined by straight pipe to the exhaust front pipe.



Getting from the silencer to the tail section could be tricky because you need to clear the propshaft and back anti roll bar
whilst keeping the exhaust positioned to give ground clearance. You may be able to use flexible exhaust pipe.....?




Ian.

sprint95m wrote:You could possibly use a Sprint twin tailpipe section mounted (a la Sprint) on the nearside.


For a silencer, a decent single box will be okay (decent is going to cost around £100). An oval box about 35cm will work.
This could be joined by straight pipe to the exhaust front pipe.



Getting from the silencer to the tail section could be tricky because you need to clear the propshaft and back anti roll bar
whilst keeping the exhaust positioned to give ground clearance. You may be able to use flexible exhaust pipe.....?




Ian.

plan is to use a spitfire 4-2-1 big bore exhaust manifold to fet flow, run a big straight pipe rearwards over the roll bar, then up to go over the axle, dowh and out the centre with a back box to keep it quiet

Dream on dude....
The spitfire 4-2-1's I know of dont work with the dolly subframe. If they did everyone would be doing it and loosing
the stupid flange gasket.

Jonners

Jon Tilson wrote:Dream on dude....
The spitfire 4-2-1's I know of dont work with the dolly subframe. If they did everyone would be doing it and loosing
the stupid flange gasket.

Jonners

That flange gasket is the worst part of the 1500TC design, even worse than the rust issues. Have to get a custom manifold then

Jon Tilson wrote:Dream on dude....
The spitfire 4-2-1's I know of dont work with the dolly subframe. If they did everyone would be doing it and loosing
the stupid flange gasket.

Jonners

After looking at where it doesn't fit, it looks like if there was I cross between the spit 4-2-1 and the 1500 downpipe, that would be great. If I get my hands on a 4-2-1 manifold and get it "massaged" into shape, I'll see if it's possible to make up a few more and sell them to club members and dolomite fanatics alike

A custom manifold will be costly although the cost can be offset by making several of them. The problems with the twin downpipe and the manifold is that the mating surfaces don't seal properly if they're not perfectly flat (you can get round this with some exhaust paste) and if there's no gearbox bracket then the manifold/downpipe joint will eventually leak due to movement of the downpipe. The bracket keeps the downpipe in place preventing any leaks. It will also prevent the exhaust from knocking on the chassis rail. I had this problem with the 1850 so I reinstated the missing transmission bracket which has done the trick.

Would a midget 1500 one fit?



They drop straight down then across to the centre, you could then attach a bend to run it along the centre of the car.

James467 wrote:Would a midget 1500 one fit?



They drop straight down then across to the centre, you could then attach a bend to run it along the centre of the car.

It doesn't look like there would be enough ground clearance. The reason the spitfire one wouldn't fit is the crossmember being right where the exhaust turns. I was going to modify a TriumphTune spitfire manifold, lop the lower part of (right below the two collectors) and get a piece of pipe bent into a spiral shape to bring it out over the crossmember. The TriumphTune manifold ends in a twin pipe and the second collector is in there so might get that and try to use that.

As a bloke who has made several specials and kit cars there is no reason why not, but I have had 2 Lotus seven type cars and I hate side exhausts so I have made two systems that have rear exhaust for this type of car.
Give yourself at least a day and be handy with a MIG welder!

trackerjack wrote:As a bloke who has made several specials and kit cars there is no reason why not, but I have had 2 Lotus seven type cars and I hate side exhausts so I have made two systems that have rear exhaust for this type of car.
Give yourself at least a day and be handy with a MIG welder!

I was thinking something similar to this, if you can understand my line drawing. Taking the tubular manifold and removing any piping after the collectors and then attempt to bend the pipes out to create more space between the block and the collectors. After the manifold, bending a spiral pipe with the start being mounted onto the manifold. The last collector being parallel to the cross member so a s shaped pipe can be attached to bring it under the car, then straight pipe back with a bent section over the axle

If you can get the primaries to end in the correct spot and at more or less the correct angle, you could use the factory dual downpipe as the secondaries (with the flange cut off of course) then you wouldn't have to fabricate the horribly complicated curves the original makes to get past the subframe nor worry about keeping equal lengths on the secondaries cos it will have been done for you.
Nor will it pay you to make a 4 into 1 collector and a single down pipe, the long secondaries help with torque which is why they are there!

Steve

Carledo wrote:If you can get the primaries to end in the correct spot and at more or less the correct angle, you could use the factory dual downpipe as the secondaries (with the flange cut off of course) then you wouldn't have to fabricate the horribly complicated curves the original makes to get past the subframe nor worry about keeping equal lengths on the secondaries cos it will have been done for you.

Steve

It's something to consider, I'd be using a cropped down 4-2-1 manifold from triumph tune so the primary's are the correct length and all is have to worry about is the secondary length being equal.

Carledo wrote:Nor will it pay you to make a 4 into 1 collector and a single down pipe, the long secondaries help with torque which is why they are there!

From my understanding, 4-1 creates better high end torque, where as a 4-2-1 has better low down torque

Well yes, that is technically correct, but since a 1500 doesn't really have a useable high end, having torque there is a bit pointless. bottom end grunt is far more useful!

Steve