I'm struggling to hold 19psi of boost which usually tails off around 4500rpm, I can get boost spikes of 24psi.

 

At the moment I have a 2.5inch twin exhaust with crappy gaskets which don't fit properly and probably reduce bore size it has also been somewhat squashed from my low ride height.

I have since raised the ride a touch and before forking out £1000 for a custom fabricated 3inch exhaust (which they can neatly tuck under the car to avoid being squashed) I want to know if it's going to be beneficial or a waste of money, either way it still needs changing.

I want to know if it will effect the way the turbos are losing pressure and if I can squeeZe a few more horses out when it's remapped.

 

Managed a 12.6sec 1/4mile few years back

Currently 470bhp

Gt25r turbos

Godspeed intercoolers

Q45maf

Forged engine rebuild

Shit exhaust

Loads of other stuff I can't remember

 

I'm struggling to hold 19psi of boost which usually tails off around 4500rpm, I can get boost spikes of 24psi.

 

At the moment I have a 2.5inch twin exhaust with crappy gaskets which don't fit properly and probably reduce bore size it has also been somewhat squashed from my low ride height.

I have since raised the ride a touch and before forking out £1000 for a custom fabricated 3inch exhaust (which they can neatly tuck under the car to avoid being squashed) I want to know if it's going to be beneficial or a waste of money, either way it still needs changing.

I want to know if it will effect the way the turbos are losing pressure and if I can squeeZe a few more horses out when it's remapped.

 

Managed a 12.6sec 1/4mile few years back

Currently 470bhp

Gt25r turbos

Godspeed intercoolers

Q45maf

Forged engine rebuild

Shit exhaust

Loads of other stuff I can't remember

 

3" Downpipe, testpipe/decat, catback. That's the order of benefit, with catback only helping a little at very high power.

 

Power and torque should increase, your peak boost will probably reduce

3" Downpipe, testpipe/decat, catback. That's the order of benefit, with catback only helping a little at very high power.

 

Power and torque should increase, your peak boost will probably reduce

So I would have to change downpipes aswell? For it to make a difference? Was thinking 3inch just after downpipes. No? My current downpipes I think are stainless z1 downpipes and they have been fibre glass wrapped same as my AMS manifolds.

So I would have to change downpipes aswell? For it to make a difference? Was thinking 3inch just after downpipes. No? My current downpipes I think are stainless z1 downpipes and they have been fibre glass wrapped same as my AMS manifolds.

When it comes to turbos, the bigger you can fit the better.

Back pressure is the enemy.

When it comes to turbos, the bigger you can fit the better.

Back pressure is the enemy.

That's exactly what I needed to hear....

Screamer pipes and 3inch baby

That's exactly what I needed to hear....

Screamer pipes and 3inch baby

You'll need different manifolds to run external wastegates and screamers, if you was only planning 3in cat back it wouldn't cost £1000 for a custom exhaust, 3in elbows down pipes and back is the best way to go

You'll need different manifolds to run external wastegates and screamers, if you was only planning 3in cat back it wouldn't cost £1000 for a custom exhaust, 3in elbows down pipes and back is the best way to go

You'll need different manifolds to run external wastegates and screamers, if you was only planning 3in cat back it wouldn't cost £1000 for a custom exhaust, 3in elbows down pipes and back is the best way to go

 

Why do screamer pipes need external wastegates? I thought you just let them vent to atmosphere, while the rest goes through to the rear of the car?

You'll need different manifolds to run external wastegates and screamers, if you was only planning 3in cat back it wouldn't cost £1000 for a custom exhaust, 3in elbows down pipes and back is the best way to go

 

Why do screamer pipes need external wastegates? I thought you just let them vent to atmosphere, while the rest goes through to the rear of the car?

Screamer pipes come off the side of external wastegates when the wastegates open they vent via the screamer pipe totally separate from the exhaust system unless you plumb the screamer back into the exhausts further down the system

Screamer pipes come off the side of external wastegates when the wastegates open they vent via the screamer pipe totally separate from the exhaust system unless you plumb the screamer back into the exhausts further down the system

Screamer pipes come off the side of external wastegates when the wastegates open they vent via the screamer pipe totally separate from the exhaust system unless you plumb the screamer back into the exhausts further down the system

 

I'm talking more like this type?

 

Screamer pipes come off the side of external wastegates when the wastegates open they vent via the screamer pipe totally separate from the exhaust system unless you plumb the screamer back into the exhausts further down the system

 

I'm talking more like this type?

 

3" all the way from turbo back if you can. You require the minimum amount of back pressure achievable post turbine housing.

 

On stock turbos, I ran a peak boost pressure of 1.7 bar with standard manifolds and elbows, achieving 482lb·ft at 3900rpm. The way to do it is to concentrate on allowing the VG to breathe. Once that is accomplished, it is about consideration for the rear 2 cylinders. The stock manifolds became a severe restriction when I went to GT2870 turbos, 1.8 bar and 570 bhp.

3" all the way from turbo back if you can. You require the minimum amount of back pressure achievable post turbine housing.

 

On stock turbos, I ran a peak boost pressure of 1.7 bar with standard manifolds and elbows, achieving 482lb·ft at 3900rpm. The way to do it is to concentrate on allowing the VG to breathe. Once that is accomplished, it is about consideration for the rear 2 cylinders. The stock manifolds became a severe restriction when I went to GT2870 turbos, 1.8 bar and 570 bhp.

I'm talking more like this type?

 

 

There not actual screamer pipes just advertised as such there's no benefit from these and just make the exhaust sound like it's blowing

I'm talking more like this type?

 

 

There not actual screamer pipes just advertised as such there's no benefit from these and just make the exhaust sound like it's blowing

3" all the way from turbo back if you can. You require the minimum amount of back pressure achievable post turbine housing.

 

On stock turbos, I ran a peak boost pressure of 1.7 bar with standard manifolds and elbows, achieving 482lb·ft at 3900rpm. The way to do it is to concentrate on allowing the VG to breathe. Once that is accomplished, it is about consideration for the rear 2 cylinders. The stock manifolds became a severe restriction when I went to GT2870 turbos, 1.8 bar and 570 bhp.

 

So, can the average exhaust specialist fabricate an exhaust from turbo back without taking out the engine, I remember how hard it was to replace my downpipes, could just about get to the bolts.

3" all the way from turbo back if you can. You require the minimum amount of back pressure achievable post turbine housing.

 

On stock turbos, I ran a peak boost pressure of 1.7 bar with standard manifolds and elbows, achieving 482lb·ft at 3900rpm. The way to do it is to concentrate on allowing the VG to breathe. Once that is accomplished, it is about consideration for the rear 2 cylinders. The stock manifolds became a severe restriction when I went to GT2870 turbos, 1.8 bar and 570 bhp.

 

So, can the average exhaust specialist fabricate an exhaust from turbo back without taking out the engine, I remember how hard it was to replace my downpipes, could just about get to the bolts.

There not actual screamer pipes just advertised as such there's no benefit from these and just make the exhaust sound like it's blowing

 

Ok bugger that idea then.

There not actual screamer pipes just advertised as such there's no benefit from these and just make the exhaust sound like it's blowing

 

Ok bugger that idea then.