Exhaust specs/places 2L 8v racecar

[AlexTDi]

Hi guys,

I'm getting close to the point that I need to get a branch and full exhaust on the Polo Racecar, it has a 2L 8v 2E motor and I've been advised to go with a 4-1 branch as it will suit my application.

1. What sizes would you guys recommend for the system? I want it to be loud but not so loud that I can't hear myself, I'd prefer a deeper sound then a screamer.
2. depending on the above 1 or 2 boxes?
3. I'd like some pops and bangs on deceleration but I think that is done more on the fuel and timing side or will exhaust size also determine it?
4. JR Exhausts is really close to where the car is situated, is it simple enough for them to do the job or should I go to TNT or TMS?

[6teen_valve]

speak to sarel for spec's on a zorst systems.

[AlexTDi]

speak to sarel for spec's on a zorst systems.

Yea I did give me a rough idea hence the 4-1, He would be making it but hasn't done one for a 2E in a Polo so would prefer someone else to get it done

Do you have a 57mm system on your mk2?

[panic-mechanic]

How is a 2E in a polo hugely different ? Very similar to a mk3 and that was done plenty.
Any really bad tuner can give you pops and bangs. A good tuner on a proper map should not.
It comes from too much fuel, too slow timing and a big exhaust.

[6teen_valve]

speak to sarel for spec's on a zorst systems.

Yea I did give me a rough idea hence the 4-1, He would be making it but hasn't done one for a 2E in a Polo so would prefer someone else to get it done

Do you have a 57mm system on your mk2?

I run a 4-1 branch,42 or 45mm runners, and run a 63mm from the collector and then it step's down to a 57mm.

although I am led to believe that a 63mm single box system would be better for my setup, now 16v on throttles, cams and hi comp, race fuel etc,etc.

[ICE King]

For a Deep sound - Resonator in the middle and silencer at the back
For Loud - simply remove the resonator and only silencer at the back
For extra loud - No silencers Resonator at the back.

You haven't stated any mods but a 57mm exhaust from front to back is more than enough.

Think about it this way , The advantage of the 8 valve is the torque lower down in the rev range ,By using 4-1 branch and a non progressive system you loose the torque at the bottom but gain at redline . on the track, what would you need more?

If you constantly in the higher of the rev range -I agreed 4-1(this is where the difference is between the 4-2-1 vs 4-1)
Most 16 valve motors run 4-1 even from factory and you having a 8 valve will mean you can get quicker away from the 16 valve but they will fetch you if the straights is long enough but since your power is capped the 16 valve will be choked.

[ICE King]

Just my 2c .....If the track does not have any long straights and you need the power more out of the bends , modify the the 8 valve for early peak power, this is the reason you choose a 8 valve?

For example:
8 Valve - 90kw @4000rpms , 190nm@ 3500rpms
16 Valve will make more power overall but at the same revs as above the 8 valve will make more power meaning you'll be quicker.

[AlexTDi]

How is a 2E in a polo hugely different ? Very similar to a mk3 and that was done plenty.
Any really bad tuner can give you pops and bangs. A good tuner on a proper map should not.
It comes from too much fuel, too slow timing and a big exhaust.

Yea similar up to the point it hits the subframe, It's just not an off the shelf product like it is made for a Citi.

I want the pops and bangs but with a good map

[AlexTDi]

For a Deep sound - Resonator in the middle and silencer at the back
For Loud - simply remove the resonator and only silencer at the back
For extra loud - No silencers Resonator at the back.

You haven't stated any mods but a 57mm exhaust from front to back is more than enough.

Think about it this way , The advantage of the 8 valve is the torque lower down in the rev range ,By using 4-1 branch and a non progressive system you loose the torque at the bottom but gain at redline . on the track, what would you need more?

If you constantly in the higher of the rev range -I agreed 4-1(this is where the difference is between the 4-2-1 vs 4-1)
Most 16 valve motors run 4-1 even from factory and you having a 8 valve will mean you can get quicker away from the 16 valve but they will fetch you if the straights is long enough but since your power is capped the 16 valve will be choked.

Mods are stage 3 head built by Sarel with 298 cam and all supporting goodies, for the track we ideally stay between 4500 rpm and up so no need for low down torque hence the 4-1, the bolded part is exactly why I went 8v, rather a worked 8v then a stock 16v, power delivery will be better where I need it.

Think I'll go with this setup "For a Deep sound - Resonator in the middle and silencer at the back"

one thing I didn't like about the Golf, it was so loud I couldn't hear anything

[ICE King]

For a Deep sound - Resonator in the middle and silencer at the back
For Loud - simply remove the resonator and only silencer at the back
For extra loud - No silencers Resonator at the back.

You haven't stated any mods but a 57mm exhaust from front to back is more than enough.

Think about it this way , The advantage of the 8 valve is the torque lower down in the rev range ,By using 4-1 branch and a non progressive system you loose the torque at the bottom but gain at redline . on the track, what would you need more?

If you constantly in the higher of the rev range -I agreed 4-1(this is where the difference is between the 4-2-1 vs 4-1)
Most 16 valve motors run 4-1 even from factory and you having a 8 valve will mean you can get quicker away from the 16 valve but they will fetch you if the straights is long enough but since your power is capped the 16 valve will be choked.

Mods are stage 3 head built by Sarel with 298 cam and all supporting goodies, for the track we ideally stay between 4500 rpm and up so no need for low down torque hence the 4-1, the bolded part is exactly why I went 8v, rather a worked 8v then a stock 16v, power delivery will be better where I need it.

Think I'll go with this setup "For a Deep sound - Resonator in the middle and silencer at the back"

one thing I didn't like about the Golf, it was so loud I couldn't hear anything

Motor recipe sounds perfect then , suppose once dyno'd you'll get a better indication where peak power is and you can chop and change till you happy.

With the deep sound , you'll hear more throttle/motor noise than exhaust.

What was the exhaust setup in the golf?

[AlexTDi]

4-1 57mm to single box in the rear not sure if it was a silencer or resonator, I'd much rather hear the motor and other people's motors too as that's ultimately what you need in racing so you don't stare at the mirrors all the time, I'm pretty sure If I could have heard my motor pinging 2 years back it would have been a timing change and not a rebuild.

[panic-mechanic]

All racecars run a single silencer in the back. Resonator kills power.

[ICE King]

All racecars run a single silencer in the back. Resonator kills power.

Didn't know that, There you go Alex from the boffin himself.

[AlexTDi]

All racecars run a single silencer in the back. Resonator kills power.

Thanks Panic