CSP python exhaust question

[nicolas]

hey,

like i stated in my other post i have now installed a type3 python exhaust. years ago when they came out i must honestly say i wasn't too taken by them. the tip would/could a lot better if it had a nice flared tip, in resemblance to the old exhausts, but it has a rounded of tip, more like an audi TT (that is what Georg and i thought back then). but there aren't too many options and i know the csp is quality. so i didn't want the magnaflow exhaust hanging under the valance anymore. imust say it looks a lot cleaner and fits perfectly.

now my wife did the testride on thursday and i had a go at it yesterday. this thing is a lot more quiet, but not too quiet and boring. it has a very nice sound.

performance-wise i have a question. it doesn't perform as good as the previous setup (turbo thomas header, magna flow exhaust). it doesn't make the car pull that strong anymore. it isn't only the sound, but actually the power band seems to have shifted upwards the RPM range. since this is a type3 limited to 6500 rpm engine i want to have the best performance in lower rpms. so are the insert cones an option? i think so, but how can you calculate the right size?

[Torben Alstrup]

No. The inserts is a bad solution generally. I cannot vouch for all possible set ups, but generally, adding the inserts results in an engine that runs significantly warmer. Theoreticly it should not be a problem, but IRL something happens.
The reason that your powerband has shifted upwards is mainly due to the colecctor shape and size. The collector volume and also the trap is too large for smaller and lower rpm engines, but fine for engine that has some displacement and pulls some power it is good.

I think the reason for you "thinking" that the TT header sits lower than the Python may be that the Python header is covered by the muffler, so you only see the muffler when looking at the car from behind. I may be wrong though. But the Python muffler is BIG!

Hinsight is always 20/20. Here is what I would have done: Kept the TT header and replaced the Magnaflow muffler with 2 16" oval Simons or Apple oval mufflers in line, one on each side of the engine, then letting the it exit in the normal position. On a type 3 I will admit that it is a bit of a hazzle to get everything positioned right, but the end justifies the problems  Then you can also deside for yourself which type of end pipe you want.

T

[nicolas]

No. The inserts is a bad solution generally. I cannot vouch for all possible set ups, but generally, adding the inserts results in an engine that runs significantly warmer. Theoreticly it should not be a problem, but IRL something happens.
The reason that your powerband has shifted upwards is mainly due to the colecctor shape and size. The collector volume and also the trap is too large for smaller and lower rpm engines, but fine for engine that has some displacement and pulls some power it is good.

I think the reason for you "thinking" that the TT header sits lower than the Python may be that the Python header is covered by the muffler, so you only see the muffler when looking at the car from behind. I may be wrong though. But the Python muffler is BIG!

Hinsight is always 20/20. Here is what I would have done: Kept the TT header and replaced the Magnaflow muffler with 2 16" oval Simons or Apple oval mufflers in line, one on each side of the engine, then letting the it exit in the normal position. On a type 3 I will admit that it is a bit of a hazzle to get everything positioned right, but the end justifies the problems  Then you can also deside for yourself which type of end pipe you want.

T

thanks, i am not entirely sure what the inserts do, but what you are suggesting did indeed cross my mind. hence the question.
another route in my thinking is that you need back pressure, so by the use of an insert it could be achieved…

as for the 'bigness' of the muffler, this is huge. i did lose soem weight with the removal of the backup light, but i have gained a little with this muffler (sarcasm intended).

the TT setup performed flawless, but the muffler hangs under and behind the apron of the car, that is worse then a beetle, the CSP one keeps it inside the bodywork so i have gained that space, but lost all the space behind the engine and apron because of this setup. i agree.

as for the other options (apple and simons) i must admit i haven't come across them in my search (but i do think Steve's 68 has had a apple muffler on his anglefow engine that Richie was selling). again, this would not work out entirely the way i want it as the header still exits behind the valance and needs to be routed back underneath again. i once had a SS header with a hideaway muffler (very good setup for a very affordable price), and that worked well and got the muffler away from the apron. i have small children and the collector and U-bent from underneath the bumper is dangerous when hot, so i wanted to find a different setup. and the MOT may be passing this setup also easier.

thanks for helping out so fast and i am sure that i will find the lost power again and if all else fails it looks like i need to build a bigger engine to suit the exhaust 

[Torben Alstrup]

Hehe! i guess the back up light was kinda heavy

Let me get this straight. - The TT header was a sidefacing version ?

T

[nicolas]

Hehe! i guess the back up light was kinda heavy

Let me get this straight. - The TT header was a sidefacing version ?

T

no a 'conventional' 4 into 1 straight out middle of the valance type3 version. if it was a sidewinder i would have found a suitable muffler more easily.

[Torben Alstrup]

Ahh, OK. Then it will most likely be difficult to impossible to get the turn to the first muffler inside the rear valance. Your f*cked, pardon my french, or you need to get on the swapmeet and sell your two systems in order to get the one you really want. 
T

[nicolas]

Ahh, OK. Then it will most likely be difficult to impossible to get the turn to the first muffler inside the rear valance. Your f*cked, pardon my french, or you need to get on the swapmeet and sell your two systems in order to get the one you really want. 
T

 

thanks again,

for now this will work, or i will make it work.

[Torben Alstrup]

Something just crossed my mind.
- What is your engine combo ? Heads, CR, cam, rockers ?

[nicolas]

type3 engine

2007cc 78X90.5
10.3 CR
Los banditos heads (reworked, massaged by Stevesvwshop) with 40x35 valves, type3 manifolds with 42 DCNF carbs (i think but am not 100% sure 34 vents)
cam is engle FK44 with 1.25 rockers
stage1 clutch, very light flywheel
009 distributor with electric module.

[Zach Gomulka]

34 vents is correct.

[Georg/DFL]

Nicolas, what header diameter are you running now?

[nicolas]

42mm. the same size the TT was/is. but it seems to be on the big side.
so far i managed to get a cone at work with a 50mm end diameter. i will make something up to fit it and do some tests.

[nicolas]

voila, i fitted a cone (home made one) with a reduction to 50mm from a scrap reduction piece where i fitted a radiused end on and flange. it does look a bit like the one of CSP, so i did a quick test and it isn't noisier and it may work. the bottom end does have a bit more stomp to it. i will see how it drives this weekend.

[nicolas]

i did manage to do some testdriving this week and i can say that i picked up some bottom end power. the car picks up better when i accelerate and it has it's low torque curve again. this is all without 'real' test divices, but the ride is quiter, but not as quite as without the cone. it has a bit more of a grunt on initial take off 

[Jim Ratto]

i did manage to do some testdriving this week and i can say that i picked up some bottom end power. the car picks up better when i accelerate and it has it's low torque curve again. this is all without 'real' test divices, but the ride is quiter, but not as quite as without the cone. it has a bit more of a grunt on initial take off 

Any change to your carburetor settings? And did you measure any difference in engine temperature before/after your cone?

Thank you,

Jim

[nicolas]

i did manage to do some testdriving this week and i can say that i picked up some bottom end power. the car picks up better when i accelerate and it has it's low torque curve again. this is all without 'real' test divices, but the ride is quiter, but not as quite as without the cone. it has a bit more of a grunt on initial take off 

Any change to your carburetor settings? And did you measure any difference in engine temperature before/after your cone?

Thank you,

Jim

i only have oil temps and they are the same (no highway cruising with or without). it could be hotter though. i should have measured it with a heat gun, but i didn't. so in theory it should/could be hotter, but my engine wasn't performing well. before with the other exhaust i experienced no heat problems, in fact it is the engine with the most CR i have build (10.3) and a relatively short duration cam (FK44) and this engine has an oilcooler with a fan, but it doesn't really need the fan. all engines needed the cooler with fan after 10 - 15 minutes of spiritius driving or highway driving.
so i have been made the same remark in a mail, but so far i haven't found a negative result and i find it very difficult to make conclusive findings without actual test data… it's just taken from what i know and experience.
as for the jetting, i haven't changed it yet, but it may need some work to get it better. the idling is constant and pretty much the same, but the (initial) acceleration has a small bog. i am not entirely sure what top end needs for now.

[Jim Ratto]

Thanks Nicolas. I noticed changing from my unknown brand conventional 1-3/4 merged with 2-1/2" Magnaflow, my engine temperature dropped once I installed 42mm Python. I don't have a cone, and like you, I noticed the engine has become cammier now (in spite of smaller primary ID), so something tells me the primary lengths are better tuned to my engine, or the Python style collector/exit is better. Something else weird too, I was able to go down main jet and pick up throttle response, after going to Python. It just keeps getting better.....

[mg]

lots of good butt dyno info on here.
these guys had some interesting results too. 
https://youtu.be/azPKIjxmmdU