or Login >>         
C4 - DS4 Owners :: Forums :: Coupe and Hatch Pre 2011 cars :: C4 Loeb Register

C4 owner By Loeb Registration

Home   Forum Rules    Forum Help  Conversion Tools
Please Register to enjoy additional Member Benefits
Top Thanked Forum Posts: Today | Week | Month | Year | All time | Most Thanks Given: To member | By user
Author Post
Phil V   
Wed Jun 03 2009, 12:15pm
Member No: #1388
Joined: Oct 21 2007
Location: Doncaster
Georgeous Car and Gorgeous photo's - almost tempted to go out and photogrpah mine now.
Wed Jun 03 2009, 07:10pm
Member No: #9650
Joined: May 27 2009
Location: Bucharest
Thu Jun 25 2009, 06:27pm
Member No: #9650
Joined: May 27 2009
Location: Bucharest
Some pictures taken at an EMMA Bulgaria event.
I had a little fun on a circuit where the event took place after everybody packed up

Fri Jun 26 2009, 02:00am

Member No: #1
Joined: Aug 07 2006
Location: Northumberland
One nice shiny red Loeb, I quite like the white Citroen graphic on the bonnet

Not sure if it would look OK on any other colour than Sport Red though.
Fri Jun 26 2009, 02:48am
Member No: #7889
Joined: Feb 21 2009
Location: Manchester
nice i like, spot on pics
Wed Feb 19 2014, 12:11pm
Member No: #9650
Joined: May 27 2009
Location: Bucharest
Ok, so i haven't written here in like forever but let's wipe the dust a bit on this thread.

Since most of the first modifications done to my car were about my sound system i am going to update it first and then continue with the performance ones.

The new setup is like this: Alpine 9855r head unit tied to a KCA-420i ipod adapter which i enjoy daily, very comfortable to use and provides very good audio quality when using transformed FLAC songs to ALAC which the ipod can read and send to my HU.

I now have 3 amplifiers, all genesis.

I kept the first one, the ultra 4 profile which i am now using for my midbass speakers (in bridge 300w/speaker ), i bought an ultra 2 profile which i am using with my subwoofer also bridged and i bought a 3 series stereo 60 for my tweeters which are now connected directly to the amplifier. The midbass speaker still goes through the original filter because it makes some adjustments to the frequencies and it sounds much better like this.

And finally i changed the subwoofer, just the speaker, i kept the old box and put the new ground zero hydrogen 10" subwoofer in it because it fitted perfectly in the trunk and i can also take it out pretty easily.

The sound right now is great for what can be expected from this budged and without making too many modifications to the rest of the car, because it's a daily driver and i also like to keep it as light as possible for racing events.

The next modifications were performance orientated.

First i went along and bought a Pipercross Viper intake which i am still using but slightly modifying each year when i put back in the "summer intake". I am using only the stock box (without the rest of the piping) for winter because the air is much cooler so it doesn't make much of a difference between the intakes and it also gives me a chance to thoroughly clean the pipercross filter.

With this modification the torque and power increased in the lower part of the rev range and maybe slightly in the middle.

After that i ported and polished the intake manifold and got a bit of grunt gain down low. It is not complete though, i need to polish it some more to make it perfectly shiny on the inside, right now only the big rough bits are polished away.

The next step was a remap, i had it done at a tuner in germany and i am pretty satisfied with the results. Again i gained much more power and torque down low and a bit through the middle and high range but i also gained 400 rpm above the standard limiter and now it revs up to 7800 rpm.

Then i bought a set of 17" lightweight Team Dynamics Pro Race 1.2 WHITE wheels which you will see in the pictures i will be uploading. The weight difference is huge compared to the standard wheels (4kgs/wheel) and of course that can be felt in the way the car handles and accelerates.

At the time i got the wheels i also bought the sport kit from citroen which makes changes to the front and rear bumper as you will see from the pictures

Last thing to get done was the exhaust, mainly because the standard one was getting rusty and i didn't want it falling off on me.

The exhaust was very problematic because no one makes exhausts for this car/engine and i had to get it done custom. I did that actually at local franchise of the TopGear.co.uk that you guys have here in the uk.

Because no one had done this engine they didn't know how to do build it silent and to gain some power. So a trial and error process started in which i have changed 2 intermediary exhausts and 3 backboxes. The main problem was the noise it made after the exhaust got hot. When it was cold it was and still is very quiet, but after a few hard accelerations it gets hot and much much louder.

I am still not completely satisfied with the sound and probably in the future will try and use a valve system that will change from freeflow to a more restrictive route so i can use it quietly. I decided to keep the standard exhaust manifold and cat because they are in good condition and also good for performance. I also kept the stock exhaust tip because it looks great, what you will see in the pictures will be just one from the testing period.

Just so that you can get an idea of what's installed right now on the car, i have a huge intermediary exhaust that was designed much like the standard one. It is 63cm long, about 20cm in diameter and has somewhat of a chamber in the middle of it, it is just an open air one, the inner piping is facing each other directly but they are 15cm appart where the small chamber is.

The inner piping is a perforated 54mm in diameter for this exhaust. The backbox is a another little monster, it is about 40cm long and i believe 25 cm in diameter (bigger than the mid section anyway) and has a straight through free flow perforated pipe of 44mm.

What has really helped to silent the exhaust was increasing the volume of the two, but unfortunately i do not have much more space to use under the car to silent it down even more, without loosing performance by reducing inner piping diameter or by placing chambers.

At this point i think it is a bit restricted due to the 44mm backbox inner piping, but only just a little when going over 6000rpm, much like the standard one actually when over 6000 rpm you could feel the car not really wanting to accelerate as much as it did up to that point. With this one there is still a bit of a restriction but it's a compromise that i have to deal with for now (i am comparing to when i had small volume exhausts and big inner 54mm perforated piping, basically fast free flow all the way)

I hope this will someday maybe help someone, because it was hell for me trying to figure out a good setup for the exhaust.

And if you have any ideas why the exhaust is so loud only when it gets hot please do tell me because it is really annoying.

Related to the performance gain i think you can see a pattern here, almost every modification done got me power and torque down low on the rev range except for the exhaust, i now have about 155NM OR 175NM at the wheels (170NM OR 192NM engine estimated) starting from 2000 RPM depending on which dyno you would like to believe. We have two very different dyno's here, one is very pessimistic and one very optimistic).

I only dynoed on the pessimistic one, but from what other cars got on both dynos in the same conditions and only a day apart there is a difference of about 13% between them so i just did the math because there was no point in wasting my money on both dynos. Taking this into consideration the max figures are 151WBHP/184NM and 168HP/197NM estimated at the engine and adding 13% for the other dyno they should be 175WBHP/207NM and 190HP/220NM estimated at the engine.

On the street i can tell you there is a huge improvement, the 0-62 time is around 7 sec, the test was done before getting the exhaust done so now it's most probably less also because i have fixed a problem i had when changing fast from 1st to 2nd (will talk about this later).

All in all i think the performance is good for a car that is comfortable, has a great sound system and that weighs 1400kgs with me inside and a quarter of the tank filled when in "racing" mode and 1440kgs on a daily basis in the same conditions.

Having these said i will make another post later about some other less significant changes and maintenances.

And some pics, with more to come later on.

Wed Feb 19 2014, 02:58pm
Member No: #27235
Joined: Aug 29 2012
Location: Lancashire
love that front bumper! looks really smart. Cars looking lovely
Wed Feb 19 2014, 03:07pm

Member No: #2
Joined: Aug 12 2006
Location: Manchester
Way you have the system setup with audio. Would put the 9855R into 3 way mode (no rear speakers) that way you should be able to time align each front speaker individually and then adjust the crossover on it from the head unit and get rid of the original crossover that came with the speakers.

So 6 channels, 4 to the front speakers and 2 to the sub. What you usually do when you run different amps up front. Should be able to make it sound really nice if you dig into the proper setup menu in the 9855 the one that is hidden.

If I remember correctly it's a long press of the menu button to get to it. Been a long time since I had my 9855R. Also worth disabling the onboard amp and few other things.
Wed Feb 19 2014, 03:14pm
Member No: #24127
Joined: Feb 05 2012
Location: Bexhill on Sea
Looks great!
Wed Feb 19 2014, 05:00pm
Member No: #27235
Joined: Aug 29 2012
Location: Lancashire
How much was the sport kit for the bumpers pal? Did you just buy them from a dealer?
Thu Feb 20 2014, 01:35am
Member No: #9650
Joined: May 27 2009
Location: Bucharest
@wozza i do have the system in 3 way mode and both the crossover and time alignment are configured, so the frequency cut off is done through the HU, but i still use the original filters on the midbass speakers because it somehow changes the phase and makes it sound warmer and better, it is most probably a design made to improve the speakers by the manufacturers.

I have seen other systems that use manually created filters to improve the sound and not for frequency cutting. The original filter has a pretty big tolerance for both high and lowpass which i never reach because they would go into the frequency territory of the subwoofer or of the tweeters, so it's still the HU that chooses where to cut off. And i do have different setups for listening daily or at car audio competitions. My car was actually champion in it's class in EMMA 2009.

Also i did disable the internal amplification and another thing which i cannot remember right now.

And you were correct, to get into the advanced menu, you have to press the menu button for 3 seconds.
But i do thank you for your thoughts and hope maybe i could get an opinion on the exhaust issue.

@hill_bill10 the sport kit was bought from a citroen dealer and it costed me in 2011 around 350 pounds but right now it is around 250 but the prices may vary in different countries and also dealers (maybe you can get a discount).

You just have to have in mind that you need the pre-facelift bumper to install that sport kit and long with that the hood, so it might not be worth it, because i think (i'm not 100% sure) you also have to change the headlights and wings to make everything fit.
Thu Feb 20 2014, 03:16am

Member No: #1
Joined: Aug 07 2006
Location: Northumberland
The kit is still available from Citroen Part Number 9400A4 @ £571.31 UK retail inc Vat but has gone up considerably since you got yours.
Thu Feb 20 2014, 03:44am
Member No: #9650
Joined: May 27 2009
Location: Bucharest
Well in Romania right now you can buy that kit from a Citroen dealer for 1335.08 RON including VAT which is around 250 pounds.
Thu Feb 20 2014, 08:32am
Member No: #27235
Joined: Aug 29 2012
Location: Lancashire
jeez thats a lot dave! would be cheaper to get it abroad and get it posted then haha.
Thu Feb 20 2014, 04:07pm
Member No: #24121
Joined: Feb 04 2012
Location: Cambridgeshire
Looking very nice indeed...! VTS Loeb too, excellent...!
Go to page   <<        >>   

Jump:     Back to top

User Colour Key:
Head Administrator, Administrator, Forum Moderator, Forum Moderator, Premier Member, Technical Expert, New C4 and DS4 Forum Moderators, Member