Megane Coach F7R Turbo conversion

[ruzki]

Hi!
my Name is Georg, I'm from Germany and new in this forum.
I would like to introduce myself by showing you my last Megane F7R T turbo conversion project.
I have sold this car 3 years ago but since this forum is named "turborenault.co.uk" I thought this car will fit good in here.

Since it is quite difficult to get a turbo conversion legal here in Germany, I've tried to achieve a OEM´ish look as possible.

I drove this car for approx 20k km with this Turbo and had no problems what so ever.
Technical Data:
- Engine F7R 710 stock
- ECU custom to fit in the original Siemens housing
- Turbo Garrett TB2804 because big turbine housing ar 0.86 good with stock compression ratio basically this is the largest T28 Turbo
- Clutch Helix 8 or 6 pad sinter .. not sure anymore
- Boost 0.9 bar
- hp don't know .. I think around 275hp
- exhaust manifold custom made out of stainless steel .. designed with CAD
- Downpipe 63,5mm stainless steel
- Catalytic converter (very important for me .. i don't like exhaust smell) 200 psi metal oval shaped for maximum possible size
- Exhaust Bastuck 63,5mm all the way with oval end tip .. oval look best on Megane I .. fact!
- 280mm brakes .. stock 262mm in Europe
- stock spring and dampers
- Megane DTI Intercooler
- some intercooler pipe from Megane DTI and DTI air filter housing



Engine bay


ECU.. one of the first versions


Turbo manifold

 

[andybond]

Whoah! Thats pretty cool!

Who did the map ? Looks like a fastchips?

 

[Phase II]

Nice job, F7R turbo conversions are rare these days, they still make very good power when turbo charged.
Got a turbo charged F7R myself (F7R megane bottom end+F7P head) in my 19 16v

 

[Adey]

Nice job, F7R turbo conversions are rare these days, they still make very good power when turbo charged.
Got a turbo charged F7R myself (F7R megane bottom end+F7P head) in my 19 16v

have you got a thread up for it?

 

[Adey]

good work, keep the pictures and vids coming

 

[Big Steve - Raider]

He's sold it Mr @Adey

I have sold this car 3 years ago but since this forum is named "turborenault.co.uk" I thought this car will fit good in here.

Great work @ruzki and welcome to TurboRenault!! It's funny how that MK1 Megane seems to have very much disappeared into obscurity very quickly and there aren't really any left in the UK now.

What have you replaced it with? I'm sure going to the effort you did, there is still some Renault Love in your life...? Or have you replaced it with something reliable and German!

 

[DaveL485]

Unusual, and very cool. I think this shape of Megane just got passed by in the UK, they never really took on.

 

[Adey]

@Big Steve - Raider indeed I saw that, but he must have some more pics and stuff?

 

[Big Steve - Raider]

Unusual, and very cool. I think this shape of Megane just got passed by in the UK, they never really took on.

I remember there being a Blue 16v Coupe in my local dealer that I hankered after for some time...

 

[Adey]

the yellow ones look cool these days, coupe and cab. would be nice with an f4r swap...

 

[ruzki]

Whoah! Thats pretty cool!

Who did the map ? Looks like a fastchips?

I did all by my self, it took me some years to got the engine running comparable to the stock ECU.
Breakthrough in ECU tuning came when i reverse engineered the stock ECU. For example: the Fenix5 ECU has a Dwell time when cranking at round about 29ms.
This dwell time is gigantic..
Also I have to admit that tuning this engine in terms of ECU tuning is very difficult. 6 months ago i made a ECU for an Alpine V6 Turbo and tuned this car afterwards.
Tuning took at most maybe one day, the F7R however took me years.
And since the engine was stock in terms of internal components, I could use the NA maps and only had to add fueling and timing for the boosted areas.

The ECU was completely designed and build by myself.

Test configuration for stock Fenix5 Ecu. Logic analyser ist attached to main Outputs. Trigger signal is generated through an arduino.
Clip is connected to view the ECU values.


PCB Layout was made in KiCAD. This is the schematic for the auxiliary drivers such as EGR or Idle Valve.


This is the layout .. don't know what to tell about it..

 

[ruzki]

Nice job, F7R turbo conversions are rare these days, they still make very good power when turbo charged.
Got a turbo charged F7R myself (F7R megane bottom end+F7P head) in my 19 16v

I like this combo! Big ports, slightly smaller combustion chamber (good with forged pistons). My mate has got a r19 Chamade with F7R 714 Turbo.. i made the ECU and tuning for it.
Would love to see some pictures of your car

good work, keep the pictures and vids coming

Will do sir! If there is an interest in specific things, let me know and i will try to find some old pics.

He's sold it Mr @Adey


Great work @ruzki and welcome to TurboRenault!! It's funny how that MK1 Megane seems to have very much disappeared into obscurity very quickly and there aren't really any left in the UK now.

What have you replaced it with? I'm sure going to the effort you did, there is still some Renault Love in your life...? Or have you replaced it with something reliable and German!

Thank you very much! yes, in germany there are only round about 120 registered f7r Coaches left.. will have a look on the numbers again after the winter
I have replaced it with a Skoda Octavia RS, which is a very very good car. But there are no better cars in the world than Renaults!!
Also i got an Clio 4 RS and one Megane F7R Cab as well as an 20.000km fresh Megane Coach F7R.
I thought about building an 3rd Turbo Megane but the Cab is (in my opinion) not good for such conversion due to the very flexible chassis.
And I don't want to ruin the 20.000 with such conversions.

 

[DaveL485]

The ECU was completely designed and build by myself.

Blimey. I'm impressed!

 

[ruzki]

Thank you!

 

[ruzki]

Before building a exhaust manifold I needed to know what type of manifold I would build.
I had to choose between log and tubular manifold.
A tubular manifold would produce more top end power but would be much more difficult to build.
Also it would be harder to fit since this type is larger.
An log manifold is easier and is smaller but will produce less power.

First step was to draw both manifolds in CAD

log manifold as posted above..
tubular manifold:


Then I made a simplified model of both manifolds for 1D simulation.
I won't go into detail about this 1D simulation.. but the results for the manifolds are:

A tubular manifold would only add 10kW so i decided to go with the log manifold.
The plan was not to go over 220kW so there was no need for an tubular manifold.

 

[ruzki]

The design of the turbo manifold is mostly dictated by the spatial conditions in the engine bay, especially curvature of the firewall (for Megane I.. also Megane II).
I made the mistake to cut and weld the firewall with my first turbo build .. but not this time.
The goal this time was, to design a manifold which fits into the engine bay, does not interfere with the starter motor and provides enough room for the downpipe.
I decide to design a tubular manifold first. If a tubular manifold would fit, the log manifold will fit anyway.
And I would have all the plans needed if I decide to build a tubular manifold in the future.

I started of with a "classic" ram horn design but realised very quick that the turbo needed to be moved more to the left side to provide enough room for the downpipe.


Since I was using the largest T28 turbo housings there was a space problem between fire wall and turbo.
I didn't want to remove the fire wall heat shield since from the beginning of the F7x engine there was always a problem with the heat in this area.
After paint melting under the bonnet Renault decided to put an scoop on the bonnets of r19..
So I evaluated different turbo manifolds regarding their Engine-to-Turbo distance.

The reference was the ELIA turbo manifold which was copied by the chinese.
In terms of space this was the best manifold with approx 178,5mm


In my opinion this turbo manifold places the turbo to far down... so i checked how much space it would "cost" to place the turbo further up.
Approx 185,5mm was the result.. 7mm more.


Then I compared the tubular manifold.
191,3mm was the result .. the worst.
There was still some place between head and Turbo but i could not move the turbo more to the head because i would hit the tubes of cylinder 1 and 2.


Then i had the idea to turn the turbo a bit which resulted in 185,5mm! Yeah!!
So this was the final position for both manifold, tubular and log.



Now I had to make sure that the manifold would not hit the heat shield of the starter motor.. mistake made in my first build.
Although I could have solved this issue with an small aftermarket heat shield, why should I stop here when I could do it properly.
And indeed! The first designs came to far down!



After a lot of time i ended here:

 

[THEOLDBOY]

I admire people like Ruzki. with these sort of skills, way beyond my ability.

 

[DaveL485]

Superb design and planning skills! What software do you use?

 

[ruzki]

To build the Turbo manifold I had to build myself an tool to mark up the tube bends.
I sliced the tube bends in the CAD program and transferred the intersections to the tube bends.


It took me a full day to mark them all up..


I made a fixture with in- and output holes for the purging during welding.
The silencer is for a more even distribution of argon gas.
By this time, the fixture was only spot welded to be able to adjust it a bit if needed.


This method ended in a perfect result, the fitment was perfect!



Manifold ready for welding.


I´m not an professional welder.. but its gas-tight.. my welding will improve later I promise


Manifold fits as intended.
Note the exhaust side is moved away from the head. This way there is enough space for the wastegate rod assembly and the hot turbine housing has a gap to the head.
I made a small wire around the turbo to copy the shape of the full assembly.

 

[DaveL485]

Superb, loving this thread