5 Mk I incl Gordini Twin carbs on a R5 Atmo?

[Mark]

When I lasted visited a rolling road with my R5 Gordini Atmo, the performance was improved, but the fuelling is still not quite right, the engine has had some head work and running a different cam, has anyone experienced fitting twin carbs, such as those in the link below?????????

Renault 5 Alpine Inlet Manifold Long Version
WEBER GENUINE 45 DCOE 152 PAIR CARBS/CARBURETTORS FREE T FUEL UNION

My last power run
5 Mk I incl Gordini - Rolling road nr Derby/Leek way?

Thanks

 

[mick]

i fitted a single 40 dcoe and twin IDF's to a 12 and a 5gts many moons ago......if your racing it or like the track days then they're not too bad but as a daily....they're too sensitive......and you'll have cold running issues.....when u get into them there's a whole lot of emulsion tubes ect.....plus if you decide to buy second hand ones make sure they are not from a a car that has them as original equipment as they will probably not be tunable as they are modified for emissions!!

 

[mick]

with fitting a hot cam its really your idle jet and air corrector thats going to be out a tad,you'd also want to check your second stage butterfly it could be well worn!

 

[Mark]

Thanks for the guidance, the car is fitted with a new Weber 32/36 and an MSD digital ignition system with electronic points. The day I took it for the rolling road sessions I lost count the number of times Peter Burgess tried different jet combinations, I just feel the car has more to offer

 

[mick]

i would expect a cam plus exhaust plus DCOE's to give you an extra 20-25% tops....with n/a......what bhp and torque did it make?

 

[Mark]

Here was the last run, factory output 93bhp, now show 120bhp at the engine, but as you can see from the curve, needs some more work...

Photo by MARK POWLING

 

[slgreavett]

Here was the last run, factory output 93bhp, now show 120bhp at the engine, but as you can see from the curve, needs some more work...

Photo by MARK POWLING

Mark I too am interested in the twin carb set up, from what I can tell there are two types of intake manifold for this engine. They both look similar but you will find that one is perpendicular to the head and one is slightly twisted so that the carb clear the bulkhead. I have been told they don't fit easily easily on a right hand drive, but I'm convinced that they only made one body design for left and right hand drives. Could have been the reason for the remote brake reservoir on the model.
Having said that, I have the group 2 information and there were two builds, one I think was 110hp, and the other was 130hp naturally aspirated. I've got the part numbers I think for the builds, but most would unavailable now, cams and carbs and electric fuel pumps, everything else was sump plates, oil pump etc.
So it's not bad if it's pumping out 120hp.....although there is always room for more!!
I'll try and find the website I will be getting mine from eventually, they sell most of the parts for the group 2 5, and they are allegedly made to Renault sport original plans!!
Cheers

Simon

 

[mick]

that could be emulsion tube differences........check the old carb spec with the new one if you have it......i reckon 120bhp is brilliant from a 1.4 n/a ......if you spend £8-900 on 2 carbs and a manifold and can't get the emulsion tubes spot on your going to be well pissed!!

 

[mick]

the start of the torque curve is great but after 4500 your getting leaner or richer or the atomisation/quality seems to be effecting it......did Peter say anything about this?

 

[Mark]

the start of the torque curve is great but after 4500 your getting leaner or richer or the atomisation/quality seems to be effecting it......did Peter say anything about this?

I think it was a case of running out of options, it was the 10th power run and jet change with a tweak of the dizzy as well. It doesn't sound as if it is worth spending more money on carbs.

 

[mick]

Realistically the engine wont produce 100bhp(140bhp) per litre unless its at 8- 9000rpm so how much is left?
if you leave it the way it is it will certainly last longer.....i would'nt even go down the EFI route......thats at least another grand.
only option is to see if you can get the emulsion tube from the original carb..and compare it to what is in the new one.....if its the same you'll have to start modifying it ...trial and error....you might get a better torque curve which mean it will drive a whole lot better

 

[Number 11]

I've heard of 170 bhp from the atmo, built by the top man Sal Sacco... Here in the UK....
......

 

[Number 11]

Plus the Volvo 340 from 1979


Renault block and head.....