Fiat "short" 5th gear

[MikeP]

Hi All, Does anyone have have Fiat details of this conversion ie part numbers or similar. I've asked at our local main dealer (County Motors Carlisle) but their man hadn't heard of it. Thinking of having it fitted to my 2003 Autotrail Cheyenne. All comments welcomed Mike P

[Don Madge]

Mike, There was a thread on the forum in Nov. 05 about the lower 5th which you might find interesting at http://tinyurl.com/lxk28 Don

[Simon]

Essanjay in Dorset do this conversion. They will probably be able to give you the part number. They advertise in MMM.

[enodreven]

Hi, From all that i have read about this i think i would go for the re-chipping subject to warrantee conditions, as i think that the lower gearing will have an affect on your overall fuel consumption and there could be an engine noise problem as it will be reving higher. I beleive that most insurance companies will cover you after the vehicle has been re-chipped and from what people have said at no increased costs. The only problem appears to be the Fiat warrantee and if your vehicle is still covered by this then it appears you need to be very careful as apprantly they will be able to tell if you have had a chip fitted even if you remove it before making any warrantee claims as from what i have read the ECU will record the changes ? Hope that helps Brian

[Terrytraveller]

Hi Brian, Just a thought, the faster mine revs the quieter the engine is! 2ltr HDi power plant. Regards Terry

[enodreven]

Hi, I will try driving in 1st gear that should keep it quite ?lol

[RonB]

I have owned two motorhomes fitted with the Fiat 'short-fifth' gear. Neither had/have a noise problem or used more fuel. The latter I put down to not having to use fourth as often, or at such high revs, as previously. Our first van was modified by Essenjay and our present Burstner came with it fitted as standard. Burstner now fit this gear as standard all their models above 3500kg I believe. In my experience, and I am not deaf!, this gear has all the advantages and none of the hurdles presented by chipping. Have fun.

[enodreven]

Hi, I beleive the modification increases the engine revs by approximatly 700 RPM at 70 MPH, If that figure is correct then i think that it speaks for its self, as we are not always going up hill ?? it just feels like it ? lol

[RonB]

I think it's nearer 500 revs, but no matter. However, the main point is I'm talking from practical experience, not theory and speculation. After all bee's can't fly in theory can they. It's also worth bearing in mind that the heavier the motorhome is the more benefit a short-fifth, or 'chipping' come to that, will be. I certainly don't recommend it for something like a panel van conversion, they simply don't need it.

[enodreven]

Hi, On the Bee thing, It takes fuel to turn an engine, and i again think taking your pratical knowledge and experiance the extra 500 rpm has to come from somewhere, as it certainly dosen't come from nothing ? as for the extra noise, i really find it difefcult to beleive that its possible to inrease the RPM by 500 and not increase the decibel rating of the engine, whether this can be heard through the sound proofing is another question ?

[dickyc2]

8-) My experiance as a motorhome owner is very little, but as a mechanic it's vast, a shorter 5th gear will in some instances decrease engine noise through natural harmonics( engine mounts and natural vibrations), but also it will increase fuel economy, because you will use less throttle hence less fuel, i'm cosidering a shorter 5th for my kon-tiki, because below 50mph it has about as much perfomance as a milk float.

[Dave Newell]

[QUOTE]Simon - 2006-08-25 9:13 PM Essanjay in Dorset do this conversion. They will probably be able to give you the part number. They advertise in MMM.[/QUOTE] It's extremely unlikely that Essanjay will give you the part numbers for the lower fifth gear. I had a customer last year who wanted me to carry out this mod but I couldn't find a Fiat dealer who could sort out the right part numbers. I phoned Steve at Essanjay but they were very cagey about it. Can't say I blame them as they seem to be the only outfit who can/will do this mod! The lower fifth gear can reduce noise as Dicky says by altering the frequency of noise. It can improve fuel consumption by putting the engine into a more efficient rev range at 50+ MPH as this is where the problem starts. At 50 MPH the engine is barely above tickover and the turbo isn't spinning fast enough to do any good. Upping the revs by 500 means more air flow through the engine and therefore a higher spin at the turbo and more boost. If an an engine is running more efficiently, or at a more efficient speed it will use less fuel for the same amount of work. D.