Newbie here. Stag or Prins on RangeRover 4.2 Supercharged

[samanthacoolbeans]

I'm currently looking to convert my 2007 RangeRover Sport 4.2 Supercharged.

So far i have gotten quotes of £2k+vat from Profess Autogas in S.Wales for a Stag install and also from a very local (to me) specialist called Autotech (based in Ripley) who have quoted me £2,300+vat for a Prins based system.

I like the idea that Profess only do high quality installations, and the fact they offer a 'remote service' feature so they can dial into your car and tweak things from anywhere in the world if needed. They also said that my car 'converts really well'. I don't like the idea that they are based over 150miles away from me incase there is a fault i need to rectify.

Autotech are appealing to me because they are only a 10minute drive away, and after a chat to the owner on the phone the other day he sounds very knowledgeable. The downside is that it will require a £140 service each year.

Im such a newbie to all of this so i don't know if these systems are reliable or if I'm just being taken in by marketing spin. Both companies have said it will take around 4 days to install so they are not rushing the conversion which I'm happy about.
Please could i have some independent advice?

Thanks Samantha x

[Tubbs]

I think you may well be taken in by marketing spin. Profess seem to be charging more and the done on a day thing seems to have been dropped.
The prins system is good. But perhaps not as technologically advanced as other systems on the market. And they seem to turn out lower economy figures than other systems.
Don't be taken in by the remote tuning thing. It rarely works. An installers tuning skill is a lot more to do with hearing / feeling what's going on. Rather than just throwing figures into a computer.
I'm not really impartial though. I am a pro installer who charges £1550 + vat for a supercharged R/R sport.
That's with a multipoint flashlube system. And a fuel return. I like to spend a week on them though personally.

[Bulldoggy]

I have a prins system fitted to my Lexus If I had to go again I would have probably gone for something different after reading the posts on here. I had it fitted by autech as they are just round the corner and sell gas as cheap as asda in derby. I had mine fitted for about 26 mnths and it developed a fault which turned out to be the ecu.

Autotech diagnosed and replaced at cost. The chap who runs it is very knowledgeable but be prepared to drool a lot if you go in there they have a dyno and some of the cars I've seen make me wish I was very wealthy.

All I can suggest is you do a lot of research and at the end of the day way up the pro's and cons of cost versus convenience.

[samanthacoolbeans]

thanks guys, So what is the best system to go for? assume that money no object, What would be the best for this car?

I think the Profess is a no-go for me just because of the distance i would have to travel for any faults.
Autotech are local but the most expensive.

gaaaaah i don't know what to do because i have no idea what any of these systems are like for reliability or functionality. its soooo confusing.

x

[samanthacoolbeans]

also why is the prins system not great? Could you point me to some of the offending posts? I've done searches on here but there are just so many results to trawl through.

x

[Brian_H]

This is the main reason for people not liking Prins

http://www.lpgforum.co.uk/viewtopic.php?f=28&t=12603

[samanthacoolbeans]

Ok I've just read that thread and now I'm really confused..

The key points I took from that thread:

Prins systems are expensive compared to other installations.
On the other hand Ive seen advice that I shouldn't buy a cheap system, I should get the best I can afford.

The Prins injectors are built for longevity, however they are an old design and are much larger than other brands. The Prins injectors seem to be well made and nobody disputes this.

The Prins ECU will only work with the aforementioned injectors, and ECU adjustment is not as technical as other ECU's.

Prins injectors are large and might make the installation look untidy.

The reason I'm confused is that it sounds to me as though Prins like to control a lot of the conversion process, I don't necessarily think this a bad thing if they have a solid and reliable product.
But the weak link in the chain sounds like the ECU. It sounds like this is susceptible to voltage spikes which sounds worrying.

In my heart I would love to support a local business, not just because it's easier for me, but also because if it does become faulty i can go and knock on a physical door easily too.

I've had a look under my bonnet and there looks like there's loads of room to put things, does the Prins system install cleanly on a 4.2 supercharged Range Rover or not?

Thank you so much for all your help everyone x

[Brian_H]

Its got more to do with the first post in that thread - fewer people work on Prins systems as they keep more info to themselves and their authorised dealers compared to other systems. This may or may not matter to you but it would be unwise to go for Prins if you only have one dealer available locally in the event you have issues with it. This could be more important in a couple of years time if you have an issue as your local firm may not still be there for example.

[Tubbs]

Let alone the the ally casting in the reducer going pourous. Well done on you for supporting us local small buisinesses though.

[samanthacoolbeans]

Let alone the the ally casting in the reducer going pourous. Well done on you for supporting us local small buisinesses though.

I'm really sorry for sounding dumb, but what does that mean? Can you explain it like I'm 5years old.

When I first thought about getting an LPG conversion I thought it was a simple thing but this is starting to totally scare me off hearing all these technical terms.

[Tubbs]

Prins had a lot of problems with the actual casing on the reducers leaking water into the gas. And gas into the water. Which can cause a lot of issues with the cars cooling system. Including belief that the head gasket has gone.
I presume they have addressed the problem by now.

[rossko]

First up; accept that the supercharged 4.2 is demanding. There is no cheap way to convert it.

Has anyone tried to sell you a valve lube system yet? They jolly well should be!

"The Prins injectors are built for longevity, however they are an old design and are much larger than other brands."
Old design = effective and has needed no development. (In truth there have been detail changes over the years) Key question - will they work on the s/c?
Much larger = about 10mm longer then some, about the same as many others. Do you care? It's under the bonnet. Key question - have others already fitted to them to the s/c?

"The Prins ECU will only work with the aforementioned injectors, and ECU adjustment is not as technical as other ECU's."
It doesn't need to be - because of the injector choice, there is little fiddling to make it work with non-linear injectors. Key question - have others fitted it to the s/c with sucess? That applies to other brands too, of course.

Note that almost all UK Prins experience is with the original VSI model, there are newer VSI-2 systems that are a more sophisticated follow on for more sophisticated cars. Not necessary here, this is more of a brute strength than a finesse task.

"Prins systems are expensive compared to other installations."
Yes. Range Rovers are expensive compared to other cars. They do not all perform the same. Having said that, of course Prins is not the only system that can me made to work properly here. You pay for the longevity - so this a decision for the owner "how long am I keeping it". You (should be) paying as much for the installers skills, equipment cost should not be a huge factor.

"But the weak link in the chain sounds like the ECU. It sounds like this is susceptible to voltage spikes which sounds worrying."
What makes you think that? I've replaced two in the last decade - one was indeed fried, by battery reverse connection. So was every other ECU in the Jeep!

"Prins had a lot of problems with the actual casing on the reducers leaking water into the gas."
Not the castings - gasket issue, redesign some 5 years ago completely eliminated the offending gasket. I don't think I'd call it "a lot" though; I've seen BRC and OMVL systems of that age with exact same failure mode too.

"fewer people work on Prins systems as they keep more info to themselves and their authorised dealers compared to other systems."
What info would you like that hasn't been made available somewhere? What parts would you like that are not readily available?
More people do work on Stag, but thats nothing to do with their open information approach - it's because it gets bundled with cheap components.

None of which makes your decision easier. Don't be put off Prins. Don't feel you have to have to have Prins, there are equally capable systems, though few of proven longevity.

Much more important is finding a competent installer, this is a demanding job and out of the ordinary eurobox comfort zone.

[andy evans autogas]

I personally wouldn't recommend getting a 4.2 supercharged range rover converted due to the fact that no amount of valve lube will stop valve seat recession and you will be into new seats and valves within 30k at a cost of around £3500 you will also end up with engine management problems. There are very few systems that will run these right without engine management problems but the one that I used is no longer available. I can only speak from real experience as in the past month I have had to remove an AEB based EOBD system from one of these that had only been professionally fitted for less than a year and caused lots of problems with the fuel management system this was also fitted with a fuel return.
I do have photos of the installation that I've just taken out but I don't think it's fair to post them on here.
I as a professional UKLPG approved installer have stopped converting these cars for at least the last 3yrs.
Andy

[samanthacoolbeans]

Rossko, thanks for such comprehensive comments.

I think the question I need to ask the Prins installer is How many RR sport 4.2L supercharge conversions has he done, Would you agree?

Thanks Samantha x

[samanthacoolbeans]

@Andy Evans

Will VSR occur even though the installer states that he will install a Valvelube system?
This installer also mentioned the Valvelube system was superior to many others including the Flashlube system.

How come some installers say 'No Probs' when I mention what car it's for when you say it shouldn't be done?
What should I do? X

[andy evans autogas]

A valve lube system will slow down the procces of VSR but won't stop it. Some installers just want your money here is one of the ones I've done this also suffered with VSR but after new hardened seats & valves where fitted ran 100% perfect with no engine management issues. http://youtu.be/9yieE7tWtfk
The system I fitted to this one is no longer available and I have stopped converting these cars. I DON'T want your money but also I don't want to be saying "I told you so"
Have a look here and the follow up from it.
http://www.lpgforum.co.uk/viewtopic.php ... percharged
Andy

[Tubbs]

The si electronik sequential units seem to be working on these. Unfortunately you have to fit 2.
I know of 3 that are running well into the 50/60k mark.

[samanthacoolbeans]

So the latest...

I have decided to forget the Profess conversion in South Wales, purely because of the distance I would have to travel if a fault developed.

I called up my local converter AutoTech in Ripley an spoke to Kevin, I asked him how many successful conversions he has done to Range Rover 4.2 S/C's and he told me he has done around 20 and none of them have ever had VSR issues (or any other issues for that matter).
He went on to explain that the Prins system is probably one of the most reliable on the market and there are quite a few other manufacturers that imitate the Prins design. He also told me that Kaihin also make injectors for Formula1 teams so they have quality and pedigree.

I asked him why his conversion cost of £2300+vat was the most expensive and he stood by his belief that he simply does quality conversions and that one has to pay for this sort of quality. No discounts are available an no concessions are to be made, the price is the price and if I want the conversion that is what I have to pay.

I don't mind paying more but I just want to be sure what he is saying isn't bullshit, after all, I do not know this industry, his company, the quality of his previous work or anything.

I'm trusting you guys on here to be impartial and tell me if you think that this deal sounds fair. If it does I'm going to book the conversion for a couple of weeks.

Thanks Samantha x

[Bulldoggy]

Samantha if you have any doubts about Kevin pop in and see him and his set up.He's a nice bloke who will explain everything and you can have a look round. He has a few racing cars that he sets up for clients and I believe he runs a couple of Range rovers that have been converted.

His place is behind Zycomm, you have to turn before you get to Zycomm on to a housing estate, That's if your coming from the Island at sainsburys.

hth Richard.

[Morat]

Small world, I buy our work radios from Zycomm