RPi logo
V8 engines and componentsdemonstratorssecial offersonline projectssite mapfrequently asked questionssecure orderingcontact

Customer comments section, 4 Wheel Drive (Range Rover, Land Rover & Discovery )
Engine upgrades, essentail chipping for efficiency, & other related upgrades!

Range Rover 'New' Range 'Rover 'Classic'
Land Rover 'Discovery' Land Rover. 'all others'

Range Rover New style (pre 2000 model)

Hello Chris,

Just to let you know the chip installation went smoothly and the results are very acceptable so far. I have not had the vehicle above 200 feet MSL as yet and really look forward to a trip up north in the near future. The rockers and shafts also went in without a hitch as did the pressure regulator. I am seeing a fuel consumption improvement of around 13% and unholy (by comparison with pre RPi stuff) flat land performance increase.

That's all for now

Best Regards,

Rob S
Hi Chris,

I have a 1997 Range Rover HSE here in Boston, USA. When I bought the car I was not happy with its slug-like performance and spent quite a lot of time researching the web for the best place to go for advice on how to improve the performance of the car.

Chris at RPI was spot on - thanks to him the car now sports a Tornado Chip, Magnecor Leads, and Aftermarket Shocks. The car now feels a LOT more responsive and handles much better. I could not be happier!!! My next planned mod will be superflare trumpets as the car needs to breather better before one considers doing any work on the engine. Great guys - great advice - what more could you ask for?


Hello Chris.
I just wanted to let you know, that I have ordered the parts for my engine swap,and aside from not specifying that I need the cam for a Gems block/Hotwire application, all went smooth.
Most importantly, I just wanted to say "Thank You" for your time and patience with me on this project. Your phone call a few weeks ago really surprised me. And your knowledge that you shared with me has been invaluable. That is Outstanding customer service ! I will e-mail you after the I install the engine, as I still need to buy the tornado chip.
Once again, thank you.( To Lisa as well ) I am looking forward to doing business with you again Sincerely, Robert


I got the chips and fitted them last night. I think the most difficult part of the process was getting the covers off the old chips as I was afraid of damaging the circuit board! The instructions are pretty simple - it makes it about as difficult as changing a plug! After I fitted the chips, the engine sounded a bit rough at first which I assume was down to the computer needing to re-learn the engine parameters, but this smoothed out after the first trip.

Once out on the road, initial results are very positive - I never saw 24 MPG on the trip computer before! Kick-down seems much more immediate, and acceleration more postive rather than the "oh, you want to go faster....? right... er... hang on... change down... wait a mo... here we go... any minute now... there you are...." that I was used to.

I'll be back in touch probably mid-August to arrange the LPG part - I don't have time to get this done before September since my weekends are fully booked.


LPG. On the spot customer comment.. !!

Everyone thought I was strange to convert my car, but I'm the one laughing all the way to the bank and to the gas refill station.

No queues there! And no-one profiteering, garage in Derby charging £1.99 a litre for unleaded!

Regards Gareth

(issue) Sept 2000. Petrol crisis.

The exhaust system came in the mail today,
One note of praise, it has been wonderful dealing with you and Chris on this restoration project, Thank you and next time I am in the UK we would like to visit your operation and maybe bring home a converted 110 with a 4.6.

Thank you

>DR Cantrell
6802 Halifax St..
San Diego California

Dear Chris

New Range Rover 4.0 (Gems) Re-chipped

Following my visit to you yesterday, I am happy to report the following: Consumption on the trip to you from home was 19mpg. My fuel consumption on the trip home was 22.3mpg. - You said it would improve. (these figures are according to the onboard computer)

The vehicle is also far more willing and pulls harder with less throttle I must congratulate you on your level of service offered to us.

The coffee and lolipop for the family was a nice touch. I am extremely suspicious about all in the motor trade and it was refreshing to find someone who tells it as it is. I look forward to a gas conversion to my vehicle and maybe a couple of other tweaks at the same time. Thank you again for your hospitality.

Best regards Rory Bostock

Unbelievably, From just a chip upgrade, you can expect an extra 15% economy -- 15% of the price of fuel is equal to 45 pence per gallon (UK) So what should you expect from further RPi Upgrades? It's well worth enquiring.

I went to RPi after 6 months researching LPG conversions for V8s. My 3 criteria were quality, value for money and fitness for purpose. RPi managed to score 4 out of 3 - 4 being exceptional customer service - in that despite my lobbing in several last minute requirements for handling improvements etc. they delivered on time to budget whilst coordinating the activities of 2 other companies e.g. a specialist in Sat Nav installations. The outcome is an HSE Range Rover which has the fuel costs of the average saloon, the practicality of an estate [no tanks in the boot yet a >>300 mile range] and road manners to shame some "sports" cars. So, if you like to have your automotive cake and eat it - with icing & cream too - the trip to their part of Norfolk is definitely worthwhile.

Ian Smith

More Gems Chipping Info "Click Here"

Range Rover 'Classic' Section.

Range Rover Optimax Upgrade

After having a good drive back to Northampton last night, the differences made by the chip became very apparent, and the car has been measurably improved in both performance and driveability.
Cheers, Bill Barclay. Scotland

I installed the new engine about 2.5 weeks ago. The difference between the 4.2 and 4.6 is like night and day, granted the 4.2 was pretty tired and neglected by the previous owner.

I shortened and polished the intake trumpets and had the distributor re-curved as well as all the performance items that RPI supplied. You can feel that the engine is breathing much better with the Stage 3 valves and the additional plennum volume added by the short trumpets. I went ahead and had all new valve seats installed and had then do a 3 angle grind like you recommended.

The engine has a very smooth idle. yet the torque band is much broader thanks to the RPI/Piper cam. Off line acceleration is fantastic and it feels like the engine will continue to pull until it runs out of road. I haven't done a 0 to 60 test, but it is on my list.

The Headman headers have not been installed as of yet, I needed to make sure everything was good to go. Even with all the performance upgrades, the 4.6 passed our smog test with flying colors. We thought it might run a little too lean due to the stock computer however, according to the high RPM part of the smog test the CO and HC are right on the mark though I am still thinking about the chip upgrade.

A quick run down of the items I purchased from RPI are as follows:
4.6 short block Performance cam and timing kit , Head rebuilt kit with Stage 3 valves Used rocker assembly One set of valve keepers Headers, not installed as of yet Gaskets

See the Smog test, "Click Here"

Items completed out here:
All new valve seats installed with 3 angle grind , Distributor re-curved
Intake trumpets shortened and polished High performance 8mm ignition cables Let me know if this is an option.

Sincere regards,
David Golumbic USA


Well got the Optimax chip in as you know, working splendidly.............then I received the exhaust, very pretty! Bolted on now and the old RR is a different beast, completely excellent. Great note and superb free flow, it feels superb.

How can I get a recommendation to you for your comments page, I am thrilled to bits! Many, many thanks, and my very best wishes to yourself and Lisa for the holidays,

(Denver, CO),

RR LWB w/ RPI 4.6L Phase 3 engine

Chris-- Just wanted to follow-up after receiving the engine and completing installation. Once the engine finally cleared customs 6 weeks ago... (after they just sat on it and never even opening the box) ... the mechanic had a few challenges with installation. The most unusual was that the output of the crankshaft had a pin and the corresponding flywheel did not... not sure what the resolution was with the local rover dealership, but I wouldn't be surprised if a grinder or a drill was involved. The rest of the engine installation went just fine. Along the way the injectors were cleaned, I added Headman headers (#39800) which are well constructed and cost around $120 plus $200 for a titanium finish ceramic coating. I love it when option cost more than the original part. ;^) Also had the lower intake manifold that you supplied port matched to the engine, upgraded to the Mallory Unalite distributor and Jacobs Electronics ignition, mean green gear reduction starter, Tornado chip, plus all the other things you usually do when you have the engine out of the car for the first time in 7 years of life.

As for the engine... I used the Crane cams break-in additive and Castrol straight 30wt oil. Initial burn in went perfect and after 20 minutes the car was ready for quick tour of the neighborhood. The engine runs fairly smooth at idle and appears to have a lot more power. I've been suffering with only partial throttle and a maximum of 3000 RPM until I get more miles on the engine and let the break-in finish. To date, I have 202 miles on the engine and drove it work for the first time today.

Once I get a couple of thousand miles on it, I'll report back with the seat-of-the-pant-feel with the WOT test. ;^)

Also, I'd like to thank both you and Lisa for all of your help during the question and answer phase of the engine quest. You both were great and very responsive to my questions and made the ~$7K purchase from overseas completely manageable. Your company did a great job setting expectations and delivering on your promises and I have only positive things to say about the experience. I especially appreciate your willingness to build me a "custom" engine (partway between long block and turn-key) and bundle all the parts so I wouldn't have to disassemble my current engine during the swap. I'll be happy to enthusiastically recommend RPI to my fellow rover buddies.

Thanks again,
Ron Story '95 RR LWB
w/ RPI 4.6L Phase 3 engine

Range Rover Weber Carb and (eventual) 3.9 Engine upgrade

Hi RPI genii!

Cam kit now in ancient 3.5 Rangie, along with the 500cfm weber you supplied a while back. So impressed with this engine, as it runs in it just gets better. Fabulous.

The 3.9 ran first turn! Smooth, and very lively. Haven't even been up in rpm or into secondaries yet, due running in. Only 100km so far, yet fuel gauge hardly moved. Very relaxing to drive, and having to take care as it builds speed so willingly.
New subject- just got sent flying solo in a helicopter this morning! If you ever visit Sydney come flying! I have shares in a Company with 4 IFR a/c, including a Saratoga, so it's a simple matter. Somehow I think an RPI light V8 would be just the go for a homebuilt helicopter.

Kind regards, Martin Geliot ( Australia).

Range Rover LSE 4.6 conversion In Sweden.

See how simple it all is, " Click"

Snow cool

I purchased a 4.6 long engine for a RR LSE. I have it properly installed now and I am very pleased. I have driven it approx. 3000 miles. Now all sorted. I want to share my experience with you

The 4.6 with its Tornado chip give magnificent performance to the vehicle. The torque (compared to the 4.2 I had) is impressive and sends off the machine to the excess of my expectations. I never though a Range Rover could perform like this. I have also noted a reduction in fuel consumption, at least at modest speeds. I am sending you two pictures , one at vacation for the RR) and one at work. Use them as you want. When pulling the trailer at around 100 kmph I ran the vehicle at 15 liters per 100 km.

Best regards, Per Nilsson

Racing 4.6 Range Rover in Barbados

hi chris just a short note from down here in the land of eternal sunshine and coconuts with rum in them . my 4.6 that you built for me two years ago is still going strong. by the way i am wheeling a fully rebuilt 1972 range rover , and it goes like a bat out of the tropics. .
Thanks, Marc Ward

(Quote from the UK Land Rover register)

From: "Peter BRADLEY"
Date: Thu, 15 Apr 1999 18:10:08 +0100
Subject: Re: Gas

A mate of mine just had his RR converted by RPI Engineering. The full conversion, (to Dual fuel remember, petrol or gas, it runs on both), was about 1200UKP.

However, whilst the motor was being tinkered with by *the* V8 experts, he decided to have it re-chipped, new performance cam, and new performance SS exhaust, all fitted at the same time. This little package brought the whole lot up to 2000UKP.

The performance enhancements actually *improve* fuel economy, and although the engine burns about the same mpg on gas as it does on petrol, gas is so much cheaper that he has calculated the RR is now returning the equivalent of 42mpg at current petrol costs! Much better than the Tdi he had previously.

In addition to this he says that it runs smoother and quieter on gas than petrol. In short he is delighted. I know of others around these parts (North Yorkshire) who have had Discos and RRs converted from Tdi to V8 so as to convert to gas. The thinking here is that you can currently sell a Tdi for decent money, and pick up a V8 relatively cheap. In a couple of years time you might not be able to give a Tdi away.

The government has promised to freeze the duty on gas whilst hiking up the duty on petrol and especially diesel. The major oil companies have plans for a major network of gas outlets.

check out:-

Further to my 4.6 upgrade

First I got to say that I had a great time at the MECC in Maastright.( me too) Hope you liked it as well. Learned a lot from you (again) ( no I just confirmed what you already suspected) and saw the stage 1 and 3 heads live which is completely different than seeing it on the website!! I also tried to push a dutch guy into buying a 4.6 from you in the process. Although I have the impression that the 4.6 is putting more stress on my gearbox than my old 3.5..... By the way the 4.6 is getting more loose now and is fun to drive. I sometimes just drive away in second gear if I wanna make a fast 'takeoff'.



Thanks for letting me buy one of your demonstrators last year. I have had the vehicle for a little over a year and it has been wonderful. In fact, I recently took it for its first MOT and no problems!
I have just fitted your A & R unit - it is early days, but I seem to be going further with no loss of power. Hills that were a problem before are easy now. Keep up the good work and let us have more innovation.
Stephen Whelan .


I don t know whether you will remember me, but I rang from Melbourne, Australia 2 weeks ago and you gave me some advice on my recent conversion to a 4.7Ltr V8 in my 87 Range Rover. Well the regulator arrived and we fitted it today, to say the car has been transformed is a monumental understatement, it's like having 4 extra cylinders! I just wanted to thank you very much for your spot on straight forward, honest, advice. As a member of the Range Rover Club in Australia and past treasurer I will be putting an article in the magazine which we send to clubs nationwide here. Once again thank you very much.


K. Rolston
Melbourne, Australia.

Land Rover Discovery Models

Optimax Chipping for efficiency

Thanks for the correcting me on the Optimax for the 95, 3.9, 5-speed U.S. Disco. The chip works far more than i expected. I have a Borla stainless steel cat back exhaust (free flow with a rumble). I port matched the intake to the heads, flowed the trumpet base to manifold. Increased the trumpet length by 1 1/2" (38.1mm).

Many thanks, for finding someone who knows their product and what we want.

Thanks again! Carl, California.

Robert Goodale Australia

 Off roading for sure. Chris,

I now have the carbie + manifold I purchased from you on the Rangie, and by and large it is performing well--mucking about with the float levels +offroad seats has improved its uphill response on slow climbs at low rev/low range. Although off-road (not fast rally racing like your Dubai correspondent) I think I would bet my life on the Strombergs rather than the Weber --on road it is veerrryy smooth!

Two questions.
{short description of image}How would you try to minimise it cutting out on extreme downhill inclines at low revs?

{short description of image}The key word here from you pics is ( extreme) you could run it duel fuel as lpg wont care if you turn it upside down
{short description of image} I am having trouble restarting (from hot), and I suspect fuel vaporization. I know this is Australia + summer+ + slow off-road stuff (where everything does get very hot), but it also happens on the bitumen as well eg stopping at a petrol station (as you do!), and then trying to restart. The Electrics are okay
{short description of image}I would be inclined disagree with your last comment, I suggest your spark quality is low, either due poor earth or tired starter drawing too much current when hot, or poor spark output due distributor condition and plug lead type.

Range Rover Discovery Chipping.

I've now had my Disco at SAC (www.steves.co.za) who must rate as the most reputable tuning house in SA:
Here are my findings as measured at the wheels with 2 wheel dyno by SAC on both occasions:
With 3.9 + Unichip + 245/70/16 tyres: 82KW @ 4300 / 250Nm @ 3300
With 4.6 +Unichip + tornado chip +245 / 75 (!!! NB !!!) / 16 tyres: 111Kw @ 4300 / 307Nm @ 3400 Above figures were measured at 1500m above sea level. SAC found the TORNADO was running a little lean at low RPM and a little rich at high RPM but acknowledged that it was one of the best chips they've come accross.
This (and timing) was corrected with the UNICHIP. Before they tuned it, it was idling rough, and backfiring on overrun. Now she idles smooth, and the backfiring is limited only to a very abrupt "parp" immediately after releasing the throttle - must be for less than 0.25 seconds. The rest of the overrun is clean. My conclusion is that I am very satisfied with the result and I feel I got my money's worth. PS: I'm already saving for a 5.2 for the HSE - yet to be purchased ;-) Kind regards Philip Lochner

South Africa.

Land Rover 'all models'.

Hi Chris, I'm Bart Callens from Tunesia.
I must say the 4.6 you delivered to me summer for my Defender 90 is great. I don't regret it I toke the 4.6 in stead of the 3.9. Now I have a question. I saw you have now dual chip ECU's.
Tunisia looks good.

This is the life, And with the Power and reliability of an RPi high torque engine, who could want more.

4*4 Convoy Off roading is so much fun

* Can I use one of these in my Defender 90 4.6 EFI (with tornado chip) ?

* What would be the benefits of a dual chip ECU ?

* What will it cost ?

* Can I replace the chip myself ?.


Bart Callens

The 4.6 Stage III we put into the 1995 NAS Defender 90 Station Wagon now has plenty of break in miles on it, and we took it to the track today. Stock 3.9 in this 90 ran 12.5 seconds 0-60 The 4.6 ran a best time of 7.78 seconds 0-60 this morning!


Owner of the D90 with the 4.6 called today to say how much he loved the truck, Said he towed is 26 boat home in 5th gear at about 85 mph, and could never tow the boat over 4th gear before. We have decided to keep ECR on the upper end of the RPI scale, so we will only be working with 4.6s and other performance mods, and some 3.9s. So we won't be buying in bulk, but will continue to do high end engines with you for a long time to come I think.

D90 Converted to 5.2 with RPi Engine installed by "ECR" in Main (USA)

Thought you would enjoy the positive feedback from the owner. Thanks,
Mike Smith "ECR"> >The engine is terrific, and the ride home was a blast. I have 650 miles >since I picked it up on Friday, and have changed the oil once. Thanks so >much for providing me with the most powerful D-90 in North America,


3.9 Land Rover Upgrade from a 2.6 6cyl petrol.

inquiry: Hi, just a "reccomendation" for you to print on your website! I've upgraded my Landrover S3 109 from a 2.6 6cyl petrol to a 3.9 V8 from you, and WOW! It's smoother, quieter (despite "sports" (very loud) exhaust) and pulls like a train in any gear! Considering the 6cyl needed new pistons (£1000+ of work) fitting a V8 has saved me money, as at least you can find parts for them

John U..

Chris, You are to be congratulated on the restoration of Fred's Land Rover.

The Web article is brilliant. By the way my ex MOD V8 that I bought off you last summer and that I installed with no difficulty in my 1982 Range Rover gets better everyday and runs as quiet as a sewing machine. It performs smoothly and quietly. So much so that I have ripped out the soundproofing so I can actually hear the engine. It is something of which I am very proud. Hope you don't mind me refering to RPI in my website. Regards Dave Lowe Derby.


Marc W. Peifer LWB 93 Landy 4.6 conversion

I would also like to inform you and your colleagues that the 4.6L that was installed in my '93 LWB is performing splendidly just as you said it would. I have several friends with Land Rovers that are quite envious, and are likely to be in contact with your company in the near future.

I can honestly say that it has been a pleasure to deal with RPI, and my smooth running Rover is testament to the fine work that you do. Please let me know if I can somehow express the appreciation for your 'living up to your end' of the bargain in delivering a true bolt-in long block; even my mechanic was surprised, and he is not easy to impress. Again thanks, and I will forward some action photos as soon as mud season is upon us here in Southeast Michigan. I can't wait... Very best regards,
Michigan USA.

Land Rover 101 (LPG and Petrol)

Chris, Just a brief note to say I have just returned from Spain with my 101FC with the new engine. It's a cracker and so smooth. We came over the Pyrenees via Andorra and the torque makes it simple. Many thanks for the short engine, bits and advice.

J. G.

A comment from a French customer ( 3.9 short engine and LPG Gas conversion.)

Other than that, well I have done just over 10,000 miles so far and nothing tomention, other than the fact that my LPG conversion has almost paid for itself! In another 10.000 it will also pay for the new block.

Anyhow, I hope business is well with you,


(Range Rover 3.5 to 4.6 conversion) (Flapper type) with Evo 4 computer upgrad. to complete.

Dear Chris,
I've been to Power Engineering in Uxbridge today, to say my car has been transformed is a massive understatement. Both Mark and Merv (of Power Engineering) were most helpful, there understanding of things electrical and ability to put this in 'laymans' terms is wonderful. For any prospective purchasers of your 4.6 conversion if keeping the old flapper type injection system, I cannot stress how much more drivable this ECU conversion makes the engine. It was a joy to drive home today - so smooth and was just what I imagined the conversion to be like.

Your Kind comments are always appreciated "Thanks"
{short description of image}
Your slave to this Web-site !!

Prices do not include local EU.Tax.(VAT).
Prices & stock are subject to change without notice. Information and advice, as always, is free.

RPi logo top of page back home

© Copyright RPi Engineering 1999. contact: using our new form
Wayside Garage, Holt Road, Horsford, Norwich, Norfolk, NR10 3EE, United Kingdom
Tel +44 (0)1603 891209 Fax +44 (0)1603 890330

Site design by astutech