Interesting conversion, 1995 Skyline R33 GTR

[MobileLPG]

Hi All,

I thought I would share my latest 'in my spare time' during the summer conversion with you.
It is a Nissan Skyline R33 GTR running somewhere around 450bhp (last dyno showed 400bhp and it has been modified a lot more since then, however as I mapped the car myself on petrol using a Power FC and LPG on the road I have never dyno'd it.....to be honest I am not a fan of screaming the t**s off an engine while it sits there going nowhere so I tend to avoid dyno's anyway.

She isn't the nicest example on the road but I bought it last year as a project as I have always been a fan of the Skyline GTR's.
Here she is the day I bought her, unfortunately she had 6 months of being owned by a young lad who liked going to cruises and had the obligatory shopping list and decals etc-


I tidied her up, removed the stickers, had a load of bodywork carried out and then debated whether to convert a weekend toy to run on LPG or not.
Then came the standard purists remarks of "If you cant afford to run it then why buy it" etc, I decided that although it is a weekend toy, I fancied the challenge and why run it on petrol when I can run it on LPG.

The main issues with converting this car were going to be-
1 - Due to the layout of the twin turbo inline 6 engine there was no room under the bonnet.
2 - 6 individual throttle bodies positioned right against the cylinder head.
3 - The tank, the GTR has the petrol tank and battery behind the rear seats and a very short boot with only a small space saver wheel well.
4 - Piping, the 4 wheel drive system is very compact so running the piping with adequate room would not be simple.
5 - Filler, a towbar bracket isn't an option, a hole in the quarter panel was a definite no.
6 - Power, with somewhere around 450bhp and a rev limit of 8,400rpm which LPG system to use.

I decided on a BRC Sequent system, I have fitted many different systems in the past and used various systems on my own cars, but in business it has always been my experience that the BRC system is a very solid reliable system (I'm not saying other systems are not as good but I prefer the BRC system as a whole package)
Then came the decision on the tank, a cylinder was not an option as I still wanted to use a little boot space and a cylinder would take up all of the small boot, so a toroidal with a slightly raised floor was the only real option.
The filler I really wanted to be discrete and hate the idea of cutting a hole in the quarter panel, I then found whilst looking around the car that the rear number plate is fitted on a hinged bracket that flips up and is held closed by a small 10mm bolt, decision made, hide the filler behind the number plate and ditch the 10mm bolt in favour of a strong magnet to allow the number plate to be pulled up out of the way for filling with LPG.

Here is the engine bay before I started...ignore the gold engine covers, another leftover from the previous owner.


After studying the engine bay to work out the location of everything I worked out where everything would go, the plenum and throttle bodies would need to come off to drill the 'balancer' so I decided to ditch the IACV system below the plenum and fit a remote oil filter and Accusump, this would give me literally just enough room to fit the BRC Genius MAX regulator below the plenum, fitting would have to be accurate to within a few millimetres or the plenum and fuel pipes would be in the way.

Heres a few pictures of the strip down-






This the balancer that fits between the throttle bodies and the head, the injector nozzles have to go into here... not a lot of room for error.


Engine with balancer removed and new HKS metal gaskes fitted-


Balancer refitted with nozzles fitted-




I got a little bit lazy with the pictures so not a lot to show for the regulator fitting but here it is fitted, the shut off valve is fitted very tight into the near corner on the left (you can just see the orange top) and the throttle bodies are sat back in place-


Plenum painted and refitted, glad to say the regulator sits nicely in its place and just about clears everything with enough room to alow the engine to move without making any contact-


Wheel well painted in Por-15 before fitting the tank as Japanese cars of this era are not the best at keeping rust at bay, I have Por-15'd the whole underneath so had this already to hand-


Once again not really anything to show as I got stuck in and forgot to take pictures, but as you can see I used 8mm Faro pipe which made routing to the front a lot easier than expected..although there were few real tight areas that made feeding it through interesting, certainly would have been more comfortable if I had moved the car over onto the concrete section so I didn't have gravel digging into me-


The wiring was the next part, I really wanted to keep the wiring tidy so decided to mount the ECU inside the car, I had removed all the aircon from the vehicle anyway so had a nice large hole in the bulkhead with a grommet to feed the wiring loom through, in this picture you can see the new loom running across the bulkhead-


By having the ECU behind the dash on the passenger side, the main petrol ECU is also in the passenger side kick panel so all the wiring could be shortened by a huge amount meaning everything could be neatly hidden away, the picture shows the wiring coming through the bulkhead and you can see the original petrol ecu (well a Power FC) on the left kick panel-


Fitting the injectors was a real nightmare, the 6 individual throttle bodies have 3 throttle linkages joining to the throttle cable and arm, siting the injectors was awkward as everywhere they went either they or the pipes would foul against the linkages, I have managed to fit them with the piping just clearing the linkages.... I would have prefferred to have the injectors in a 'neater' location but until I think of a neater solution they are currently fixed into position with the piping as short as is possible, all equal length and have just enough clearance for the throttle linkages to move through the full travel-


Unfortunately as it came close to firing her up on gas I cracked on with it and didn't really take many pictures, now that she is parked up for the winter I painted the engine covers so found a picture showing the injectors piped up, its not a good quality pic but you can see the reg squeezed in below the plenum and the injectors-


I have been busy so haven't found the time yet to mount the filler or find a 'tidier' way to mount the injectors and clear the throttle bodies, and she is now in winter storage so those jobs will be for next summer.
I temporarily fitted a filler so the tank could be filled, and got on with the calibration and mapping, the car switches to LPG extremely smoothly and cruises beatifully so time for some mapping, I always fit a wideband sensor and gauge into any of my cars that I tune so that certainly helps with the mapping, also the beauty of the power FC petrol ECU is I am able to plug in my toughbook and log all sensors so after a mapping session I can then sit in comfort in my basement/office and look over all the data and find any points that can be tweaked to improve the map, until I am happy that all areas of the map are as perfect as I can get them, I run a slightly lower boost setting when running on LPG.
I am happy to say that she runs beatifully on gas and happily revs all the way to 7,000rpm on LPG... I do not rev higher than this as the RB26DETT engine likes to spin No6 big end bearing if the revs are regularly taken above 7,500rpm, for this reason in the Power FC I have set the rev limit down to 7,200rpm.
On a drive to Southampton and back I was able to average 19mpg cruising at a good pace and a few spirited runs on a few stretches of suitable road.

You don't often get to a Skyline filling up with LPG so here's a rare picture-


Hopefully in the summer I will get time to play with her some more and will update this thread.
Edward.

[dannyf]

I do like the R33 one of the work shop boys has one nice cars but they do like a drink if you drive them hard like any turbo car
nice to see one on LPG
I would not mind a R32 or R33 my self

[j33myb]

This is a cracking thread, thanks for sharing.

[MobileLPG]

Hi Danny,

A Skyline GTR has always been one of those cars I have wanted but with 4 kids and a wife I have to have a practical car... hence the Volvo, but then because it is a tuned T5 I can still have fun when it is just me on my own.
In 2009 my wife informed me that somehow she was pregnant so that meant the Volvo was going to be unsuitable as a family car, even with the seven seat conversion I had in there... I done her a deal, I'll get her a people carrier as long as I can have a toy, and that was it, she got a Voyager and I got a Skyline.
The problem now is I bought this car intending to track it every now and then, but now I really like the idea of having a stripped out R32 on LPG for track days and continuing the restoration of this one....... they are very addictive

J33myb - Thanks for the comments and glad you enjoyed reading it, when I get time next year I will update with pictures of the filler location etc.

Edward.

[Gilbertd]

certainly would have been more comfortable if I had moved the car over onto the concrete section so I didn't have gravel digging into me-

No, you got it right, laying under a car on a flat surface is seriously dangerous. Many years ago, I built a kit car for my wife (of the time) and, at that time, my driveway was covered in pea gravel which wasn't particularly comfortable to lay on. So, to make laying underneath a bit more comfortable, I had a huge sheet of thick cardboard that I would lay on. One summers day (yes, it was so long ago we had real summers then) I was outside offering up the engine and gearbox to the chassis. Amongst many things I had acquired to go in the build, were a big box of stainless bolts and nylock nuts and I decided to use them on the gearbox mounts. Unfortunately the holes in the chassis weren't big enough so I drilled them out and then proceeded to lay underneath bolting everything together. Now I did say it was summer so I was working without a shirt but later in the day, it started to get a bit chilly. It did seem a bit odd that my teeshirt seemed to be snagging on my right shoulder when I put it on, but I didn't give it any more though. Not until I got in the shower that is. Summoning my wife to investigate, she informed me that most of the swarf from drilling out the holes was now embedded in my back. She removed as much of it as she could with a pair of tweezers but suggested a visit to the local medical centre might not be a bad idea.

So the following day I'm in the medical centre having the remainder dug out and it is suggested that a tetanus jab might be a good idea. Now despite having an aversion to bits of surgical steel being deliberately inserted into my body, I agreed that maybe they were right. So, after warning the nurse that I was a grade one wimp when it came to injections, I got the jab. I was then told that this was only the first of a course of 3 and I should make an appointment for the next one on my way out. I got to reception and told the girl I needed to make an appointment for a second tetanus jab. She consulted the diary, looked up from it's pages and said "Do you feel alright?". I remember saying "no" and that was the last I remember until I woke up on a trolley in the local hospital with an almighty headache. Seems that I had fainted and on the way down had hit the top of my head on the corner of a steel radiator. Four stitches in my scalp, an x-ray and 24 hours observation in hospital (in a small ward full of other blokes who had all done something equally stupid) later, I went home and threw away the cardboard. Had I been laying on the pea gravel, the swarf wouldn't have been pressed into my back!

[dannyf]

I have the Zafira for the car to pop around it dose 330bhp and upsets boy racers
I might give that to the mrs with about 240bhp and look at a sky line
for my self as you can pick them up cheap now days a nice R33 Gtr-v would be nice as its got the latter spec diff
and they sound Evil

I would put a flip down rear mumber plate and mount the LPG filler under that

[mat_fenwick]

at Gilbertd! Although any surface would be better than mud, which is all we have round here at the moment (we live halfway up a forest track).

Very interesting thread, I shall have to use this as an example the next time someone says you can't fit LPG to a performance car!

[MobileLPG]

Hi Danny,

This is the V-Spec with the electronic rear diff, it can be tricky finding a genuine V-Spec as everyone puts the 'V-Spec' sticker on the boot, and the electronic rear diff was also an optional extra, I found a website where you can put in the VIN number and it tells you the full spec of the car, also if there is a W in (IIRC) the 5th character of the VIN then it is a genuine V-Spec.
I couldn't honestly say how much of a difference it makes having the electronic diff as I haven't driven a non V-Spec and I have fitted a 'Grid Dancer' that gives me full control of the 4WD system which when in RWD mode seems to disable the diff as well.

Gilbert,
That sounds painful, I have made the silly mistake of grinding underneath a car with no goggles on and getting fragments in my eyes, now that was painful.....in the end I had to go to hospital and get them removed, not nice when they aim at your eye with a long thin metal probe and literally flick the metal parts out.
Actually I should steer clear of grinders, a few years ago I had a job booked in Lake Tahoe, California. 2 weeks fully paid to go over and convert a customers car from Auto to manual and was really looking forward to it...that was until a few days before flying out I ground the end of my finger clean off whilst cleaning up some metal LOL luckily it wasn't as bad as it first appeared so I was still able to go over there and do the work but it certainly is up there with some of the stupidest things I have ever done working on a car

Mat,
It is surprising how many people are shocked when you tell them a performance car can be converted to LPG, a few people have told me they would love an Impreza but wouldn't have one because it can't be converted, then they are amazed when you tell them the Impreza actually runs better on LPG than it does on petrol.

Edward.

I have the Zafira for the car to pop around it dose 330bhp and upsets boy racers
I might give that to the mrs with about 240bhp and look at a sky line
for my self as you can pick them up cheap now days a nice R33 Gtr-v would be nice as its got the latter spec diff
and they sound Evil

I would put a flip down rear mumber plate and mount the LPG filler under that

[Tubbs]

Thats a nice little thread edward. Its funny i did one maybe 7 years ago on an earlier type romano system. I came to the same conclusion with the reducer. Single injectors helped a lot on the installation, as you said they are a pig for injector placement. Hey it looks like you are at the refuel site on stafford park, somewhere i frequent also. But live in ludlow so more often than not its the one at autogas developments at brimfield. So where abouts in telford are you ?

[MobileLPG]

Hi Tubbs,

That's very interesting, on all the owners clubs and forums no one knows of any other GTR with the RB26DETT engine being converted to gas, plenty of the GTS-T's with the RB25DET, but not a GTR.
If it was a GTR you converted I would be very interested in more details? especially if the Romano system was able to cope with it, these engines are rated at 280bhp standard but only due the japanese 'gentlemans agreement' they are actually around 310 as standard and that is restricted with a restrictor in the boost solenoid pipe, remove that and give it a free flowing exhaust and you are upto 370-380bhp at 1bar instantly.
Well spotted yes that is Stafford Park, we may have even passed each other as when I was using the LPG Connect for work I literally filled up there every single day.

I quite often pass through Ludlow so will have to drop in one day and say hi

Edward.

Thats a nice little thread edward. Its funny i did one maybe 7 years ago on an earlier type romano system. I came to the same conclusion with the reducer. Single injectors helped a lot on the installation, as you said they are a pig for injector placement. Hey it looks like you are at the refuel site on stafford park, somewhere i frequent also. But live in ludlow so more often than not its the one at autogas developments at brimfield. So where abouts in telford are you ?

[mat_fenwick]

Just out of interest, I assume you're using the VW diesel for work now - do you find that cheaper to run or is there more to it than that? My only gripe with using LPG when doing a lot of miles is the number of times you have to fill up, but that's because my LPG tanks are little more than half the petrol tank capacity.

[MobileLPG]

Hi Mat,

Yes I am currently using the VW Caddy, unfortunately it costs me around £5 per week more runing on diesel.
The Connect was a great van and in 3 years I covered 157,000 miles with not one single issue...brilliant van but very weak, with all the equipment and parts I carry my van is always very heavily loaded and that poor little 115bhp 1.8 litre struggled to keep its own momentum let alone pull up a hill, I was averaging around 22mpg, the tank is only 45 litres so multiple fillups most days and even though I have all the parts to put a bigger tank in the van....everytime I went to fit it I couldn't see how I could make room inside for it.
The Caddy is a great van, I have fitted the gearbox from a Golf GT TDI engine into it so I now have 6 gears which does helps with economy, the main bonus is that it pulls up hills easily, but it really does kill me after all these years to now have to hand over £100 every time I fill up
The turning point for me and the poor little Connects downfall was on my way to a job in Cirencester I hit the steep section of the A417 and with my foot to the floor in 2nd gear, I got overtaken by a Renault lorry, complete with loaded trailer LOL
If the Connect had the 2.3 engine for the extra torque it would have been perfect on gas.

Hope this helps,
Edward.

Just out of interest, I assume you're using the VW diesel for work now - do you find that cheaper to run or is there more to it than that? My only gripe with using LPG when doing a lot of miles is the number of times you have to fill up, but that's because my LPG tanks are little more than half the petrol tank capacity.

[MobileLPG]

Hi,

I just done some more calculations on my diesel v's LPG costs and it actually appears I am spending around £10-£12 a week more on diesel.
My original calculations were based around me getting 45mpg out of my van, however since getting it racked out and being able to put the rest of my kit in there I am averaging 40mpg.


Edward.

[Gilbertd]

Which ties in nicely with some calculations that were done a few months ago comparing riunning costs of an Astra van. LPG was the cheapest, with diesel a close second (I think it was something like 1p per mile) and petrol way more expensive.

[MobileLPG]

Well my calculations are-
I average 1500 miles a week.

LPG Connect -- 1500 miles @ 22mpg, 309 litres at 70p per litre £216
VW Caddy -- 1500 miles @ 40mpg, 170 litres at £1.38 per litre £235

The figures could be made to swing even more in the LPG's favour as I can get LPG for around 65p per litre, and the normal price for diesel at most places is actually more like £1.42.
I do kind of regret getting the diesel but unfortunately small van's always come with either diesel engines or weak tiny petrol engines, I was going to go the route of putting a bigger engine in the Connect (ST170 or Focus ST) but could never get enough time to be able to take the van off the road for long enough.

Edward.

Which ties in nicely with some calculations that were done a few months ago comparing riunning costs of an Astra van. LPG was the cheapest, with diesel a close second (I think it was something like 1p per mile) and petrol way more expensive.

[Tubbs]

Edward, I've only just picked this back up. Tbh I'm not overly sure which engine it was...he was a Dutch IT engineer if my memory serves me correctly. It went well on a Romano system I have to say. Quite helpful having the separate injectors as they are a lot easier in certain scenarios. If you are ever in Ludlow feel free to give me a bell.

[Rangeroverrich]

Hello mate, I have just emailed you (richard from chichester) before finding this thread, I had an r33 m reg a few years back and it was the best car I ever had, after having owned many many fast sports/super cars and driving the likes of ferrari's around race tracks http://www.youtube.com/watch?v=zQPYExumEGg I can still say my skyline was one of the best, mine was a single turbo automatic as I can only drive autos legally (if you click the video you'll see why!) but it would still take anything off the lights being rwd it was great fun too going round the roundabouts with the tail out (on private roads only it even used to beat the manual skylines as it's one of the only auto's that is faster than the manual, a great car and I was very sad to see it go, although I thought about it I never got it lpg'd as it seemed ok on petrol for an auto 2.5 turbo, mind you petrol was under a pound a litre then! a wolf in sheeps clothing!! if yours was auto I'd be trying to buy it off you! now I have the range rover with lpg that has never worked since we had it and I need to get it sorted!!

[MobileLPG]

Hi Richie,

I was originally looking t buying a late model R34 GTT but couldn't resist the GTR, funny that you should reply to this thread now as I finally bought it out of winter storage at the weekend and drove it...I'd forgotten how much I loved driving it
I just watched a few of your videos!! Amazing, I think you could teach Jeremy Clarkson a thing or 2 about changing a Ford Transit door.

Regards,
Edward.

P.S I am emailing you a wiring diagram for your system which may help you out a little for now.

[Rangeroverrich]

lovely thanks, although wiring isn't one of my strong points! hopefully I will make a little bit of sense from it though!!! thanks for the help mate, I'd rather pay you to sort it for me! lets see how quick a skyline can get down south and how little gas it uses!!! haha