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ghettofabulous intercooler installation


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following on from a brief discussion in a thread inhe international forum about diesels, here's some pics of the intercooler in installed over the last couple of days. its raining heavily again, so i'm a bit bored.

i post i here, becuase whilst its in place its not plumbed in yet and i might need some help :D

tech content is a bit lame i'm afraid, not too tricky just time consuming. and with a tendency to snowball.

i'll also apologise for some of the welding in advance. hopefully you cant see it too well in the photos :D but i'm just learning and finding 2mm steel a bit difficult with the arc welder. nothing structural though so its ok.

installation is a bit more difficult than with tdi's as with a tdi, you can just bite the bullet and buy an intercooler that fits in the space, and plumb it in through the space vacated by the old intercooler.

unfortunately this one's a bit more difficult as i'm running an isuzu 4jb1, which didn't come with an intercooler from the factory. the intercooler is an ebay special. i went looking for a saab 9000 one and found the one i have, a saab 9-3, which i got for i think £30 delivered, not bad for a brand new, never fitted intercooler still in its original saab box.

i had emailed the vendor, to find out how big it was, '40x30 cm' i was told. ok i thought, i'd like bigger, but at least i wont have to move the rad or anything. alas when it arrived it was huge, about the same surface area as the radiator, but with tanks on each end, making it a bit wider overall. i thought i'd give it a shot anyway though and see if it could be fitted.

alas summer holidays ended, so i ended up waiting about a year after fitting the isuzu engine beofre giving the intercooler a shot. holidays wil end again shortly, but hopefully it will not remain an engine bay ornament for a long time

here's it in place


and here's what it will be hooked up to


its quite big and sits where the radiator used to sit


radiator has been moved back 60mm, which seemed like an easy thing when i first decided to do it, but i had to cut up brackets, make some, new ones. had to switch the bonnet stick round too, but it sits abtit funny now as it was raining so i measured it rather hastily.

i also had to cut some holes for the tanks and for plumbing. again i thought it would be easy, but there's two skins on the inside of the wing and other reinforcement., so i tried to take out as little as possible


a run of grommet strip and the tanks poke through the wings.

bit of a **** picture, but you can see its a very tight fit.wings are crow barred up as high as they'll go with the existing holes and the cooler can just move back and forth when the clamps are not in place at the top bits of tesco bags are keeping the dirt out.


here's an in bay image, got to get pipes under the top hose and air intake and then into the cooler. probably have to move the power steering flask thing.

aat the bottom wher the rad is moved back, there is not much clearance between rad and power steering box. i have the hose in at th emoment, but its slightly squeezed and makes a bit of a hard turn out of the radiator. if it proves aproblem i'll get a 90 degree exit brazed on.


current plan for plumbing is literally plumbing materials. i can get my hands on copper pipe and various solder joints easily enough. it comes in good sizes, matching the diameter of the inlet manifol perectly and available in a size really close to the intercooler outlets. there's lots of solder on angles and downsizing bits as well so it shouldn't be to difficult to assmble. most importanlty its cheap. i'll need silicone hose to take the sharp turn out of the intercooler and i think i'll just use radiator hose to join the other end and also make joints for disassembly and to give the assembly a bit of flexibility. i can get rad hose from my dad's work for not too much (not 90 degree bends alas :( ).

so there it is, rather dull and simple tech. wouldn't mind any opinions on the matter if anyone thinks i'm taking the wrong route.

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not dull or simple - looks good to me :)

easy way to break into the inlet tract it undo the two bolts that hold the butterfly housing, flip the housing 180 degrees and bolt it back on - then the pipes end up parallel and you can pipe easily from there, cheap piping comes from dead landies, breakers (I did my first setup using old bits of SAAB 900 and 9000 intercooler pipework £fekall :) ) when you take the butterfly housing off I usually remove the butterfly and spindle completely, tap the bronze bushes and blank the bushes with a couple of bolts

hope that helps ?


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Nice install - I've got this ahead of me after I fit my new turbo. Overall that's a tidy bit of fabbing so far!

I hadn't appreciated how short the Isuzu lump is - the handling must be pretty good with the weight that far back too.

yeah with a short lt77 it sits behind the front axle. i've got a mid engined 110 :P

regarding the fans...

good question.

i got it from the scrappies. i went in and said i was looking for one and the scrap man said there's one lying out over in the corner of the yard. so i went to look at it, but thought hmm, i'll see what else there is. so after searching around under the bonnets of about 20 cars, looking at different push and pull fans and discussing it with my frined who had just completed a part of his course on turbines i took the one i had been told about in the first place.

so... i dont konw for sure what tis from, i think its from a sierrs, and is definately a ford part. i' m not sure what type of sierra it was though. if you look at ebay you may see some. its a rally good fit, perfect match for the radiator vertically and about 3cm too narrow to completely cover it on the horizontal.

jez, do you speak of the exhaust butterfly and housing? i removed the plate a short hile ago, but left the spindle as it seemed a bit of a pain in the arse to get out, lots of short strokes with a pad saw. i'd prefer it out as i'm aware diesels appreciate free exhaust passages, but it was a bit much work and i didn't want to remove the turbo assembly, its a bit crusty.

uni work beckons at the moment, but i'll maybe have a fiddle when some pipe and hose arrives and see if i can understand what you mean a bit better.

thankfully there's a plethora of info about on VE type pump adjustment.

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Super job there!

Ive the same engine in my 90 and have an all Al intercooler from a volvo. Its the full width, about 1/2 the height of the NAD rad but just as thick hoping to get it fitted in the next week or so.

Looking forward to seeing it finished Callum.

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  • 1 year later...

vapour builders at least have a whole car to not get on with, i only had a few jubilee clips, yet its still not done.

seeing as some folk were talking 'suzu i thought i'd update a bit more and maybe get moving.

mostly i was busy with uni, but now i don't have that excuse. i also had to gather lots of stuff, but i think i have it all now so can get going.

so firstly here's some pics of the plumbing bits i have accrued. some shiny stuff from viper performanace and then some not so shiny stuff from the scrap yard. it cost me about a tenner in total for the scrapy stuff (which included a lot of other random things and bits for other folk) so that was not bad value. the coppery shiny stuff is for filling in the blanks. i got it a while back as it was cheap. thre's proabbly a reason that its not normally used for intercooling, but its what i have and ally bends and silicone are too expensive for trial and error stuff. the copper stuff is also a good size match for both the isuzu engine and saab cooler. mayeb when i ahve it sorted out i'll change to alloy and proper bends.





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now some plumbing issues.

mostly these are of my own doing by putting in too big an intercooler and having lots of things hanging round the edge of the engine bay, however some of them are because of the engine.

it didn't come from the factory with an intercooler, so a bit of fiddlign is required.

pic 1 shows that there's not much space between turbo and manifold to get the plumbing out of.

pic 2 shows the bit that i think jez rotated so that he could pass the pipes. this is quite a good way to do it, but in my case it starts sending the pipework to the back of the engine bay and i would also lose that nice little bit to bolt the plastic intake tube from the air filter on.

pic 3 i therefore propose to clock the turbo by undoing the little bolts you see there and rotating it by one bolt so that the turbo outlet points away from the block rather than towards it. that should give me the clearance i require. i'm not 100% sure that lots of little parts wont fall out if i do this. perhaps i need to research a bit more. this is the best way i can see to rotate the turbo, everything else is hooked up to oil feeds and the water cooling system.




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another hold up was getting readings for stuff when tuning.

i got a nice racetech boost gauge. its from their pro range and is really clear and nicely made. unfortunately i couldn't find an egt gauge at a decent price (like under £200) until recently when i cam across the mcnally electronics combined boost and egt gauge. it means the racetech one is now up for sale, but it gives me a boost gauge and egt gauge and they fit in the one hole in the dash, which is handy.

so here's some pics. raceface120 fitted one recently, so you can see a fitted one in his disco thread, mine is still in its box at the mo, i still need an npt tap for the 2 probes.

in the box comes the gauge, thermocouple for egt, electronic sensor for boost pressure and lots of wires to hook it up with. unfortunately it didn't come with any kind of guide as to what wires went where. i emailed dave at mcnally electronics and he sent me the installation sheet striaght away. he also sent me a photo of a gauge wired up so i knew which colours went where. i was really impressed by their customer service, so here's there address http://www.mcnallyelectronics.com/ plug plug . including shipping, gauge and asociated bits to make it work cost £91, which i think is pretty good value. my only complaint is that it lights up blue and the rest of my gauges are bog standard green.

whilst talking gauges, donald (fatboy) was asking about gauges on his isuzu powered 2a buildup, so i've attached a pic of the standard rev from the trooper painted black and mounted up. its a good size and in this instance came free with the donor vehicle. given the peculiarities of the isuzu rev counter signal (from the fuel pump and operates on the earth :blink: ) its probably the easiest solution. i daresay you could flush mount it with a gauge panel if you so desired.






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jez, do you speak of the exhaust butterfly and housing? i removed the plate a short hile ago, but left the spindle as it seemed a bit of a pain in the arse to get out, lots of short strokes with a pad saw. i'd prefer it out as i'm aware diesels appreciate free exhaust passages, but it was a bit much work and i didn't want to remove the turbo assembly, its a bit crusty

I removed this whole assembly tonight and thought I'd post this for info. (I did it without removing the turbo but the engine is on the bench without exhaust).

The vacuum actuator is held on with three 12mm bolts. The oil pipe to the turbo has to be removed to get to the last one. The butterfly in the exhaust is held onto the spindle with two 10mm bolts.

The spindle is a pain... It looks like it must be fed through from the blank side, then the blank side welded up as it does not pull straight through. I had to chop the middle out of the spindle so that both sides could be pulled in.

Now, the casting at this area is 50mm ID. The spindle is "half moon" and without the butterfly on, its still 17mm wide or if it is side on, 9mm. So, the best case, if the spindle is still in, it takes up 43% of the area, if the spindle is narrow side on, it takes 23%.

So, I guess its worth removing! ;) Mind you, I'm not awfully sure I'm convinced how it works - I guess that with the engine running at high revs, the vacuum pulls the butterfly closed (partially), preventing fumes leaving, thus having a second shot at the unburnt fuel? :blink:

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I removed this whole assembly tonight and thought I'd post this for info. (I did it without removing the turbo but the engine is on the bench without exhaust).

The vacuum actuator is held on with three 12mm bolts. The oil pipe to the turbo has to be removed to get to the last one. The butterfly in the exhaust is held onto the spindle with two 10mm bolts.

The spindle is a pain... It looks like it must be fed through from the blank side, then the blank side welded up as it does not pull straight through. I had to chop the middle out of the spindle so that both sides could be pulled in.

Now, the casting at this area is 50mm ID. The spindle is "half moon" and without the butterfly on, its still 17mm wide or if it is side on, 9mm. So, the best case, if the spindle is still in, it takes up 43% of the area, if the spindle is narrow side on, it takes 23%.

So, I guess its worth removing! ;) Mind you, I'm not awfully sure I'm convinced how it works - I guess that with the engine running at high revs, the vacuum pulls the butterfly closed (partially), preventing fumes leaving, thus having a second shot at the unburnt fuel? :blink:

the one in the exhaust is an exhaust brake, cable operated by hooking it up to the brake pedal. they are called jake brakes in other places. some people fit them aftermarket, but the seize up often on isuzu's so are worth removing. the one in the inlet manifold is part of the quick warmup system, which is vacuum operated and restricts air into theengine to warm it up quickly. these also have a habit of failure. i think at some stage i shall remove both spindles. both flaps are off now, but its mabe worth ditching the spindles too.

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My exhaust flapper only had a vacuum actuator on it :huh:

On the inlet one, I've just removed the sandwich plate with the actuator and flapper / spindle. It moves the inlet elbow a bit closer but it fits fine. However, the inlet manifold seems to be a bit oily so I'm going to whip that off and give it a good clean out..

While I was pottering about on the exhaust side, I decided to paint the heat shields with a temp resistant red paint I had kicking about. However, its ended up a luminous PINK !!! WTF ?? <_< I'd post a picture but didn't have the camera handy tonight. ... honest.

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  • 2 months later...

i finally made some time to finish this off, so now i can post some pics.

there has been a bit of isuzu talk on the forum recently, so perhaps this can help some folk with their own projects.

frist step to make sure there was no going back was to rotate the turbo the alloy bit with the inlet and outlet can be unbolted and clocked so it gives you a bit more clearance to get intercooler pipes out. on engines intercooled from the factory, i think the position i have my outlet in now is standard. some of the bolts for this are really fiddly to get out and even more fiddly to get back in, so make sure you have ratchet spanners and maybe some fags and cups of tea.

so pic 1, is the bolts you need to tackle, and the others are pics with the housing off. i'm afraid i don't have a picture of it back on without any hoses attached, but you can kind of see that it now fires away from the engine rather than towards.





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so, next bit, plumbing it all up. this took a long time as i did a fair bit of rearranging of the engine bay, taking the opportunity to rectify some parts of that i was not happy with after i initially changed engines. no pics in progress i'm afraid, but its kind of specific to the vehicle. i was making a saab 9-3 intercooler connect up to an isuzu engine in a land rover so there was lots of awkwardness.

1st step was to enlarge the holes i had cut in the wings a while back when i put the intercooler in place, they were too tight and didn't let me get the 90 degree bends out of the intercooler on sufficiently. so i could actually get the air filter out, i cut 35mm off the legs of the air filter box (and cleaned it up a bit too and filled a hole as arcs and thin stell don't mix too well). this also allowed some of the intercooler hoses to get back round from inside the wing.

power steering reservoir moved to the other side of the eingine bay, above the power steering box and was mounted on a new bracket. the convoluted hose run in the past meant it needed pressure to bleed the system, hence the schraeder valve on the cap. in this position it bleeds fine. of course i had to extend the return hose to move it and 15mm hose that likes oil was quite difficult to find. the hose i used was 16mm so jubilees had to be very tight to stop leaks.

my (quite large) box of electronics to run glow plug timers and the associated relays was relocated underneath the blanked air intake on the drivers side wing. it is on a nice little backing plate designed to be an easy fit, but stuff poking in the way makes it a sod to get in and out and i hope never to have to remove it again. in its place i decided to put a land rover header tank in place of the isuzu one i had been using. with the previous setting i had used a 1/2" bsp pressure relief valve as my radiator cap and the isusu bottle as the reservoir, but was not happy withthe setup. the new reservoir is from a range rover or disco, i think defender ones are different as this one needed spaced down to stop the cap hitting the bonnet. i uses a 35-15-35 coper solder tee piece to connect it to the bottom hose, i already had a connector in here as the standard bottom hose is too short for the isuzu engine, so it was a nice solution. at the engine end it attaches to a wiggle bit of pipe that can be clouted by the axle when the front of the car takes air. thankfully this bit of pipe can be unbolted, so i'm going to get it shortenend at some stage so that the 2 can't meet again...and split my bottom hose...again.

other wee things were moving the box which contains the electric an relays (thermoswitch which goes into the thermostat housing is from a hi-jet for those of you looking to run leccy fans with a 4jb1 and then plumbing. my plumbing is a really mixed bag of bought elbows, discovery intercooler plumbing, volvo 940 turbo intercooler plumbign and some domestic (well commercial size probably) plumbing, 42mm and 54 mm o/d pipe, which was a better match than any proper pipe i could find even if it does look a bit ghetto. took a while to get the hose runs to sit nicely and without strain and i had to keep buying more expensive silicone hose, but its now ok. i expect most intercooler installations will differ from each other, but this may give you some ideas of the angles you need and routes for pipe runs. Brackets are flat bar bent round with a kick up at the end so they can be tightened and grip the pipes. they wre meant to be dead clever and threaded too, but i buggered it up.

photos in not too much of an order, but might give you some help. photos 3 and 4 feature deisel jim's beautiful genuine parts radiator brackets that i bought from him, then promptly cut in half to extend. they work very well though jamie, much better than the standard ones which attach to the wings.







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and so on to actually making use of the intercooler.

i vacuumed out the assemble before running, so it was fee from any swarf that might have fallen in whilst i was drilling things etc and this all sooked in, so it was airtight at least. first run just with the intercooler plumbed up revealed i had a problem holding the hoses on, the end of the elbow straight out of the turbo, without a lip on it kept blowing off, no matter how much i tightened the jubilee clip. i had to, therefore thoroughly degrease both pipe and hose, then use a high torque jubilee to stop it from blowing off. strangely all similar joints are fine, not sure why that is.

once i had sorted this out, though i discovered the car had an annoying let-off valve that didn't like the boost to go beyond 0.7 bar. i think this can be removed and discarded, i just increased the preload on the spring inside with some washers and now it can happily go over 1 bar.

handily the 4jb1 uses a bosch VE 'type' fuel pump, so there are instructions handily available on this here site in the tech archive for tuning, but there are some differences.

1st step is the smoke screw...there isn't one on a 4jb1 :( at least not in the same place as on a tdi, so i had to skip this step.

next step i ignored all the instructions and opened up the cover where the smoke screw should have been and the diaphragm fell out. i then went back to the instructions and found this was not such a good thing as its position was critical, so the proper way to do things...

when removing the top, mark with tippex or sumint the position of the diaphragm before removing it (although it may just come out with the lid like it did on mine). now you can take it out and have a look. on the end of it you'll see the eccentric conical shape. the diaphragm moves up and down withthe intake manifold pressure and a wee rod that comes out of the fuel pump is guided in and out by the cone shape. if you look closely (as seen in one of the pics) the rod wears a little groove in the cone, so if you didn't mark the diaphragm, this should point towards the front of the car. this will also show you that if you had been reading the tdi tuning instructions and been usin the '0' mark on the diaphragm itself as the position marker, like the tick mark on a tdi, that the '0' means nothing. you'll also note the ecentric shape of the cone and it is this which is used adjust the movement of the rod. the closer the rod can move to the centre of the shaft at the top of the cone, the more fuel is introduced. i initially whacked this round 270 degrees clockwise. as a result, the car went hella fast, but was hella smoky and exhaust gas temperature could be made to rise VERY quickly. i had read that 700 degrees celcius was the top safe temperature and i got to that quite quickly when i put my foot down. i backed it of to 180 degrees clockwise, but it was still smokey, so i have backed it off again to about 120 degrees clockwise.

you should make all your alterations one at a time and write them down too, i didn't, which was pretty stupid, so i've had to backtrack a bit when fiddling with the fuelling.

next step is the star wheel, which you'll see when you remove the diaphragm. a plastic toothed wheel which sits under the spring this can bepushed round with a small screwdriver or just using your fingernail, you don't have to remove the spring when you do it, but it just sits in that position, so it might get in your way. going by the land rover tdi guide i wound this round to 180 degrees clockwise, but i did it at the same time as fiddling the diaphragm, so i don't really know what effect it had. i'll have to fiddle with this further to find the optimal setting. doing the alterations one at a time is a much better idea.

final thing, which makes a big difference is the fuelling screw which is on the back of the pump under a metal cover. its difficult to see from the top, but its the protrusion below the green rubber cap (note, its you don't touch th green rubber cap, its a seperate metal cover below that). removing the metal cover for the screw is a pain in the ass as its quite soft and just bends. persevere and it will come off though. once you get it off, you will be pleased t note that in japan they dont bother with tack welded metal lock rings to stop you fiddling so none of the grinding with a dremel necessary with land rover tdi engines. all there is is a slot scre, secured with a locknut, so all you need to do is loosen the lock nut and you can scres in the fuelling screw. for this i went for 2 whole turns clockwise. this made by far the biggest difference. its possibly a bit smokey, but i'll see how i get on with it.

so, pictures...

1 - annoying let off valve on the intake manifold

2 - cover on top of the pump where i didn't find a smoke screw :(

3 - cover off and the diaphragm

4 - eccentric cone on the diaphragm

5 - better picture of the cone, which shows the groove worn by the rod and where the default position should be if you want to reset things

6 - underneath the diaphragm, the star wheel, with the spring still in place. you'll see here my tipex marks and that i have rotated it through 180 degrees, clockwise

7 - fuelling screw on the back of the pump, which i rotated 2 full turns clockwise.

8 - idle screw. winding in the scre on the back of the fuel pump will make your idle go quite high, so you'll need to adjust it back down. my throttle cable was rather short, which made things difficult, but when i finally got it slack enough, i found that it was no longer the idle adjust screw or the cable restricting it, but something else, so i'll need to investigate this further. my current idle speed is 1000rpm. it should be 750-800 rpm.








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so, conclusions, sort of.

well my fiddling has kind of stopped at the moment as when firing up the engine for a test run i discovered that one of my manifold studs had snapped. spent a lot of sunday trying to get it out, but it is in an annoying place. it did show me the source of the annoying noise that my engine was making, so that's one good thing., but the manifold will have to come off now and will need a new gasket, £26 from milners :( . car needs to be used to launch a boat tomorrow night, so i'll not be able to strip things down until later on in the week.

so to conclude for now until i fix the manifold, performance gains have been pretty good, was quite comedy fast when i had the fueling maxed, but now its a bit more sensible. i can now accelarate quite well up hills and be changing up when i do so rather than having to hold a gear at higher revs. i'm also finding the gearing a bit short, the venerable lt77 isn't the quickest shifter on god's earth so i run out of gears quite easily. i have a 1.2:1 transfer box in the garage and that should help things. i'm running 33" tyres at the moment, but if i upgrade to 35's in the future i may have to go back to 1.4, shall see.

had hoped for a bit more gain at bottom end, jsut for taking off etc, but maybe i'm too used to modern common rail diesels. smoke is still a bit noticeable for my liking, so i'll keep fiddling. i think i'll also try upping the boost a bit and see what that does for things. the TDi guide suggested there would eba drop off, but pressure just at the intake manifold is 1.1 bar, so it is as normal, if not a little higher after fiddlign with the fuelling.

anyway, hope this might help some folk going down a similar path, i'll maybe post upa few more details when i've fiddled some more.

if anyone has anythign to add, comments, advice etc, please do so (especially if i have given bad advice in any of the above) also if anyone has recorded their own pump settings they've made on a 4jb1, that would be really useful too.



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nicely done Callum - if you want more puff on the boost then you need to play with the overboost blow off valve that sits between the fingers of the intake manifold, we used to fit a pneumatic ball valve to the end of it - so you could run stock boost or close the tap for high boost on demand, where are you taking the wastegate pressure line to?

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This will be very useful for me as I'm following a similar route, just a few steps behind you, thanks ;)

I've just been sidelined by holidays and traumas with other vehicles - I now need to get my 90 back on the road to provide backup while my other vehicle gets sorted.

  • Do you have an "Idiots Guide" for the microswitches and other electrics on the fuel pump?
  • Sounds daft but what do you do to turn the engine off? (I've only previously played with V8's)
  • I guess you used a fuel filter / lift pump from the donor?

I've shifted my radiator back a few inches to get the intercooler inlet/outlets into the gaps on the wings (I'll upload a photo later).

Thanks again, keep going :D

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The pump on the isuzu's isn't a bosch VE, it's a japanese copy of one and they have many detailed differances.

IMHO you've got far too long an inlet tract to ever make a differance to low end torque, in fact i'm suprised it isn't laggy as hell.

I run a 2.8 that i've fitted a 3.1 top mount intercooler, i've repiped the boost enrichment pipe to the turbo side of the intercooler, removed the fast warm up butterfly and spindle, i've fitted a 300tdi adjustable wastegate actuator, blanked the egr, fitted the larger diameter 3.1 turbo down pipe. I run a 1 bar of boost, i've increased the preload on the boost enrichment pin and is on it's steepest side, the full load fuel screw is in about 2.5 turns.

I have almost no lag, you can only see the exhaust smoking in the dark in the headlighs of following cars. it passed its last mot smoke test with an opasity of 2.5

This setup really flys, i can out accelerate my mates tweeked disco even when i've got 1 ton on the back!



This is that engine in it's new home.

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  • 1 year later...

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