Santa`s JABBA IHI powered LCR - 1 year on
Sorry guys - I am having trouble keeping up with this post - it’s this Christmas thing - call it PMT - pre mince pie trauma!!! - Now where was I?
I have indeed used Aquamist from the outset to good effect I think!!
Again, I can only indicate in honesty my particular experience with regards to my own car, namely, that I have not had any problems so far, with either Jabba manifold/IHI exhaust housing/or downpipe in nigh 34000 road miles, whilst running the turbo at a nominal 1.6 bar boost.
I
have had trouble, yes, with the turbo bearing cartridge - at 17000 miles the cartridge dropped and the turbo seized - I was able to drive the car 350 miles back to Jabba where they changed the cartridge and compressor - the turbo exhaust housing was OK - I am now at 17000 miles further on, with the new components without problems, still running the original 1.6 bar map
I explained previously, that I foolishly changed the DV for a faulty unit - I kick myself! - I should have realised something was wrong, because the damn thing was making sounds somewhat similar to those I heard in the underwater section of the `Whale episode` in Planet Earth - Avast! she blows Capin`!!! - I know! - I’ve had a difficult Year!!
It happened a week before GTI inters too! - the turbo was very new, and I was thus, `well inhibited` by the prospect of breaking something else, and incurring yet another £1000 bill ten days on from the last, so, to cap it all, my times down the strip were rubbish - did a 5.64 0/60 which in truth was just a smidgen quicker than the `Fastest Badger in the West` though Bill gave me a darn good trouncing over the quarter!
I had the pleasure of meeting Bill for the first time at GTI, and the good fortune to be able to show him the offending DV and solicit his opinion regarding its failure. and that, added to the views of other knowledgeable guys I met there, led me to the firm conclusion that the primary reason for the cartridge failure was the faulty DV.
I’ve reverted back to Jabba`s original setup, and to date 17000miles on have had no further probs - having said that knowing my luck, I’ll probably go out today and blow it up - I’ll keep you posted!
Regarding Bill’s previous posts - he is far more knowledgeable and experienced than I in all matters relating to the 1.8T and I would not for a minute dream of contesting his point, that the harder I push the turbo, the more I encroach upon its innate reserves - for I know he is entirely correct in saying that.
As I said previously this modding game is for me, by definition, a very personal experience - the idea, in my mind, being to produce a car which is very specific to one’s personal needs - that which suits me, will not be to another’s taste or requirements, not least because of differing conditions of personal use - and of course that’s fine! - That’s what it’s all about!
With regard to my project and my choices with the LCR - I had a need for a general `day to day` road car with a bit of `spice` - something different, to inject a bit of fun into the daily grind - the LCR, was for me an ideal candidate - in standard form it was a bit bland, and OK it
was FWD - but it looked good, and I felt good driving it - it was strong, reliable, and had headroom left in the hardware for some useful mods, without compromising too much the primal concept of the design.
What I was after was a very good road car! Now, my experience is, that, a very good road car may be many things - one thing for sure it is not, and that is a very good track car!
In my book the just two don’t mix - the two areas of operation are quite different and success and effective performance in either requires two completely different `mind sets with regards to construction and use.
OK - I know about track days and general fun things like that! - if I were to do them, I would go and buy a 2nd hand Suzuki Liahanna like in Top Gear and give that a proper thrashing - that’s a real test of anyone’s driving ability!
My personal use entails lots of motorway running and high mileages, so I need good mid range torque to make top gear use feasible in the 60/70/80 mph commuter shuffle, and also good economy and reliability, to keep a lid on the costs my 25000 mile per year hobby.
These constraints entailed the following particular engine choices for me:-
- stay with the small port and standard pistons, because most normal running is off boost, and, at lower rates of gas flow, smaller ports give higher gas velocities, and thus better atomisation, which when combined with effect the highish CR delivered by the standard pistons, offers the best chance for optimal fuel economy in normal road use.
The standard pistons too, are also strong enough to accommodate the proposed increase in performance - the only other task was to conservatively port the head, in order to maximise its potential.
- With regards to turbo choice, I wanted to stay as small as possible in order to minimise the prospect of excessive turbo lag, which is for me, is, at best, a right pain in the arse, and at worst, in a fwd road car, just down right dangerous! -
My efforts with the chipped KO4 were just OK in terms of turbo lag and bottom end response - but the top end was a little lacklustre - hence the IHI, which I think is a wee jewel of a turbo - rather like a KO4 on steroids with excellent top end whilst having roughly the same spool as the standard offering.
I personally asked the lads at Jabba to push it to 1.6 bar because I wanted the maximum possible midrange torque to mask and minimise the perceived `lag effect`
Of course I realised there was a risk in running close to its limits but I rationalised the risk in the following way for my particular use.
If you consider the turbo system, its potential to misbehave, and the consequent effect of that misdemeanour on the rest of the immediate engine components, then you have two main areas of concern - those areas which tend to more likely to be subject to thermal stress - worries in our particular case:-valves/ manifold/exhaust turbine housing/down pipe, and those areas which are more likely to suffer mechanical stress -in our case again: - conrods and turbine bearings
Of course, in both cases, thermal and mechanical, the mainstay of defence against mishap, is the control system and its effective mapping, however, with my desire to run so close to the limits, bearing in mind the heat related issues, I decided to change the standard intercoolers and use Jabba`s front mount, together with the basic Aquamist system running 80/20 methanol mix as a final backstop to keep inlet temps under control.
I changed the valves to better quality items to minimise any potential weakness there, and finally, with the main `Achilles heal` of the setup being the exhaust housing, I made sure that the exhaust system was as free flowing as possible - 100 cell cat/ no centre box/ 3" as far back as possible/ 2.75 over axle to a single back box - so as to eliminate any possibility of backpressure related overheating issues with the manifold and housing as a consequence of restrictive exhaust flow.
Finally, to keep an eye on things I decided to use the very excellent Spa design dual boost/EGT gauge - the exhaust temp sensor had to be installed post turbine, which may be the best place for safety considerations regarding the turbine blades, should the probe fail - however it’s obviously not the best place for accurately determining the temp of the housing. It does, however, with experience of use, and intelligent observation give adequate feedback regarding the state of play `down there`
On the subject of mechanical stresses relating to issues of boost pressure, it’s worth saying that the effective charge densities you get on the mapping dyno with a new turbo on a hot July afternoon are likely to be quite different to those you will get later on with 5000 miles under your belt down the road of a cold January morning, so beware of the thinking that `all will be well `cause I’m only using 1.4 bar! `
With that in mind I decided to upgrade the rods as a safeguard against an`overexuberant` compressor and associated boost spikes, and I also used Jabba`s dinky little boost controller - a fabulously simple and effective gadget, which allows me to `tune` the car on the fly, in real time as my mood takes me - I can roll it back to take account of conditions and circumstances and give the turbo an easy time, or spin it up for moments of madness[fun] - all in the fraction of a second!
So how does this lot translate into the practicalities of everyday use?- well its fandabidosie[ a wee Scottish term] - I just love the car, its all that I ever wanted to be - never boring, always challenging to drive - so its a big thumbs up to the lads at Jabba!
With regard to the specific worries regarding the thermal and mechanical stresses on the turbo, well I’ve tried to explain my approach ,and I think I have been successful so far in coping with the potential problems.
To put things in perspective - the highest EGT reading I’ve seen [870deg C downstream of turbo] was observed after a sustained attempt to maintain speeds in excess of 165mph gps - I’ve also seen high readings using full performance in the lower 4 gears over a distance of a number of miles!
Most `normal` encounters however are quickly dispatched and mostly brief, because the car is so rapid - EGT is normally never a
problem
My car is a road car as I said, and I hope you’ll agree that the chances of using the full performance on British roads to an extent where EGT is a
problem notwithstanding considerations of legality and Public safety are rare to say the least!!.
The car will pull a load of mid range boost if I let it - and I have to admit to being a bit of a `torque junkie`, it’s so addictive - so on the mechanical side, I may well be vulnerable to bearing failure, we’ll just have to see! - Luckily I have boost gauge to monitor pressures, and the boost control to limit my excesses, and - so far so good!
I am always somewhat bemused by questions of vehicle reliability - I mean, how long is a piece of string! - One man’s trusty beloved, is another’s faithless harlot ! Undoubtedly, there is one thing that is more sure than death and taxes, and that is the fact, that your car will go wrong sooner than you think! - especially if you stick a big turbo on it!
I forgot to mention my final weapon defence in the battle against meltdown, and mechanical Armageddon - when I see things getting too hot and heavy, my brain sends a wee message to my right foot which says - `please reduce pressure on accelerator pedal!` - works a treat in lowering temps and pressure - in the old days they called it `mechanical sympathy` - don’t think there’s a term in the lexicon to describe it, these days!
Well guys I’ve come to the end of this weighty `parable of a petrol head` - I hope it’s given some insight and inspiration. I’ve also come to the end of my journey with the yellow car - it’s been great fun, cost a lot of dosh [purchase price of vehicle + total cost of all mods since new now sniffing at £40k all in!!!] - But now its time for me to move on to a new project.
Can’t leave this `novel` though, without also saying what a great pleasure it has been meet some of you, this last year, and to put some faces to those strange avatars lurking on the site!!
Last but not least, I must offer huge applause to the lads at SCN for a job well done, in providing for us , such a fantastic forum - and it’s free too!!
Cheers!
