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MG MGF Technical - VVC Inlet On MPi

Hi Guys,

I have just managed to get my mits on a VVC inlet manifold. I currently have a 97mpi with a 52mm Throttle body fitted to it. A vader kit is connected to this.

I am currently saving for a stage 2 head in the not so distant future. Although i've been told Ive got to get the wedding using wedding cars tonbridge out the way next year first!

I know that to get the real full benefit from this i should really have a modified head already but I've gotta save!! lol

I am eager to get started on the installation of this new piece of gear. Looking at the differences between the VVC version and MPI version I see that is has a MAP sensor stuck to the side of the upper chamber.

My MPI's MAP sensor is built into the ecu with a vacumn hose connecting to the current manifold.

My question is what do I do!! How do I connect it all up? Where do if plug my ecu vacumn hose on the vvc manifold???

With out this being connected I would imagine this is a no go. Am I missing something obvious???

Any help most gratefully received!
Chris Glen

Chris the most obvious thing you have missed is that this inlet is designed to fit a VVC head which has substantially larger inlet tracts than the MPi head, simply bolting this on will cause a massive mis-match of port profiles with a loss of torque and power, it will also act as a heat sink for the head and heat the incoming air making even less power.Stick with the stock item it will work better.
mike

I could not have said that better Mike.

I saw Roger Parker's solution to this particular problem a few years back - he'd had the MPi head ported to match the inlet manifold ports, and additional metal let in to enable a good seal between the VVC manifold, gasket and cylinder head.

That said, others have installed VVC plenums onto MPi heads - Andy (Scarlet Fever) Phillips for one. It is entirely possible.

Mike, how do the alloy manifolds fitted to TF135 differ from the original VVC inlet plenum? Their upper surface appears identical - is the section mating to the cylinder head a different casting to the VVC item?
Rob Bell

Okay it looks like i should hang off then until i get a new head then. I was going to go for a MS Stage 2 Head.

But then i thought a tf135 head complete with the cams and then ported?? What would i have to do to go along with this?

Chris Glen

Following on from Rob's input the head had the extra metal welding in to allow for a clean port match. That head is still working well on a R 218iS having covered 80k miles. Without mods note what Mike says.

The Euro III spec engines with MEMS 3 have a different arrangement for the map sensor, compared to VVC with MEMS 2J. When fitting to the earlier MEMS 1.9 system it just needs to be given a vac connection to the plenum. If there is only one port then the simplest solution will be to tee into the vac connection between the plenum and the fuel pressure regulator.

TF 135 is essentially a standard MPi head with a pair of VVC exhaust cams. My very heavy head modification programme of a deliberate mix of MPi and VVC elements was intended to provide the maximum useful power band whilst avoiding any need to look at mapping. This meant that the head had VVC inlets heavy work on the inlet ports, inc the welding, but just heavily detailed MPi exhausts. Standard cams were a very specific choice to maximise the engine operation with standard mapping.

Measured 33% increase at the wheels on comparable before and after power suns was a satisfying result and complete smoothness and economy (when not using the extra performance). The mapping felt at the limit though. I have worked with ITG in developing air filter systems that work and so not only am I biased to them but use them. The main point with this aspect is to use a high flow ENCLOSED assembly to keep control of intake air temps, open filters make noise but are exposed to widly fluctuating temps, and thus lose power and torque.

In the 200 this set up has benefitted from a very effective Janspeed 4-2-1 manifold and system and a 52mm throttle and whilst not run on the rollers is quite clearly sharper than when in the MGF. Estimate is around another 8 to 10bhp, and the 200 MEMS 1.9 has coped better than the same series unit in the MGF.

More recently I have gone down the road of a VVC head lightly reworked with a matched VVC inlet. Piper 270 cam solid cam conversion (Mikes parts very good here) and as this is in a FWD chassis a decent 4-2-1 Janspeed manifold and system. MGF can only fit a 4-1 based system and loses half the benefits of a manifold that has decent secondary pipe length. 52mm throttle and ITG Maxogen. With the standard MEMS 1.9 it ran like a lame Kangaroo.

Such mods needed a different ECU and I have an awful lot of time for Emerald. With one fitted, and this is a 'plug compatible' simply fitted unit, the engine made 170bhp on the Emerald rolling road (Emerald's flywheel interpretation) More recently still the engine has been fitted with multiple throttle bodies and with some alteration of the mapping the performance is another significant step better. There is some more smoothness and possibly some more power from Dave Walker's finite touch at Emerald. Experience with similar specs suggests 185 ish bhp and with full low rpm driveability.

Any higher than 185 and this would be a real bonus, as with the cam and head work done so far aimed deliberatley to maintain lower rpm driveability as we use steel bodied cars that are much heavier than Caterham and Lotus Elise models that can live with higher peak power but poorer low speed torque. In addition I aim to ensure that the car can be driven just as the standard one is in any form of traffic.

Parallel work on a VVC that we (my son and I)has been fitted in a very early 400 5 door hatch to full EURO III (MEMS3) spec illustrates how much easier and less costly it is to reach a 170bhp goal with a single 52mm throttle body. Incidentally usung a modified early 56mm Rover throttle from T series didn't give any advantage over 52mm.

IU have had a chance to use an Emerald on a VVC and surprisingly there is a useful gain in the low to mid range rpms by reducing the duration in just that area. There is no gains over standard MEMS 2J or 3 in maximum power on the near standard engines. I am yet to try throttle modies on a VVC but am waiting for specific equipment to come available and then all will be set to find out if very simple bolt on parts can get towards 190 fully tractible bhp in a VVC whilst still running VVC.

Rog
Roger Parker

>> But then i thought a tf135 head complete with the cams and then ported?? What would i have to do to go along with this? <<

This is exactly the route I've taken Chris - a TF135 head which recieved a "Quick and Dirty" port from Dave Andrews (a surprisingly comprehensive bit of work for the misleading name IMO) - bolted to my '96 block, and using the standard MEMS1.9.

In brief, what you need to do is tap in a distributor spindle into the end of the inlet cam, bolt on the dizzy. The other modification I had Dave do was to tap the cylinder head to take a manual tensioner (preferable, in Dave's opinion, to the auto tensioner on engines that are used enthusiastically).

Apart from those relatively simple 'problems', the T135 head is practically plug and play. :o)

I also have a 4-2-1 exhaust manifold and enclosed airfilter (Rover 820!) - which is essential for power on an F, where ambient temperatures in the engine bay can soar over 60 degrees Celcius....
Rob Bell

"That said, others have installed VVC plenums onto MPi heads - Andy (Scarlet Fever) Phillips for one. It is entirely possible."
The VVC inlet fitted to Andy's car was done at the same time as we fitted a ported head so matching was done at this time.The second head Andy fitted I ported and was aware of the configuration so again it was modified for the VVC inlet.

Mike, how do the alloy manifolds fitted to TF135 differ from the original VVC inlet plenum? Their upper surface appears identical - is the section mating to the cylinder head a different casting to the VVC item? "
I have a 05 135 Tf in at the moment for head work so will let you know when I strip it as to what the set up is. The stock VVC inlet ports are around 37mm dia and the MPi head is around 34mm dia, it is Ok to have the head ports slightly larger than the manifold but not smaller. There is another consideration with head ports.. when cast the ports can be offset from the true position , this varies from head to head and templates have to be used to correct any offsets/misalignment. So bolting on a VVC inlet without any mods ( as Roger has outlined above)or thought to the above will result in less 'power'.
As Roger has pointed out dumping the VVC cams and fitting solid cams ,ECU and a lot of 's and time will result in similar power to a lightly tweaked stock VVC producing 170's and be more frugel on the octane juice.
To summarise (IMO) if you have a MPI and a limited budget stick with it and fit larger inlet valves and a half decent port job,exhaust manifold/induction will give good results 'similar'(Dave Walker dynoed at 157.5 with 2x VVC exhaust cams) to a 160 but with more bottom end torque.(You can fit VVC exhaust cams as I have done on my car, I threaded the rotor stub so it would fit the end of the cam:-))This gives a usefull gain over stock cams and doesn't require the adjustable verniers, ie just bolt on no RR or dial gauges strictly neccessary.
If you have a VVC and looking to hit around 170 then attention to detail with the head/valves and again inlet and exhaust bolt ons will give 170ish.
My advice if you are seeking to hit 180 and above then it is possible but cost it out first and see if the money is not better spent on improving driving skills (and/or brakes and suspension) first as this will allow you to perform better and reach the limits of the car first before moving on with the tuning. With the resouces I have I still find the MGF/TF is most enjoyable (as a daily driver taking fuel economy, around 40mpg, and reliability as parameters) at power limits below the 180BHP mark which what the engine was designed for.
mike

This is all great help guys! Thanks for this.

Good Idea about the T on the fuel regulator pipe roger. I was hoping that would be the answer. On my mpi they are both next two each other.

Im not looking for full on super power. Just enough to make my little car a little bit more frighting! After fitting big discs. Bilstien shocks. Poly bushs lowering knuckles etc etc etc I want now to have that extra umph!

The one thing I dont want is to frighten my gran my extreme reving and having to push the car with extreme mods.

I think i will look around for a second hand tf135 head and then contact mr andrews for some dirty work! LOL. Can you do this as well mike?

How much time/effort/money!!! did all of this cost you rob??

Now that I have the VVC inlet i might as well keep it and have it match with the new head i think. Even if it doesnt really add to much to the engine it will look nicer than my plastic one!

Is this the correct route do you feel? I really want to make sure before i spend a wad!!!






Chris Glen

"Can you do this as well mike?" 8-O See answer below.

http://www.mikesatur.co.uk/fx05.html
http://www.mgcars.org.uk/satur/pdf/tuning2005.pdf

"Now that I have the VVC inlet i might as well keep it and have it match with the new head i think. Even if it doesnt really add to much to the engine it will look nicer than my plastic one!

Is this the correct route do you feel? I really want to make sure before i spend a wad!!!"

The VVC manifold will give more top end power gains at the expense of lower end torque..you decide.

mike

>> How much time/effort/money!!! did all of this cost you rob?? <<

The TF135 head, complete with cams etc, was 100 quid. The DVA porting cost another 400 notes (including the tapping of the head for the manual cam belt tensioner). Reassembly was part of a head gasket repair - so no exact cost for that...

I don't know how much power I am getting yet until we have the opportunity to return to Dave Walker's RR for a check on performance. :o)

>> I have a 05 135 Tf in at the moment for head work so will let you know when I strip it as to what the set up is. The stock VVC inlet ports are around 37mm dia and the MPi head is around 34mm dia, it is Ok to have the head ports slightly larger than the manifold but not smaller. <<

That will be very interesting to hear about Mike - look forward to the update. Curiously the EPC doesn't appear to list the inlet manifold for the TF135 (unless I am missing something?)
Rob Bell

Where did u manage to get your head from rob??
Chris Glen

my thoughts exactly...
mike

Rob did you check the inlet port sizes before fitting it?
Mike

Had the head off today and was a bit surprised at the findings 8-{]
The ports are totally mis matched. The inlet is a stock VVC, same part number. Have some picture available and will post them later.
mike

I have a TF135 manifold and a VVC145 manifold in my personal MGF stock, you never know when you'll need one ;)

The lower manifold is identical only the intake air temperature (IAT) sensor is blanked off for the TF135 since it uses the MAPT sensor. Biggest problem when fitting the TF135 manifold to MEMS1.9 engines is where to fit the IAT sensor ? The VVC uses a plastic heat insulating bush. Without this bush the sensor which uses copper(?) thread will be warmed-up by the metal of the inlet manifold resulting in wrong readings so simply drilling and tapping some tread into the TF135 manifold isn't an option I think.
Interstingly even the partnumber on the lower manifold hasn't changed: LKB107010 SG. However the TF135 item has the letter "T" carved into the moulding whilst the VVC item has "NIPO" (or something like that) carved into it. Both by hand. The TF135 manifold also has very small D04 "hit" into it with type-writer-like letters between cilinder 2 and 4 on the bottom of the flange which fits to the cilinderhead.

The upper manifold (plenum chamber) has had more changes to it:
- VVC tekst has gone
- piece with the VVC's MAP sensor cut off (wasn't this to fit in the engine bay of the Elise ?)
- Added hole for MAPT sensor
- moved metal cap (under old MAP sensor) to the right
- added vacuum stub next to FPR vacuum stub (new one blanked of for TF135 engines)
- small redesign to the flange of the IACV

The VVC manifold has been extensively reworked after the moulding process. All areas the different parts of the mould didn't match 100% are still very much visible on the TF135's upper manifold.

Interestingly the partnumber for the upper manifold has in fact changed ! On the VVC it's SG LKB107040, on the TF135 it's SG1 LKB109541 The VVC item has "R167" (?) carved into the moulding. The TF135 has no additional tekst on it.

It could be possible the VVC lower manifold didn't receive the hole for the IAT sensor's bush in the moulding process but this was allways drilled in afterwards. This would explain why the partnumber hasn't changed.

How's that for allot of useless, yet relevant information ;)
Sander

Mike - I am astonished! I can't quite believe that Rover would deliberately mismatch the plenum to the head like that... amazing for all the wrong reasons.

Sander, brilliant information there, thanks! :o)
Rob Bell

http://tinypic.com/ofzrc4.jpg
http://tinypic.com/ofzp6u.jpg
These are the two pictures I have taken, the first shows a gasket on the inlet manifold and the next picture shows the same gasket on the inlet manifold.

Sander.."How's that for allot of useless, yet relevant information ;)" Information is never useless.. only if interpretated incorrectly;-)
mike

That should read the first picture is a cylinder head.
mike

That looks like a 2-3mm lip on the head there Mike. Oh dear.

One question though - is that a used 135 head? If so, why is the step inside the manifold gasket so clean?
Rob Bell

>>> How's that for allot of useless, yet relevant information ;) <<<
We just adore this kind of information ;o)

Just for the archive:
PTP RT Sport 165 kit comes with the lower manifold being LKB107010 SG
Erik

Rob Bell, North London
That looks like a 2-3mm lip on the head there Mike. Oh dear. (The stock VVC inlet ports are around 37mm dia and the MPi head is around 34mm dia, from my post above,37mm dia -34mm dia =3 divide by 2=1.5mm)

One question though - is that a used 135 head? If so, why is the step inside the manifold gasket so clean?


"I have a 05 135 Tf in at the moment for head work" From my post above
It ain't very old Rob and pay attention;-)
mike

"Posted 23 February 2006 at 23:21:35 UK time
Rob Bell, North London
Mike - I am astonished! I can't quite believe that Rover would deliberately mismatch the plenum to the head like that... amazing for all the wrong reasons"

Rob, Iam astonished! I can't quite believe you would believe that they wouldn't!!!
On a plus note they have done an angle job on the inlet valve seat, nothing outstanding but probably gives a torque gain:-)..just about balences out the ports mis match torque losses 8-{
This might have some bearing on some of the complaints people have has about low speed smoothness something the stock MPi never suffered from.Bigger ain't necessarily better in this case.
mike

LOL thanks Mike - will try and pay better attension sir! ;o)

The mismatch is alarming - presumably the negative impact is offset by some benefit of the new manifold - otherwise why not continue to use the still-available plastic plenum?
Rob Bell

Why indeed?Better heat sink against HGF?? LOL. Perhaps RR graphs may show the reason.Anybody got some of the 1.8iMPi and the 135TF to compare?
mike

Yes, I have - but that picture is clouded by the fact that the TF135 uses warmer cams.

What would be useful is to RR an MPi engine (standard 120 or 135), trying both manifold types. Trouble is, this is quite a lot of effort - will anyone be able to do this?

Unfortunately, the TF135 head I've got has been ported, so how relevant this is to standard heads, I am not sure?
Rob Bell

This thread was discussed between 16/02/2006 and 28/02/2006

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