NA cam delete + other interesting stuff

There are at least 3 things I don’t fully understand in this world, spark plugs, camshaft design and women.

Granted, I’ll never understand women! Time permitting I may one day grasp something of the various types of spark plug technology and their suitability for various levels of high boost performance engines. But for now at least, spark plug technology remains a mystery.

• Should I buy Silver, Copper, Gold, Iridium, Platinum or Nickle style plugs? Silver they say is the best conductor and Nickle, the least conductive.
• What heat range should I be looking for in a mildly boosted engine and occasional track day use? (by mild, lets say 24psi) Some say go a stage cooler, others say beware it can cause fouling.
• Does the manufacturer make a difference and if so which one should I buy? The more popular brands being NGK, Bosch, Denso, AC Delco and OEM.
• Should I believe it when one site says Iridium is best, and another says Copper core is best?
• What should I do with the thousands of opinions from online forums that seemingly contradict each other? Good lord, am I talking about women or plugs, I forgot!

Or is this some kind of marketing conspiracy to produce multi level pricing strategies for higher priced, so called, better performing products?! I think that’s more of a given than a genuine question.

Ok so here is what I can tell you and what it relevant to my build! When talking plugs, too large a spark plug gap will likely contribute to a miss fire at higher boost levels, say 20psi+. My personal experience would tend to suggest that .022″-.025″, converted to proper form of metric measurement .56 to .64 mm, is the best spark plug gap for a mildly boosted engine such as Ovlov’s and will minimise miss fire at 24psi.

As for the brand and type of core/electrode, yes there are significant variations. For example, your Iridium’s will last about 10 times longer than your Copper’s. Everything else is just too confusing!

Double Platinum

I should add that for the last 15,000ks I’ve been using a Bosch F5DPOR plug. Originally designed for Audi performance engines, these Double Platinum plugs are spoken of very highly, aside from some concern that the Double Platinum tip has been known to separate in very high performance installations i.e. 400hp+. Far more devastating a reality than I make it sound with these few simple words!

The reason I’m talking about this is we seem to have developed some spark blowout issues again, now that the old girl is running sweetly. And by sweetly I mean, producing some fairly high boost at an earlier onset than previously. And the reason for this is two fold!

Having resolved my exhaust manifold boost leak issues I turned the boost up. Secondly, I removed the NA cams and reinstalled the OEM turbo cams.

Reinstalling the turbo cams lead to a surprising holy crap moment concerning a performance change. The reason for removing the NA cams was the result of my feeling I’d lost a little too much low end HP and torque since installing the larger Mamba GTX 3071R Turbo.

When I originally undertook the NA cam swap a couple of years back I was still using the TD04 turbo, which produces a nice level of boost in the lower to medium rev range. The whole point of the NA cam swap at the time was to extend the boost range to higher RPMs via the different design and a retardation of the intake cam. At that time I didn’t feel a significant loss of power in the low and mid range. In fact it felt a little better.

Anyways, with the Mamba feeling a little laggy at the low end and my never ending search for performance gains, I went back to the original Turbo Throttle body; No significant change, zilch, none, aside from feeling like the throttle was a little more progressive or less sudden, so far as daily driving was concerned. WOT did feel a little less exhilarating!

Once more I reverted to the larger throttle body and this time reinstalled the Turbo cams with their original settings; Instant change! Low end response much improved. The ridiculous thing is that boost onset feels like it’s come back by about 500rpm. Silly to think that this would make such a difference.

I guess it kinda makes sense given the lower boost levels of the Mamba at lower rpm, and that the OEM Turbo cams with their more advanced timing setting will of course improve things in the lower RPM range. The downside will be a loss of power at the top end, and potentially some detonation related issues. But given the Mamba is able to pump a shite load more air I figure the top end losses won’t be too great.

Perhaps there is more to it than this. Perhaps it has something to do with cam overlap, another mystery which I’ve not fully understood, though the article on the attached link does provide some clarity! LINK.  Either way I know what I can feel in terms of a performance improvement and for a daily drive I’m going to like this quite a bit better, and am already.

And this my friends is why we are talking about spark plugs and the best plug to support mildly modified boosted engines, experiencing spark blowout. The gap, the gap, just focus on the gap!

I gotta add as a final note that the 850 Turbo article which had me rethink the NA cam swap was a well know modified 850 sedan referred to as Yellow Peril, in which the writer referred to a power loss with the NA cams. He too was using a turbo somewhat larger than the TD04 designed units.

I know you guys like pictures of car stuff!

Oh and by the way, the plugs I chose to use are NGK Iridium Spark Plugs BKR7EIX. They tell me that you need to be careful when gapping them as the centre electrode is quite fragile.

Happy modding!

 

 

More Track Day Antics

The recent track day Ovlov participated in at Wakefield Park was the least successful of all thus far with a manifold leak at the turbo flange causing a few issues which I just wasn’t able to sort at the time. God only knows how or why one nut decided to undo itself from the manifold flange but given this is her first time out since a major bunch of mods, some minor issues were not unexpected.

Just to review, since last outing we’ve installed the M66 gearbox with MFactory LSD, the Mamba GTX3071R turbo, 550cc injectors, an update to the ECU, some Bilstein rear struts, subframe bushings, rear outer suspension links, full bodied aluminium radiator, Hi flow cat, larger throttle body from the NA series, 511 MAF, and I’m sure I missed something in that. Of course this included bunch of exhaust welding and a new dump pipe too.

Thinking about it now I’m surprised we didn’t have more issues than a popped nut on a manifold flange.

On the day I did manage to complete around 20 laps before choosing to bow out. There were 3 significant changes to her performance since last outing, the most notable being the LSD. The improvement in this regard was fantastic and although we could still manage some wheelspin exiting a corner under load, we were not even close to the previous degree of lost traction of an inside wheel with the open diff.

Wakefield Park

Gone was the need to feather the throttle in the hope of minimizing burning rubber and overheated tyres. I’ve not driven any other high performance rear wheel drive vehicle in a similar track scenario so I’ve nothing to compare it with but would summarize by saying that the high horsepower front wheel drive disadvantage was virtually nullified as a result.

The second notable change was a loss of torque in the mid range due to the turbo upgrade. Sure we could certainly manage that situation by running 1000rpm or so higher at various points but in this regard, the Owens Hybrid turbo mid range torque was notably absent. Perhaps this is also associated with running the larger NA series throttle body, suffice to say, pulling out of corners in 3rd at a lower RPM required some additional planning, with 2nd gear being a better option under some circumstances.

The final notable change was the endless supply of power all the way to redline. Although the former Owen Hybrid produced nice power it did tend to flatten out somewhat at around 5000rpm. This was not evident at all with the Mamba and when I have a chance to get this thing on a dyno it should be fairly obvious to see on a dyno chart. Going full throttle down the main straight of Wakefield Park she felt a little too fast for my liking, in part because I really didn’t have time to settle in and find the limits of the car and my confidence or skill level.

With the Mamba I’ve wound the boost up a little more and we are pushing up to 26psi. Having said that, 15 psi with this turbo and the improved airflow it remains very quick. With the remapped ECU she feels good, no longer running rich at the bottom of the rev range and a little more peppy in the mid range. I always pay attention to the colour of the carbon on the exhaust tailpipe and following the track day she was a perfect tan brown, a reasonable indication of fuel mixture.

Ovlov handles great for a heavy old girl, lots of body roll and a little slow to turn in. As I stated in a previous post, after driving my sons MX5, she feels a little like a boat. Of course the next most obvious change would be a set of coilovers but I’m really struggling to bring myself to that point given that she remains a daily drive on some pretty crappy ACT and NSW roads. I get the feeling we will make that change at some point but I’ve not yet convinced myself when that might be.

Aside from the above, I am still thoroughly enjoying her as a daily drive and the occasional blast at WOT brings a smile to my weary bones.

Until next time 🙂

The highs and lows of the M66 gearbox

There really aren’t too many lows to talk about with regard to the M66 install. I just wanted to write a tabloid style lame heading as the title of this post.

The gearbox swap has probably presented the most challenging aspect of the latest round of mods, but it’s done now and at least if I ever need to replace the gearbox again, it will be much easier next time round.

There are a couple of things still bugging me about the install but it’s nothing serious. When the car is idling there’s a bit of a rattle coming from the clutch plate area and if I’m correct, I’d say it’s the springs in the SD693 friction disk chattering. I vaguely recall that the springs were a little rattly in the disk pre install but wasn’t paying particular attention. It’s only audible at idle and low engine speeds and disappears as soon as the clutch is depressed, hence my conclusion as to the cause.

As to the highs of the install I was pleasantly delighted to find that 6th gear in the M66W (V50 T5 gearbox) provides for a lower rpm kilometer per hour than the M56H. The  6th gear ratio is .65:1 compared to .70:1 for the M56. In plain english what that means is at a speed of around 100klm per hour, engine rpm is effectively reduced by about 10%.

That might not sound like much but in my case it’s significant. At the state limited highway speeds of 110 kph Ovlov’s cheap and cheerful OBX exhaust was always a little boomy. That has all but disappeared. I suspect the installation of a catalytic converter may have also added to a small change in the exhaust note.

With regard to the feel of the M66, it is less notchy through the gears, feels more refined and ratios for 1st through to 4th are great for around town. The new clutch utilises an internal slave cylinder and feels lighter and a little more responsive than the old external slave. The downside of course is that a failure with the internal slave will require removal of the gearbox.

The other aspect of the M66 upgrade was the inclusion of a limited slip diff. This has all but eliminated wheel spin during straight line acceleration. Having said that, I’m sure she could break a good wheel spin in 1st and 2nd if you tried but I’m just not at the point of pushing those performance boundaries. I don’t want to break her just yet!!

Interestingly she can still wander over the road a little on hard acceleration, I was hoping that this would have reduced somewhat but at this point feels much the same. This is probably partly related to the camber and toe out which is setup for track work. I guess we’ll really get to see how the LSD effects performance and handling at a track day in the very near future.

For those interested in the M66 swap, it was worth all of the pain, but I gotta say that there is quite alot of it. For the would be do it yourselfer it’s a great project, but I doubt very much if you’re ever going to pay anyone to undertake this mod given it’s scale and complexity.

I did list the required mods in a previous post but here it is again if anyone is interested.

• A new clutch plate to match the change in the spline on the M66 gearbox. The Sachs SD693 clutch plate can be utilized in conjunction with the existing R series pressure plate. Note – 2019 Changed clutch plate to M-Pact 381087ST15, primarily due to annoying rattle in the Sachs disk.
• Rear engine mount on the Passenger side (AU) of the engine will require fabrication and installation of a new bracket.
• The existing hydraulic clutch line will need to be replaced/modified, as the M66 utilizes a different style of slave cylinder.
• Gear shift cable locating bracket will require modification or fabrication.
• One of the gear selector levers atop the gearbox will require a change if you are using the original 850 gearshift mechanism.
• A used M66 will most likely require a replacement thrust bearing assembly to be installed at the same time.
• The speedo cable electrics will probably need to be tapped into the front wheel ABS line.
• The airbox is now a really tight fit given that the shift levers on the M66 sit higher. Easy option is install a POD filter otherwise it gets a bit squeezy, but you can make it work!
• MISC – When using the 850 series gearshift assembly there is no shift lock mechanism to prevent accessing Reverse gear. In my instance I’ve attached a piece of spring steel to place extra force on the shift mechanism requiring reasonable effort to move beyond 5th/6th and access Reverse. Looks a bit clumsy but works perfectly! https://youtu.be/aCLUMz_wZnY
• Oh and I forgot, most importantly you’re really gonna want a gear shift knob which has 1-6 and R on top of it, to impress your passengers. Here’s mine! Impressive hey! 🙂 If you’re ever wondering how to get the old gear shift knob off, don’t ask me, I had neither the patience or interest but I do have an angle grinder!

I think that covers most of it…..Happy modding!

FOOTNOTE – In June 2019 I replaced the Volvo M66 with an Ford Focus M66 gearbox. It is worth mentioning that there was a slight variation in the overall length of the Ford Focus Gearbox, the result being that approx 5mm of the box came to rest on the LH section of the subframe. Initially this caused some consternation as to the cause of excessive vibration. The 5mm section which was protruding onto the the subframe was able to be cut away from the gearbox without issue.

Out with the M56 5 speed and in with the M66 6 speed with LSD

The M66 all cleaned up and waiting to install LSD

That’s gotta be the longest title for a post on this blog yet, and in like fashion this particular modification will rate as one of the more significant aspects of Ovlov’s  evolution.

When considering this change I have to admit wavering on the issue for some time. The existing M56H is a great gearbox. It’s completed 260,000klms and 130,000 of those whilst in my care. It remains in excellent working condition and will continue to do so for some time more yet. The M66 won’t give her a better top speed and may not even be as robust as the M56 and so you might wonder why proceed in this direction.

One reason being my concern around availability of another M56 should this unit eventually fail and particularly as she’s been spending more time as a track vehicle. As such when the opportunity arose to pickup an M66 from a V50 t5 for a bargain price, I could hardly refuse. There are increasing numbers of the M66 gearboxes out there and decreasing numbers of M56’s. It makes sense to make the change now and find out exactly what’s involved and have access to further M66 stock if required.

I know that M56 and M59 gearboxes can still be found, but the reality is that they come with the car. i.e you gotta buy an old manual 850 or s/v 70. This is increasingly problematic as it takes considerable resources to find, buy, store and strip parts from these old girls.

The fact that Ford also utilized the M66 box in it’s Ford Focus XR5’s, also known as Focus ST225 outside of Aus, adds to the availability of boxes and associated parts. For example, the Mfactory LSD intended for install in this upgrade is not found anywhere listed for Volvo vehicles, only Ford Focus.

The LSD is an aspect of the upgrade which I’ve been very keen to address and the additional traction will be warmly welcomed. I had learned to manage the limited traction of the open diff in track day events but this has without a doubt, limited the capability of this car. How the newly installed LSD will ultimately effect performance and drive traction will be interesting to experience and I am certainly excited about getting to that point. In terms of road use, it will I hope be a nice change not being caught unaware with sudden changes in direction under hard acceleration. It can be a little scary at times.

And so to kick this all off I’m going to post around this modification in a few stages. This post is also a pre cursor to the actual change and for anyone out there whose already undertaken this swap I’m listening with open ears. I’ve been researching this for some time, at this point the only unknown relates to the fabrication of a new engine mount on the rear passengers side (au). Other than this I believe we are good-to-go.

Given that this is the 2 wheel drive M66 swap, and we are swapping into a vehicle which has an existing manual gearbox, and there is no dual mass clutch plate to be concerned with, and the existing M56H has no inbuilt speed sensor, the process is somewhat simplified.

What is required?

• A new clutch plate to match the change in the spline on the M66 gearbox. On good advice I’m told that the Sachs SD693 clutch plate can be utilized in conjunction with the existing R series pressure plate.
• The existing hydraulic clutch line will need to be replaced/modified, as the M66 utilizes a different style of slave cylinder.
• The gearshift lever assembly will require some fiddling as there are differences in the way existing cable connects to the gearbox, but again, others have been there before me and completed some modification  to existing brackets without too much difficulty.
• The fitting of the Mfactory limited slip diff will require that the diff bearings be replaced and some new gearbox drive shaft seals installed.
• The M66 will require an OEM thrust bearing but this is simply because the old is worn out. Not a modification as such.
• The rear engine mount on the Passenger side (AU) of the engine will require fabrication of a new bracket and mount.

While all of this is going on, long overdue replacement of the sub-frame bushes will take place, a job I’ve been wanting to address for ages 🙂

I thought I’d keep a running tally of items on this part of the project, including links and prices which may prove helpful to anyone wishing to undertake this same modification.

• M66 Gearbox – 2006 V50 T5 FWD – Sydney Motor Recyclers $80 (yep, it was a bargain buy)
• MFactory Helical LSD – Suitable for Ford Focus ST225 M66 6 Speed –  Of note, Mfactory only list this unit for the Ford Focus XR5 (AU) or St225 (overseas) but I did confirm it’s compatibility. Purchased from Diff Lab $1000 au
• Sachs SD693 Clutch plate – Purchase from Rock Auto $70 au
• Sachs SB60223 Release Bearing and Cylinder Assembly – Purchase from Rock Auto $120 au
• SKF Differential Bearing x 2 – SKF 32008 xt9/q or National NS32008 – Source from Rock Auto $25 each. (I noted that some M66 gearboxes utilize a larger diff bearing 32010 x. I suspect this larger bearing must have been for later model m66 gearboxes. Best to check what’s in your gearbox before ordering)
• Gearbox Input shaft seal -Part# 8675580 – FCP Euro – $15
• Drive shaft axle seals – Part# 6843481 – FCP Euro – $7 each
• Modification of existing clutch line – again, from a local supplier with cost unknown TBA

At this point in time, aside from the process of purchasing the required items above, I’ve opened up the M66 box to inspect condition which looks great. The fitting of the LSD looks to be quite straightforward with the only significant consideration being the need to maintain appropriate spacing tolerances when fitting new spline bearings, I think!

Footnote – Some may be wondering why the MFactory helical LSD when the common options are Quaife, Wavetrac, or Gripper.

• I like to be different. 🙂
• I found a local distributor.
• They seem to have some genuine street cred in the performance sector.
• The price was about 20% less than nearest rival.
• They claim superior product as a result of manufacturing techniques.
• I could find no online threads to suggest they are crap, quite the opposite.

I guess I’ll get to find out in a several weeks but in the interim here is a little more info which may be of interest.