cam pulleys
- Thread starter parksy340
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U really need some quite special cams to justify adjustable cam gears. The intake side is already adjustable (VTC) so locking the intake side to a specific angle is for race cars only (no VTC allowed or something like that).parksy340 said:
Adjusting the exhaust cam gear can indeed give you gains in some areas depending on the cams, but you will always loose power elsewhere and finding the right angle for the exhaust cam can be really time consuming.
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In the past I would have gone with Tdi north without question , but lately I am hearing more stories of them not quite being up to par , I would definitely consider RDT. But worry about his possible lack of experience and there is always EPS ( Dave Rowe) who is a mapping master and although not a kpro specialist would do a fine job, while I think mase would be good as well the amount if maps they try and achieve in a short time also bothers me ( however I have only ever heard good things )
At the end of the day the map will make no more power whoever does it, the engine internals are the important bit, the map only optimises the fuel and cams etc all to work in harmony together there are no real "tricks" to do that it just needs to be thorough ,
At the end of the day the map will make no more power whoever does it, the engine internals are the important bit, the map only optimises the fuel and cams etc all to work in harmony together there are no real "tricks" to do that it just needs to be thorough ,
12.5:1 is quite high compression, who is building your engine a they will need to think about valve to piston clearance and this can be time consuming. Are you skimming the head or using high compression domed pistons?
A good map will make the most of the engine, a bad map will stop you getting the most out of the engine and remember it's not all about peak power.
Is this a track car?
A good map will make the most of the engine, a bad map will stop you getting the most out of the engine and remember it's not all about peak power.
Is this a track car?
DopeDragon
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Mase has mapped my car and I am using Skunk2 Stage3's (version 3). Compression is also at 12.5:1 but I have bored it out to 87.5mm with Wiseco pistons and K1 forged rods. Also have Skunk2 titanium valves, Skunk2 springs, retainers etc...
I didn't bother with the cam gear, after researching on clubrsx and speaking to Tom (TGM), the conclusion was that cam gears are a waste of money and cause problems.
It is currently making 214BHP at the wheels, I honestly think my Maximworks manifold is restricting the power. Although it is a quality part, I reckon a Toda or Buddyclub would unleash its full potential.
I didn't bother with the cam gear, after researching on clubrsx and speaking to Tom (TGM), the conclusion was that cam gears are a waste of money and cause problems.
It is currently making 214BHP at the wheels, I honestly think my Maximworks manifold is restricting the power. Although it is a quality part, I reckon a Toda or Buddyclub would unleash its full potential.
DopeDragon
Advanced Member
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Very good point about peak power, a good driving machine is not purely based on peak power. Torque and smooth delivery are very important and the mapper will influence both areas significantly. Also, dynos can be configured to flatter the performance figures. In my opinion you will only appreciate a cars performance by getting behind the wheel. ab20000 is absolutely correct with regards to peak power and mapping. Other factors that need to be considered are tolerances of the various parts, fuel economy and driving style. A weekend trackday car should be mapped differently from a daily commuter and the mapper should be aware of this before making any changes to your ECU.
pulpmelon_r
Advanced Member
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What was your baseline run on that dyno before fitting / tuning cams?DopeDragon said:
I would be inclined to think about the whole package your running, what diameter intake and exhaust for example?
tricker_luke
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I'm having my car mapped by RDT in Doncaster next weekend. The guy sounds like he knows what he's talking about anyway after a good few conversations with him to make sure I understand everything etc.parksy340 said:
He also uses one of those dynos that attaches to each wheel hub, rather than a rolling dyno, so that will be interesting to see it being used.
I will let you know my experience after it's been done.
pulpmelon_r
Advanced Member
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I hope your configuration works out, I must admit sk2 stg3 may have too much duration for a 2L
Best of luck though
Best of luck though
No lack of experience here!C&S Evo7 said:
Parksy, Dependant on which cams you go for, the VTC mechanism can either be removed in exchange for a fixed set of adjustable pulleys or you can modift the VTC actuator to limit the cam advance for your application which is the best option. ...since these standard engines can advance the cam upto 25*degrees you may not want that with a much higher duration cam. The VTC mechanism is a wonderful creation, so why not use it! When you can get really high fuel economy an great power + smoothness, then why not.!? If you do use it though make sur eyou check the adjustable cam pulley centerline against the limited VTC actuator centreline as Ive seen it many a time when aftermarket pulley centerlines are not the same as the OEM. Never assume!
The best way to check the clearances on the K-series is for your engine builder to use an adjustable cam pulley on the intake side as well and dial the cam in at the 1mm lift datum‘s with the vtec mechanism locked either by v.high air pressure (this doesn‘t work if you have a lot of miles on the engines! In which case you lock the mechanism mechanically. Along with the use of low pressure valve springs piston to valve clearance can be checked very simply. if you're using a quality DTi (I only use Mitutoyo instruments myself here!) put it in difference mode when you‘re at each 1mm datum (opening/closing) then simply press down on the roller rocker assembly with your index finger until it touches the piston, Then write down the indicated clearance on the DTI. This can be different across the cylinders so it is worth checking on every one. (e.g. bentcrankshafts (seen this on the skyline engines a couple of times!/badly manufactured cams etc.)
There‘s a common misconception that claying an engine is the way to check the piston to valve clearances. This isnt the case, it is an outdated P2V checking method but its real purpose is for RADIAL clearance. I.E. making sure the valve fits into the pocket of the piston, and with oversized valves this is often a minor issue that needs to be addressed. In which case you have a special 'scribe' punch made of an old valve stem machined to a point. With the piston at TDC you make a valve centre-point on top of the piston and then dis-assemble the engine again. Take the pistons to the machine shop, with your valves and specify the radial clearance you require. Bearing in mind that as your valve-guids wear over time you have to have a safety margin slightly exceeding the Honda valve-end-play service limit!
Another element of confusion here is the compression rating of a piston. Pistons don‘t have compression, but engines do. Pistons do however have displacement volumes. The static compression ratio is the result of the displacement of the piston in relation to the deck surface of the engine, the heads combustion chamber volume along with the along with the swept area of cylinder (basically largest volume too smallest volume in the chamber). There is also some finicky details that come into play like the area above the top ring to the crown surface of the piston and the volume this space has. The only accurate way to work-out the compression of an engine is with a burette. So you can literally measure the volume of the heads combustion chamber & the displacement or volume of the pistons dome accurately in order to calculate the static compression. Alot of piston manufactures assume the volume of the heads combustion chamber being stock along with stock valves and a stock spark plug. So there can certainly be a great deal of variation between advertised and actual. Never assume anything with engines as that will be your first mistake. Everything‘s measurable and quantifiable.
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No lack of experience here!EK9turbo said:
You are still an unknown to us hence the word " possible"
you certainly seem to know what you are talking about reading your posts since my original comment and it will be great to get another decent mapper in the UK, peoples choice has been limited in the past
top post above by the way. :xcheers: