Cams.. Discussion, which may lead to a cheap group buy

[maxwolfie]

After recent discussion last night on the fish and chip run with a fellow MX-5'er that can possibly get cams cheaper I have suddenly become much more interested in getting some nice cams in!!

Questions:

1. I've made a small list of manufacturers... can you rattle off as many cam brand names as possible?? (ones that have NA6/NA8 shafts pls)

2. I'm looking for something fairly aggressive (I've had mild cams in a swift GTi before and wasn't happy - I went and exchanged them for some craazy ones and they were so much fun!!) ... Any recommendations??

3. Who here has aftermarket cams? How are they? do you have adj cam gears as well? How well does the 1.6 take to them?

I'm sure I'll think of more questions as i think about it more

[Babalouie]

After recent discussion last night on the fish and chip run with a fellow MX-5'er that can possibly get cams cheaper I have suddenly become much more interested in getting some nice cams in!!

Questions:

1. I've made a small list of manufacturers... can you rattle off as many cam brand names as possible?? (ones that have NA6/NA8 shafts pls)

Tomei, Toda, HKS (NA6 only), Tighe, Mazdaspeed, err...

2. I'm looking for something fairly aggressive (I've had mild cams in a swift GTi before and wasn't happy - I went and exchanged them for some craazy ones and they were so much fun!!) ... Any recommendations??

Toda make some pretty wild grinds. Tomei/HKS are at the milder end of the range.

3. Who here has aftermarket cams? How are they? do you have adj cam gears as well? How well does the 1.6 take to them?

Pick me! Pick me! Yeah, I got the gears too but they are set at the factory timing at the moment (which was the recommendation with the cam anyway). I have the Tomei Poncams...love them, they have transformed the car. 'Shame they don't do them for NA6.

I'm sure I'll think of more questions as i think about it more

This is interesting....Clicky The Maruha "new" F-cams are just the Tomei Poncams re-branded by the way...

[green_comet]

whats the the biggest cams you cna run on a standard cmputer?? I was looking at getting some, if you run something like an apexi safc, can u use wilder cams with the standard computer?

[CT]

As soon as you change your cam profile, you really should have something that can retune your air fuel ratio, ie interceptor or full ecu. Main reason being that you are changing the engines requirements for fuel and timing. That said, some cams will work within the factorys tuning spec but they will generally be milder cams such as the tighe 805C.

[maxwolfie]

I am also looking for some sort of piggyback or complete reprogrammable ecu in order to get the most out of the cams as well.

I'm not looking for something mild, looking for something with a fairly aggressive profile.. probably something at the end of the "streetable" range bordering on a race profile, as described in most of the manufacturers catalogues...

Current *relevent* mods are: RX7 AFM/pod, standard headers with 2" trust exhaust, bigger leads.. with 14-15 adv. timing

[Babalouie]

whats the the biggest cams you cna run on a standard cmputer?? I was looking at getting some, if you run something like an apexi safc, can u use wilder cams with the standard computer?

My Tomei cams are 252/256 duration with 9.2/9.5mm lift. That's pretty conservative on duration (stock is 235/248) but it's quite wild on lift. They're intended for use with stock ecu, and they do seem to work pretty well without any ecu changes.

On the stock ecu settings it only made 3rwkw less than after the piggyback was tuned, and to drive it felt largely the same except you could feel some very minor flatspots here and there so it revs out more smoothly with the "tuned" settings. I reckon a piggyback is all you would need to make the minor tuning adjustments to get it perfect, but a fully programmable ecu would allow you to raise the redline a bit to fully utilise the cams potential. About 7400rpm would be all that you need.

[maxwolfie]

whats the the biggest cams you cna run on a standard cmputer?? I was looking at getting some, if you run something like an apexi safc, can u use wilder cams with the standard computer?

My Tomei cams are 252/256 duration with 9.2/9.5mm lift. That's pretty conservative on duration (stock is 235/248) but it's quite wild on lift. They're intended for use with stock ecu, and they do seem to work pretty well without any ecu changes.

On the stock ecu settings it only made 3rwkw less than after the piggyback was tuned, and to drive it felt largely the same except you could feel some very minor flatspots here and there so it revs out more smoothly with the "tuned" settings. I reckon a piggyback is all you would need to make the minor tuning adjustments to get it perfect, but a fully programmable ecu would allow you to raise the redline a bit to fully utilise the cams potential. About 7400rpm would be all that you need.

Hey babs.. Do you know of any piggyback+cam packages that are commonly sold by performance places that suit the NA6??

I would like a Link or something similar, however I dont think I would be willing to fork out that much $$$.... However I realise I'll need at LEAST a piggyback in order to get more aggressive cams to work.

[Bevan]

Greddy EManage?

[Babalouie]

whats the the biggest cams you cna run on a standard cmputer?? I was looking at getting some, if you run something like an apexi safc, can u use wilder cams with the standard computer?

My Tomei cams are 252/256 duration with 9.2/9.5mm lift. That's pretty conservative on duration (stock is 235/248) but it's quite wild on lift. They're intended for use with stock ecu, and they do seem to work pretty well without any ecu changes.

On the stock ecu settings it only made 3rwkw less than after the piggyback was tuned, and to drive it felt largely the same except you could feel some very minor flatspots here and there so it revs out more smoothly with the "tuned" settings. I reckon a piggyback is all you would need to make the minor tuning adjustments to get it perfect, but a fully programmable ecu would allow you to raise the redline a bit to fully utilise the cams potential. About 7400rpm would be all that you need.

Hey babs.. Do you know of any piggyback+cam packages that are commonly sold by performance places that suit the NA6??

I would like a Link or something similar, however I dont think I would be willing to fork out that much $$$.... However I realise I'll need at LEAST a piggyback in order to get more aggressive cams to work.

Yeah, I reckon any wilder than 256 duration and some sort of ecu-fiddling would be necessary. I use an Apexi SAFCII, but Greddy Emanage would work just as well. If you want to go to say 272 cams then definitely you would need some sort of full programmable ecu so that you could raise the redline to enjoy the top end. Even with my mild cams, the real power peak is about 200rpm above where the rev limiter is

Does anyone know if the JDM ECU for NA8 has a slightly higher redline? an extra 200rpm is all I need

I'm not aware of any packages out there...at least not in AU anyway.

[Babalouie]

Second that...any cam more aggressive than say a 264 would probably be beyond the capabilities with a stock ecu/piggyback combo. Your NA6 has a flap-door afm though, so it might be still vaguely ok.

[adamjp]

I would be interested in more agressive cams for my NA6.

Please be warned that my research indicates that anything over 8mm lift will need the HLA buckets machined to stop cam lobe meeting solid head material.

Keeping the cam lift at 8mm, a 257 Inlet/259 Exhaust seem to offer the best returns on my head specs (not stock). But if you are willing to go to 10mm lift, the Tighe 845C appears to be good and strong.
I have a copy of Dyno2000. Not as good as SportCompact, but it is what I got. http://www.proracingsim.com/dynosimSCmainpage.htm

Cams at a good price would be welcome. I am sitting on a Unichip to go into the NA6, and putting them in before the dyno session would be nice.

IMHO if the cams are built right, you don't need adjustable cam sprockets.

If someone is willing to host the picture, I can post a computer dyno sim of a stock MX5 against one with 845C cams. Perfectly correct? No way. Better than guessing? Yep.

[Sean]

If someone is willing to host the picture, I can post a computer dyno sim of a stock MX5 against one with 845C cams. Perfectly correct? No way. Better than guessing? Yep.

Here tis....

[Babalouie]

Please be warned that my research indicates that anything over 8mm lift will need the HLA buckets machined to stop cam lobe meeting solid head material..

That's true, but Tomei got around that by machining cams with a smaller base circle. That's how they get their cams up to 9.5mm lift in my case, and I believe that in testing, they managed to accomodate up to 10.2mm in this manner but it didn't idle well or something. So I guess it depends on the brand.

Keeping the cam lift at 8mm, a 257 Inlet/259 Exhaust seem to offer the best returns on my head specs (not stock). But if you are willing to go to 10mm lift, the Tighe 845C appears to be good and strong.
I have a copy of Dyno2000. Not as good as SportCompact, but it is what I got. http://www.proracingsim.com/dynosimSCmainpage.htm

Cams at a good price would be welcome. I am sitting on a Unichip to go into the NA6, and putting them in before the dyno session would be nice.

IMHO if the cams are built right, you don't need adjustable cam sprockets.

Agreed, mine are adjustable but the recommended timing was same as stock, so they're superfluous at the moment, although I am going to fiddle with them on the dyno one day just to see what happens. Your proposed cam specs sound good tho....very similar to NA6 HKS specs I believe.

[CT]

Big lift and larger base circles give me plenty of grief. Don't forget, that for real valvetrain stability, consider solid lifters. I can supply necessary components to convert HLAs to solids. I run these in my race car. That way HLAs won't limit your upper rpm power.

Also, for 10mm lift, I'd be looking into better valve springs too. Flying Miata uses Cosworth springs which I can certainly recommend as being up to the job.

[adamjp]

All,

I would take the numbers with a grain of salt. The poweer curves and their relationships to each other are probably pretty good. I seriously doubt that an NA6 donk could do 180hp (130kw ish) without alot more work than mine has. I mean the stock one is 125hp (93kw)! I could tweak the graphs around a bit to be more faithful to the real numbers, but we are more interested in the relationship between the various stages of development and their peak points.

The MX5-845C-Stock and MX5-Stock-Stock models were standard NA6 head flow and induction, 9.4:1 compression and HP Headers with mufflers. The variation was the camshaft specs.

The MX5-845C-Ported is my NA6 with a ported head, stock induction, 10.5:1 compression, small tube headers with open mufflers. This effectively replicates the setup of my car.

The head flows are as measured on a flow bench test of my head when I had it worked.

The induction is 165cfm, as published on solomiata for the 1.6 flapper door AFM.

HP headers and mufflers replicate the stock MX5 'extractors' and exhaust system.