cams with FI - who has done it?

16bit · Postby **16bit** » Thu Dec 20, 2007 10:52 am

Just wondering what kind of a difference I would get with some 805c's and my supercharger setup. I have an aftermarket computer so i can make pretty good use of them tuning wize. Would i need to get adjustable cam wheels? And if i did would I need to re do my springs, retainers, valves etc?

hamish71 · Postby **hamish71** » Thu Dec 20, 2007 2:22 pm

I will support this query, as I have had no luck myslf. I have researched this as thoroughly as I can, for my car, which is a 2001 NB, with SVT. The research can be summarised as follows:

There are no reputable manufacturer cams available for the 2001 NB. The only one that comes close are elsewhere on this forum, (and I cant find it...Japanese made, not tomei, or any of the better known brands) and they are not yet \"proven\", by which I mean, widely purchased and raved about.

Tighe here in Australia said they would weld/regrind mine for about $900, but again, I can find no evidence to support this as an advantage.

But, the clinchr for me, was talking to a bunch of well known and experiences MX5/miata engine builders. I eventually got hold of the well known Corky Bell, and put it to him. His response was pretty much, unless you are running Bonneville, you are wasting your time. The stock cams work fine with FI. Flow your head, o/s valves, titanium springs if you must, and that will be plenty.

That statement was well supported by a number of other miata engine builders in the USA. Good enough for me....

adamjp · Postby **adamjp** » Thu Dec 20, 2007 2:23 pm

I would talk with Tighe to determine the best grind. Improved cams will improve your power charateristics.

Adjustable wheels should not be necessary, nor should new valvetrain components if you don't go for a too large lift.

adamjp · Postby **adamjp** » Thu Dec 20, 2007 2:25 pm

As hamish has pointed out, other changes may deliver better improvements.

Garry · Postby **Garry** » Thu Dec 20, 2007 2:42 pm

When they did the SP they used the VVT to create the \"turbo\" cam they were after. It was one of the big gains of switching from the 8A to the 8B.

AB7 · Postby **AB7** » Thu Dec 20, 2007 2:52 pm

I know Maruha/ Tomei make the only off the shelf VVT Cam for NB8B. Its for N/A though not F/I

Matty · Postby **Matty** » Thu Dec 20, 2007 8:18 pm

Garry wrote:When they did the SP they used the VVT to create the "turbo" cam they were after. It was one of the big gains of switching from the 8A to the 8B.

The implication from this is that there's lots of VVT tuning required when you change airflow characteristics (eg by turbo or cams). Probably not worth it unless you can sell a lot of ECUs...

Russellb · Postby **Russellb** » Thu Dec 20, 2007 9:26 pm

I have fitted a set of cams ( NFI on the specs ) to My Old Mans NA6
with a Turbo. It driveslike a STD car but Goes Mental from 4500 RPM
to 7500 RPM . Haven't had it on the Dyno but will be putting Cams in My
New turboed NA8

.

There are gains to be made from fitting Cams but as is the Norm there
is a loss of bottem End HP.

16bit · Postby **16bit** » Fri Dec 21, 2007 8:47 am

thanks guys - might be money better spent on an lsd or roll bar at this point.

Uncle Arthur · Postby **Uncle Arthur** » Fri Dec 21, 2007 3:25 pm

I picked up a replacement donk with HKS 264 Inlet cam and regrind exhaust cam, which goes nicely with the TD04 setup on my 91 1.6.

There is a noticeable difference between the upgraded cams and the stock cams with the same turbo.

4sfed5 · Postby **4sfed5** » Sat Dec 22, 2007 7:23 am

i would have thought that fitting adjustable wheels to the original cams would get better bang for buck as a turbo relies more on cam timing than lift to get the job done correctly.

Sean · Postby **Sean** » Tue Jan 01, 2008 6:38 pm

4sfed5 wrote:i would have thought that fitting adjustable wheels to the original cams would get better bang for buck as a turbo relies more on cam timing than lift to get the job done correctly.

Indeed, you need to know exactly where and wht gains you are after before messing too much with cams, adjustable gears give you a great idea of what you can achieve on bth sides, I was making great top end power with 20 degrees (can't remeber if it was advanced or retarded) but it made no torque at all, adn would barely even hill start unless you had 3000rpm in it.