1990 1.6. i am going to install a begi kit and was wondering what performance cams i could use with a turbo setup. thanks.

 

integral cams, hks, toda make cams for 1.6's, what's your goal for the power/use, and what engine management you're gonna be using?

 

Wont net you much benefit.

 

care to elaborate?

 

I smell bullshit and am willing to prove it.




Dyno proof forthcoming...

 

Exactly, just because nobody (almost) in the Miata world does it, doesn't mean they do not work.

 

Ya, but Ben bought his cams at Target!!! Cams can make a difference but it has to be integrated into the whole setup, primarily useful for moving the curve up and down in the rpm range.

Mark

 

Has anybody tried doing some work with adjustable pulleys on stock cams? Or maybe just an exhaust cam?

I would imagine there are some gains specially in the low-end by reducing overlap and compensating that with higher-lift.

 

Yes and it all works the same as any other motor, it is just most of us are to cheap and DIY oriented to splerge for dialing in cams like that.

 

Why do you need to splurge or give up DIY orientation to dial in cams? Lots of people in the Suzuki and Honda communities do it.

 

becouse to do it right you need to spend time on a dyno and that costs 100's of dollars unless you know a buddy with a backyard dyno that will let you tune for free. I doubt any of us would get very far trying to dial in a cam for max power etc, raod tunning the car as appossed to dyno tunning it. All other tunning Fuel spark etc can be done on the raod with an *** dyno esp since we can change those settings on the fly with a aftermarket ECU. I know if i throw in cams i research on the theory and set it up for the best theoretical gains and look from there. Becouse i doubt i will get the time or money to properly dyno tune them in.

 

my build will be for a mild setup. but im not sure what lift and duration works well with forced induction. i will also be using adjustable cam gears, and dyno to tune it.

 

Eliminator on .net got good results from his cams. Ultimatly i don't see this as a mod for people trying to go mild becouse well a stock or even a ported stock head and stock cams do a pretty nice job, of making power in the low to mid 300 hp range. If you aren't gonna go up there i would spend the money on a better WI system clutch, suspension etc.

 

Do it. The worst result I've seen (read about) from adjusting timing on stock cams is 7whp all the way through with no sacrifice anywhere. Makes sense that power would go up if you stop blowing boost straight through the head.

I'll be upset if I don't see 15-20 hp out of my cams and gears compared to stock.

 

Overlap isn't good for getting a turbo to spool, but some overlap is good as it helps to clean the combustion chambers of residual exhaust gases, and filing them with air and fuel instead. This extra air and fuel is more hp. You need some overlap to make good power. You need more to make power higher in the RPM range.

 

Maybe for an NA engine. Atleast in theory, boost can compensate for those 20 degrees of overlap you have on a stock 1.6. Since we have DOHC we should be taking advantage of the ability to vary intake and exhaust independently. I dont know why many people haven't done that yet since cost-wise pulleys dont cost that much. A good place to start would be retarding the exhaust cam IMO. Of course the goal would be to pick up hp in the lower rpm range.

 

Do B6T cams from the 323 gtx work?

 

If you find them, maybe. The B6T is rarer than hens teeth as far as I can tell.

 

I've got a set. Someone want to buy them.

 

B6T's are easy to find in the junkyard, just look for a Capri XR2. These cams should favor smaller turbine housings and/or wheels, and restrictive exhausts. Using an automatic Miata exhaust cam is an old GTX "upgrade" for more midrange torque. I think that'd work okay with a free flowing exhaust but I'd rather play with the B6T exhaust cam timing and just add a little bit of overlap.

Kia Sephia's and some MX-3's have a B6DE that's similar to a BP (CAS/dist is on the exhaust cam, injector bosses in the head). It might be possible to use those cams for a cam swap? Anyone measured them?

Does anyone have experience with 250* Mazdaspeed cams? Used them in a turbo engine?

Overlap let's the exhaust blow into the intake when backpressure in the exhaust manifold is greater than intake/boost pressure...