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-   -   To VVT or not? (https://www.miataturbo.net/general-miata-chat-9/vvt-not-23413/)

JayL 07-10-2008 10:14 PM

To VVT or not?
 
Now that everything for my car has been fitted and will be running in the next week or so on the stock block, I need to start planning for the built motor so I can have some real fun before I get borred and sell it. My car is an 01 and I like the concept of vvt. Common sense tells me to just follow what everyone else has done and go with what is proven. But since I like things to be difficult, I was thinking maybe I could get a little more out of the engine if I do my build around it. With the hydra I can tune for it, so I'm wondering if it would be beneficial on a built motor? Anyone on here running a built motor with VVT currently?

sn95 07-11-2008 01:48 AM

I'd suggest looking at this thread:
https://www.miataturbo.net/forum/showthread.php?t=23228

Note that Y8s has done some dyno testing on VVT showing low end and top end benefits. At the end of the day, the real benefit of VVT is going to depend upon a few key variables:

1. Are you going to get an aftermarket/custom VVT intake cam?
2. Are you going to get an aftermarket/custom exhaust cam?
3. Does your aftermarket ECU support full control of the stock VVT system?

If you really want to maximize the VVT benefit on a "built motor" you are going to have to model (or have a custom cam grinder model) the airflow of your proposed engine combination. This starts to get a bit complicated on a FI motor because you need to supply blower stats in addition to all the other engine stats (induction system CFM flow, bore/stroke, rod ratio, static compression, intake/exhaust valve sizes, intake/exhaust port CFM flow from
.100 to .600, exhaust type, target operating RPM range (1-7K stocker vs. 4K-8K race engine) etc.

I'd suggest doing some software modeling (several good engine sym packages available) to get a better handle before you start spending any money.

JayL 07-13-2008 03:13 AM

Quote:

Originally Posted by sn95 (Post 281776)
I'd suggest looking at this thread:
https://www.miataturbo.net/forum/showthread.php?t=23228

Note that Y8s has done some dyno testing on VVT showing low end and top end benefits. At the end of the day, the real benefit of VVT is going to depend upon a few key variables:

1. Are you going to get an aftermarket/custom VVT intake cam?
2. Are you going to get an aftermarket/custom exhaust cam?
3. Does your aftermarket ECU support full control of the stock VVT system?

I've been following that link, can't wait to more people start going in this direction. I'm looking to take this in a different direction. So for now, I'm actually looking for someone that's already got a built motor and running the VVT. As for the variables you mentioned, here they are:
1 & 2 are undecided at this point because I don't really know if it will be worth it to get custom cams made to my specs. I want the power, but the cost involved most likely won't justify the return considering this will only be a temporary setup for a year or so.
3. I run a Hydra, so yes I have full control of the stock VVt system.

I guess what I'm asking is this: has anyone done a 01 head with VVT in a high horsepower application?

mx03tb 07-13-2008 05:24 AM

i'm going to be running a built 03 vvt head with only stock cams and a fully built bottom end...for high horse power....in the next week gotta put everything together...


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