Advance Timing on a NB, anyone done it?

satanoperca · Postby **satanoperca** » Thu Apr 10, 2008 1:09 pm

Hi,

Has anyone advance the timing on a NB by modifying the CAS bracket?

My current static timing is 8 TDC and would like to advance it to 12 TDC. I run 98Ron fuel.

Did you move the bracket up?

Did it achieve any noticable differences in power?

Cheers

Benjamin

Steve Tinker · Postby **Steve Tinker** » Thu Apr 10, 2008 3:09 pm

There is mention on Miata.Net about a guy who filed his CAS bracket to give an adjustment, though Miata.Net did not recommend it.
Look under MX-5 Miata Forum Garage Section - Miata Ignition.

Advancing the Timing on a '99 Miata
This was on a US-spec car in Puerto Rico. We have no additional information regarding performance, reliability, or anything else. Miata.net does not recommend this procedure.

\"I advance the ignition to 14 degrees on my '99. It's a matter to trick the ECU. How?, Repositioning the Crankshaft Position Sensor more upward. CPS is on the right down side of the Crankshaft Pulley. First, I disconnected the CPS connector, remove the undercover, then remove the CPS bolt. Once a time I got it out of the car I proceed to enlarge the hole (bottom side) of the CPS bolt in order to get the upward reposition. Using my portable Dremer I cut off (\"bore\") about 2-2.5mm from the integrated washer in the mentioned hole. Finally, I installed back the CPS having condider the following: Air gap between Pulley Plate teeths & CPS (Spec: 0.5-1.5 mm) and tightening torque of CPS bolt is 69.5-95.4 in-lbf. Past Specs were taken from the Miata'99 Workshop Manual.

After complete the installation. I used Timing light to check my new timing and SURPRISE!: timing is now oscillating between 14-16 degrees at idle instead of the factory oscillating 9-11 degrees.\"

Rotary · Postby **Rotary** » Sat Apr 12, 2008 12:27 am

Yeah, its one of the best mods i have done so far.

Good improvement in low down midrange torque

Massive improvement to overall drivability, light throttle, take off etc.

Very easy to do, I did it similar to the above instructions(drill hole in sensor). but using calculations i worked it out to be +8 degrees advanced.

this advance runs perfect even on 91 ULP. so i might advance some more

ducktape69 · Postby **ducktape69** » Sat Apr 12, 2008 3:07 pm

seems pretty silly to me...
mazda spent a lot of time and money to UPGRADE the engine to vti.
why would you go backwards?

satanoperca · Postby **satanoperca** » Mon Apr 14, 2008 5:19 pm

Thanks for the replies.

I have gleamed much information form the miata.net site.

I do not believe my 98 model came with VVT or VTI.

I will give this mod a go and report back.

Cheers

Benjamin

SuperMazdaKart · Postby **SuperMazdaKart** » Mon Apr 14, 2008 5:42 pm

it's SV-T isn't it?

Fra66L · Postby **Fra66L** » Mon Apr 14, 2008 9:09 pm

Yep!

samx5 · Postby **samx5** » Tue Apr 06, 2010 4:38 pm

Just been looking at this for an NB8A (no VVT of course), I've been informed that you can get a part off the shelf that gives an advance to 14 deg - I'm no mechanic but I believe its the black disc that spins inside the CAS that is replaced with an aftermarket part to change the ignition to 14 BTDC......? Has anyone done this mod? It doesn't seem to need the dremel like the method described earlier in this thread & seems to be easily reversible......?

wun911 · Postby **wun911** » Tue Apr 06, 2010 5:45 pm

Would this be the same effect as buying and installing adjustable cam gears???

I have the VVT I hear some pplz on turbo miata net disabling it when they install their turbos, apparently when disabled its effectively increasing the intake timming???