Low end torque upgrade?

[pebbles22]

I was hoping to get some information or suggestions on how to improve the low end torque of a 1990 NA6 mx5, it currently already has a exhaust system and intake system, budget is an issue so turbo systems or superchargers isn't really an option unless its around $2k. Also i apologize if this post belongs in another section or has already been asked. thanks

[MrRevhead]

Advance your timing to 14 degrees if you haven't done so already

[Guran]

I've read that 14 degrees timing mainly benefits top end power. For mid range torque, the same source advises 18deg BTDC. Probably also need to run 98RON fuel too.

What rev range do you want more torque in? If you're driving around always below 4000rpm, you're really missing out on the best bits of an NA6. Let it go and rev to 7000rpm. The car will love you for it.

[Steampunk]

I've read that 14 degrees timing mainly benefits top end power. For mid range torque, the same source advises 18deg BTDC. Probably also need to run 98RON fuel too.

14degBTDC doesn't benefit top end, it simply doesn't affect top-end. As revs rise and engine efficiency increases, the need for advanced timing diminishes exponentially.

Although 18degBTDC will give you better low-mid range, top end will suffer considerably, hence they only recommend 14degBTDC, ie. more advance = more low-end torque at the expense of top-end.

[NitroDann]

I could build you a bolt on turbo system that would add 50% more bottom and mid range for around your budget.

I even have a tiny little turbo perfect for it sitting here.


Dann

[project.r.racing]

I coukd build you a bolt on turbo system that would add 50% more bottom and mid range for around your budget.

I even have a tiny little turbo prfect for it sitting here.


Dann

^This^

Getting low end torque out of a small capacity engine without a turbo is like getting blood from a stone. Either turbo it or live with it as is.

[Guran]

I've read that 14 degrees timing mainly benefits top end power. For mid range torque, the same source advises 18deg BTDC. Probably also need to run 98RON fuel too.

14degBTDC doesn't benefit top end, it simply doesn't affect top-end. As revs rise and engine efficiency increases, the need for advanced timing diminishes exponentially.

Although 18degBTDC will give you better low-mid range, top end will suffer considerably, hence they only recommend 14degBTDC, ie. more advance = more low-end torque at the expense of top-end.

I was paraphrasing the advice from Norman Garrett, who was a Mazda Engineer involved with the development of the MX-5.

You can get 20 percent more torque at 1000rpm by increasing your base ignition timing from the stock 10 degrees BTDC to 18 degrees BTDC. The extra low-end torque is particularly useful for drivers who like to shift under 5000rpm. This 18-degree advance setting will, however, require the use of high-octane fuel.

If you shift most of the time at 6500rpm or greater and are looking for more top-end power, advance your base timing to only 14 degrees BTDC. This is the optimal setting for maximum peak horsepower at top rpm, and it still offers a noticeable boost in low and midrange power and torque. At 14 degrees of timing, you won't also necessarily need high-octane fuel.

He quotes max power of 99.5HP with 14 degrees base timing, versus 90.7HP with stock 10 degrees base timing. A 10% boost in top end power, supported by dyno data.

I've never tried 18 degrees myself.

[Steampunk]

I was paraphrasing the advice from Norman Garrett, who was a Mazda Engineer involved with the development of the MX-5.

So was I.
There should be a diagram in there (or was it another book, the Keith Tanner or Rod's Manual one maybe?) with a graph that shows the relationship between timing, RPM, and power.
It depicts the ignition curves of 10, 14, and (I think) 18 or 20 degBTDC.

It plainly shows that 14DBTDC is the optimum advance to increase power across the board, anything above has compromises.

[manga_blue]

You mean like this:



Ths is read straight off the stock ROM in my NA8 ECU but I believe the NA6 is the same.

You can clearly see where the Mazda engineers had another complete brain fart and put a huge amount of advance in the area of mid-range / low throttle (the orange and red sectors on this map). Both top end and bottom end need more advance than Mazda allowed but you can't do this by altering static timing without increasing the likelihood of pinging in that bad mid-range section

[Steampunk]

Nah, nowhere near as fancy as that Phil.
It's a simple 2D graph that looks like this one:

Timing

But Y scale reads opposite and transposes different timing advance curve on the same graph, 10DBTC solid line, 14 dash-line, 18 dotted line

[NitroDann]

So........

Turbo?



Dann

[Apu]

I got a used T25 or a brand new TD04 for sale!

[16bit]

stop being a pussy and http://www.ebay.com.au/itm/NOS-NITROUS-OXIDE-SNIPER-SYSTEM-UNIVERSAL-EFI-4-6-CYL-35-75HP-WET-SHOT-NOS07005-/180901137955?pt=AU_Car_Parts_Accessories&hash=item2a1e8c4e23

[NitroDann]

On the right is a 2560, the one on the left is what he wants.



Dann

[M1474]

Baby turbo or ban.