Tell us about your timing cards!

[snakebit]

Inquiring minds want to know: are you running a bigger pulley; do you miss any of the top end hp; SOTP impressions; old and new dyno charts; etc., etc?

[tann3r]

Indeed! We want to hear the results and vicariously live the trills! Once I get a new clutch installed, I'll slap onthe 115mm and snag a timing card.

In the mean time lets hear how its working for you.

[Tom @ Fast Forward]

Well, I slapped on a 130mm pulley to see how well the TC works and so far, so good. With the 130 mm before, I couldn't get past 5000RPM without ping even with straight 101 octane. Now it runs right up to 7000 on 91 octan AZ gas with 15% ethanol. Off to the dyno in an hour to see how my tired old 130,000 mile stock engine handles the new found power.

[fourwhls]

Well, I slapped on a 130mm pulley to see how well the TC works and so far, so good. With the 130 mm before, I couldn't get past 5000RPM without ping even with straight 101 octane. Now it runs right up to 7000 on 91 octan AZ gas with 15% ethanol. Off to the dyno in an hour to see how my tired old 130,000 mile stock engine handles the new found power.

Any Results?

[Tom @ Fast Forward]

Of course. To an engineer, there are always results in any test. :)

Now, if you were asking if they were good results, that is up for debate. We had no problem making 7000 RPM on pump gas. We gained about 25 ft-lbs of torque peak. The bad spot was a loss of WHP up top. We appear to be making the knock sensor think there is knock from the added noise of spinning the blower at 14,000 RPM (sounds real sweet). It is either that or the 20PSI boost is blowing out the spark? In either case we have a real nice ignition oscillation and it is not from the TC.

On the fuel side, I cut way back on the fifth injector and had a perfectly flat A/F at about 11.6. I have never had a curve that flat, ever, that I can remember. I have it tuned so well that the A/F is the same in any gear even at part throttle.

So, I am tied up for the rest of this week on other projects but I will get back on it Monday and re-dyno Tuesday. It may be as simple as re-locating the knock sensor or reducing the spark plug gap from 0.032" to 0.028 or something else as simple. I took a twisty road with canyon dropoffs this afternoon so I could beat on it and see how it worked under a lot of heat. That low end torque is awesome. Then I started hearing loud knocking. But that was just my knees knocking out of shear fear from the drop offs. :driving:

[Mx5-4me]

I took a twisty road with canyon dropoffs this afternoon so I could beat on it and see how it worked under a lot of heat. That low end torque is awesome. Then I started hearing loud knocking. But that was just my knees knocking out of shear fear from the drop offs. :driving:


Sounds like a loose nut between the steering wheel and the gas pedal ...

:1eye:

[socal pat]

So Tom, can you give us a shred of data? Maybe a Torque number at least? I need something to gnaw on while I'm deciding on my next pulley size. :drool5:

[snakebit]

20 psi!:eek: I'm surprised you're not blowing the boost lines right off the PC Pros cards.

[Tom @ Fast Forward]

I need to fix the timing oscillation that I think is a confused knock sensor (?) before I can get real numbers but it had about 165Tq at 2000 RPM. Peaked at 176 but I think it would have been a little higher. It's still a blast to drive and the 200WHP number is decieving. It feels a lot faster and just runs really smooth to redline. Give me another week to play.

[ThomS]

Of course. To an engineer, there are always results in any test. :)

Now, if you were asking if they were good results, that is up for debate. We had no problem making 7000 RPM on pump gas. We gained about 25 ft-lbs of torque peak. The bad spot was a loss of WHP up top. We appear to be making the knock sensor think there is knock from the added noise of spinning the blower at 14,000 RPM (sounds real sweet). It is either that or the 20PSI boost is blowing out the spark? In either case we have a real nice ignition oscillation and it is not from the TC.

On the fuel side, I cut way back on the fifth injector and had a perfectly flat A/F at about 11.6. I have never had a curve that flat, ever, that I can remember. I have it tuned so well that the A/F is the same in any gear even at part throttle.

So, I am tied up for the rest of this week on other projects but I will get back on it Monday and re-dyno Tuesday. It may be as simple as re-locating the knock sensor or reducing the spark plug gap from 0.032" to 0.028 or something else as simple. I took a twisty road with canyon dropoffs this afternoon so I could beat on it and see how it worked under a lot of heat. That low end torque is awesome. Then I started hearing loud knocking. But that was just my knees knocking out of shear fear from the drop offs. :driving:

This may be a dumb question but here it goes.

I thought that the perfect A/F # was 14.7 ?
Isn't 11.6 a little rich ? But steady numbers would be nice.

[Kyp J]

This may be a dumb question but here it goes.

I thought that the perfect A/F # was 14.7 ?
Isn't 11.6 a little rich ? But steady numbers would be nice.

Thom

There was a thread about this in the supercharger topic. Maybe this will work:

http://www.fastforwardsuperchargers.com/forum/showthread.php?t=900

I haven't tried copying the links here before.

[mx3jmcb]

This may be a dumb question but here it goes.

I thought that the perfect A/F # was 14.7 ?
Isn't 11.6 a little rich ? But steady numbers would be nice.

You wouldn't want to have a 14.7 AF....14.7 is refered as the optimal AF for a naturally aspirated engine however FI engines need to run on thev safer side meaning with more fuel. 11.5-12.5 is usually the norm for FI engines.
With a 14.7 AF, you would blow the engine very quickly with an FI engine.

[Mark]

You wouldn't want to have a 14.7 AF....14.7 is refered as the optimal AF for a naturally aspirated engine however FI engines need to run on thev safer side meaning with more fuel. 11.5-12.5 is usually the norm for FI engines.
With a 14.7 AF, you would blow the engine very quickly with an FI engine.

All engines whether forced induction or not will richen the mixture based upon the load it sees. 14.7 is more of a steady state number that you would see when there is no load. Say cruising or at idle. I found this article a few months ago which helped my understanding:

Click here. (http://www.autospeed.com/cms/A_1595/article.html)

[snakebit]

Mark,

This line from that AutoSpeed AFR article makes no sense to me:
"However, a meter reading richer than reality is in many ways a safe meter - the tuner won't set up the car dangerously lean."
That seems backwards. A meter reading richer than reality, for ex. reading 12.5/1 instead of the real 13/1, is going to result in a motor running too lean, not too rich. The meter says 12.5/1 and the actual AFR is 13/1 - with a FFSC coldside on a 99-00 Miata, this is dangerously close to piston-melting territory.:nono: