1985 Monte Carlo SS known as Barney

[SSLance]

Greg, at WOT my engine's sweet spot is 32* and I currently have my distributor locked out at 32*. I can however retard the timing either by set RPM or vacuum with my ignition box. I currently have it retarding the timing at high load, low RPM instances with the MAP sensor and boost retard function to prevent pinging when driving on the street.

These engines will idle cleaner and cooler with 37-40* of timing and cruise timing (just off idle with a light load) also likes some extra timing. The way to accomplish that with my setup is to lock the distributor in well advanced (like 45*) and retard the timing via either RPM Run retard or Boost retard with vacuum signals. Doing this will help (a bit) at idle and heavy load, no vacuum, low RPM instances...but do nothing for WOT high RPM runs.

This is one of those street car vs race car battles that I constantly find myself in. Race car won this round, even though it still drives pretty dang good on the street too.

[Ron Sutton]

Originally Posted by GregWeld

Just my opinion - for what it's worth....


I've NEVER known a small block Chevy that ran with 45* advance.... and the more efficient the heads are - the LESS timing they require.

I've taken many EFI tuning classes - including those where the engine being tuned is on a dyno. It was demonstrated to us that FUEL RATIOS were relatively unimportant... affecting very little horsepower on the dyno from pig fat to too lean. What WAS important was as little as 2* of timing off optimal. The timing could affect as much as 40HP with just the slightest change. Remembering that horsepower is nothing more than a mathematical equation based off RPM and TORQUE... the torque is critically important to making a horsepower number.

Back in the day - during my drag racing years. We'd make a full throttle run - then pull the plugs (we used tow vehicles as I ran D/Gas). We'd then compare the MILES PER HOUR -- and read the plug strap. With the right timing - the miles per hour would improve - and the plug strap would change color right in the middle of the curve. That was a bingo. Now days we need a dyno to find this critical event.

Yup, Yup !

The more efficient the engine, the less timing it needs. I've had very efficient small blocks that made the most power with 32°. I've also had very in-efficient (but still 1100+ HP) mountain motors that needed 44° timing for optimum power.

And what Greg said ... 1°-2° off can be a big deal.

[fleetus macmullitz]

Good tech talk Lance, Greg and Dr. S. Sauce.

[miltmilton]

Lance,

Will you be in Mineral Wells, TX in May for the SCCA CAM Challenge?

milt

[SSLance]

I was finally able to secure an entry to the Midwest Muscle Car event in Putnam, IN this year, an event that I've missed out on the last couple of years...then the SCCA announces that the Texas CAM event is the same weekend.

I'll be in Putnam...

[SSLance]

I decided that since my engine upgrade is basically finished and I had a bit of time and money left over...that I'd tackle some left over suspension projects.

My first chore was to corner weigh and balance the car again. I have not done this since before all of the interior changes last year and the aluminum heads this year. First step was to disconnect the sway bars front and rear. After that set tire pressures to race trim, remove spare tire and it was ready to weigh...fuel tank was completely full. Basically the car shed about 80 pounds with the changes above, but the corner balance\cross weights stayed in the range they needed so I didn't need to make any adjustments to the springs.

Here is the car in race trim, no driver.



With driver


and cross...



Car still has 57% on the front just a little bit less than before is all. Cross is within a half a point of the total right weight which is where Ron likes to see the cross on a left heavy car like mine. Right front could use 10 more pounds or so but that isn't enough to mess with making changes in our eyes. Overall I'm happy with it, really good to see it under 3500#s now.

So while it was on the level blocks, I decided to recheck the alignment.



Apparently my mechanic forgot to set the toe last year after making some rear ride height and caster changes...so I raced all year last year with a 1/4" toe in. Good news is, with alignment set at 1/8" out...now my steering wheel is straight again.

Then I removed the F41 Jounce bars and Gran Prix bars along with the already removed rear sway bar...in preparation for some new parts on their way from UMI.

The Jounce and Gran prix bars plus hardware weighed in at 6.76#, Ramey says UMI's new front brace weighs 9#s. I'm thinking the extra 3 pounds will be worth it.



I'll weigh the new rear sway bar against the old once it gets here and share as well.

That's it for this weekend...unless I get froggy and decide to clean the wheels up, they kinda need it.

[Tomswheels]

Sweet Lance, excited to see how she does on track!

[SSLance]

Last night I installed a third chassis mounted Pro-Touring style rear sway bar on my car. The first one I never even finished with the install because it would not clear the lower control arms I had on the car at the time (the company graciously accepted the return). The second one required me to heavily modify the axle mounts to get it to clear my 9” housing and also took quite a bit of reconfiguring to get the end links to clear my tail pipes and lower control arms. I took it back off right away after testing showed it to be much too stiff for my application.

For over a year now I have been asking Ramey at UMI Performance to build a chassis mounted rear sway bar of the right size to work for how I use my car. They did just that and I finally ordered one of their ¾” solid rear sway bar kits for a G-Body and installed it last night. I’m not kidding when I say it took me less than hour start to finish for the install. The hardware UMI provided with the kit is top notch and everything fit just perfect on the first attempt. For example, the brackets used to attach the end links to the chassis, the other 2 bars used a single bolt to hold the brackets to the frame… the UMI kit uses not only 2 bolts but also a reinforcement plate behind the chassis to secure the bracket to the frame.



And the end links are short enough to allow the bar to sit at a decent angle even with the lowered stance my car sits at.



The bar clears the axle housing with zero issues and sits just about as perfect as it can.





Overall, I’m impressed with the build quality and more importantly the design that went into this product. I can’t wait to see how it performs on the street and on the track. My first autocross test n tune is April 9th. I’ll have my new UMI G-Body front chassis brace installed by then as well.

[SSLance]

Put my UMI Performance Inc. front chassis brace on this morning, another fine piece from UMI. Bolted right up, fits like it should and looks to be beefy as heck.





Clears the massive MuscleBar easily...




Just one week away from putting all these new parts to the real test. All car needs now is a good cleaning and it's ready to race.

[Donutboy97]

that does look good... can't wait to see how it performs!!