Olds Achieva day at the Test & Tune

[Robert Swartz]

Got to spend a rare Saturday at the local track. They've started a once a month index race series for the fast bracket cars (not well attended, I might add). In addition for a small price they opened the track up to Test and Tune for anyone interested.

We decided to take advantage of this to both try different driving methods and hot lap the car to see if we could back up runs.

Art Leong, after running the car this day, your statement on the computer controling what you try to do to the car is correct. For us this day, it mainly concerned the transmission. The car has a automatic, 4 speed OD. It has a built in 1-2 eshift. It never got to 3rd, when manually shifted.

We had really good weather, for July, 70's-80's low humidity. We developed a new problem. For the first time we've run the car, it spun the tires. I suspect that being more a consequence of what the track had done for this race. They had moved the water box forward. This car at present cannot do a burnout, we tried. I set the parking brake, it just pushed out of the water and drug the back tires through. Still trying to figure out how you guys with FWD do a burnout? For this car, my suspicion is, we still had some residue on the front tires. Next time out, the car will have a set of 22" tall DR's. They will be 2 or so inches shorter than the current street tires.

ET wise, the car has pretty much settled into a pattern. The fastest time of the day being an 11.48. The majority of the runs being in the 11.50ish range. We were hotlapping the car, noticed that engine temperature would progessively slow the car down. I made a 4 pass stint, noted that each pass, the car would slow a few hundredths each pass. First pass would be an 11.5x, by pass 4 would be 11.6x. As others have stated, temperature definitely affects these smaller engines.

Overall, a productive day in that the car did what I had anticipated it would do. I'm at a crossroads with this car. As it sets, it can be a pretty consistant "slow" bracket car. To be anything more, I will need to get serious about what I do. Meaning first, I need a real weight assessment. I dry weighed the car with about 3/8's a tank of gas at a truck stop. the slip says 2900 lbs. We suspect they rounded the weight off. In the end, I know for the class we're looking to put the car in, it's at a minimum, 200 lbs heavy.

I guess a question to pose. At what point do you begin to question if a car is worth the further investment of money and time.

[nickh]

Robert is there room for you to drive around the water box and not get water on the front tires?

[Dennis P Chapman]

Robert when I do my burnout I roll threw the water and just hit it this works good for me. Some guys may use line lock to the rear brakes.

[art leong]

I do what I call a funnycar burnout. Roll through the water with the front tires. To where the surface is wet , but not where you will spray water on your inner fenders.
I now start in second gear but for years I was using first gear. As soon as the tires come loose I throw third gear. And just roll forward. The tires will smoke some, but not a lot.
As soon as the tires hook you have to back off the throttle. This is critical in my case for transmission life.
Just make sure you wait till the starting line crew, and everyone else is clear before you start. I've had them motioning to me to start my burnout while they are still mopping up the starting line. I just wait.

[Ed Wright]

Robert, if you think the ECU is learning to undo your changes you can jumper the ECM (or PCM) Batt fuse to the powered side of the ECM (or PCM) Ign fuse. That way every time you turn it off any learning will be lost. I think your mistaken about that happening, but that would take care of that if it is.

Slowing like that as it heats up is normal for those.

[Robert Swartz]

Originally Posted by Ed Wright

Robert, if you think the ECU is learning to undo your changes you can jumper the ECM (or PCM) Batt fuse to the powered side of the ECM (or PCM) Ign fuse. That way every time you turn it off any learning will be lost. I think your mistaken about that happening, but that would take care of that if it is.

Slowing like that as it heats up is normal for those.

Ed,

At present, we don't have a way to tune the car. The ECM still has complete control. What I ran into, we were attempting to vary the shift points. It would shift at 6200 rpm in spite of what we did.

That's something I don't have is an ability to make tuning changes to the ECM. I don't know of any chips for these cars. An avenue I haven't explored deeply, yet.

Thanks for the burnout tips, guys. Until I get the DR's on it, that's really not an issue. Does give me something to work on.

[art leong]

Originally Posted by Robert Swartz

Ed,

At present, we don't have a way to tune the car. The ECM still has complete control. What I ran into, we were attempting to vary the shift points. It would shift at 6200 rpm in spite of what we did.

That's something I don't have is an ability to make tuning changes to the ECM. I don't know of any chips for these cars. An avenue I haven't explored deeply, yet.

Thanks for the burnout tips, guys. Until I get the DR's on it, that's really not an issue. Does give me something to work on.

I wouldn't go for the DR's. I have never run them. But know a lot that have. And mostly it was a waste of money. Unless rules make you run DR's Slicks are a whole lot better.

[Tod Lane]

A couple thoughts Bob.
Even with the water moved toward the starting line the actual start line prep was the same as always.
The air was noticably better,cooler and less humid.
The passes I made in the car I never tried a burn out but I did manage a couple lets call them dry hops for the lack of a better term, it still spun launching off dead idle, pushing it to 1200, or completely loading it to maybe2300.
It felt like it spun for20-30 feet , the more launch rpm the longer it seemed to spin.
I think the better air=more hp which caused the wheel spin and netted slower times. Hot laps probably contributed as well

[Ed Wright]

Is the ECM case sheet metal or cast alum?

[Robert Swartz]

Originally Posted by Ed Wright

Is the ECM case sheet metal or cast alum?

Ed, it's the sheet metal case.

Art, I'm using the DR's for now, because of wheel size limitation. All the good low profile slicks are in 13 inch sizes. With this car, they started building them with the larger front brakes, 13" wheels don't fit without converting to earlier brakes. Also, the 120k engine doesn't make a ton of hp. With this transmission, don't know how cost effective making a set of lower gears would be at present. If we keep the car. Start working toward making some real power. This will become a necessisity. The tires are an easy change.

The next option, in my playbook, is a header. A guy in neighboring Ohio makes a nice one. Other than a way to tune it, as well as start to look at how to work with the suspension. I want to stiffen the rear. Haven't really figured out what I can do converterwise, yet. After that, it's time to go into the motor.