I was watching "old man's garage" on YouTube, I noticed he only has the factory seat belts in that 79 Malibu, with 6 point roll bar and it runs deep in the 10's. I know he races at a lot of different tracks but this particular day was at Norwalk and National Trails, which both used to host National Events so I would assume they follow the NHRA rules for tech.
Those guys are little more than no prep/street racers, he put the bars in for the drag and drive activities where they actually tech the cars.
I got some new boots for the back, and wheels too. 15x8 wheels with 3.5 back spacing, and 255/60R15 drag radials. The wheels are cheezy cast "modular" with the fake rivets around the outer center, so they were cheep.
Just curious, with the new wheels and tires, is the speedometer still accurate or close to accurate! Inquiring minds want to know!
oh, it'll be off a bit with them. But I don't plan on putting a lot of street miles on them, they wear out fast and cost a lot!
I took the line lock out of the Vette, and put it in Cheep. And had to do a little test burnout to make sure it was working. Then of course, get it warmed up and see how the new tires grip on the street. Pretty well, actually. I might have got some gopro video, I'll post that too if it works. Still working on it.
a rather half-hearted merge, but it was fun. If it was turning 5000 rpm at the end in high gear with 3.73 gears and 26" tall tires, I might have been going fast? or the converter slips a lot? it dropped down to 3800 pretty quick after I let off. That's not nearly as fast. Or I was on the brakes?
Do you need bigger injectors? Fuel pressure is 52. I thought it might be higher around 60. 4 lbs boost , is that what your looking for? I figured it would be around 8 to 10. I'm still learning all this myself.
The numbers shown on the left are not the actual data from the part of the log that you are looking at, that's at idle, note the RPM is 928, and boost is -4.0, which is vacuum. When it's under boost, fuel pressure goes up to around 60. If I were to move the cursor to where the action is, you can see what's going on with those numbers. The cursor is the white crosshair. also note that I'm only at about 75% throttle...
Oh...injector duty cycle, tells you if you need more injector. They're way too big, actually. The duty cycle shows in this one, they're only open a third of the time!
Creature comforts...I installed the "screen" that plays android auto, so I can do navigation/music from my phone, without breaking all those new laws. And the cup holder, with the slot for the phone to sit in. There's a late night race in Tucson tonight, it's the younger crowd money race, but they say they'll allow TnT runs between rounds or something. So I'll see what happens. Might be there till 3, who knows. But again, I'm chickening out and hauling it up on the stretcher.
Jim, do you have a way to log computer seen conditions (temp, baro)? I realize you don't have to do jet and timing changes, but it might help set dial-ins for future trips.
I should but I don't. Although the computer does log baro and mat, so I can use that to get close. Anyways, fighting the rev limiter again. Talked to the guy in the next pit, he told me what I was doing wrong. I wanted High limit only. Will try again. Right lane
The next thing I need to work on is 60 ft times. That means getting it to build boost while staging. So I get to learn about the two step rev limiter .
I did a little more research, seems that NHRA allows +/- 10% tolerance on wall thickness on the tubing. And still have not found any mention of required thickness after bending. So it seems to me that you probably won't get the answer you want to hear.
One thing I’ve found after installing a basic 5-point bar is welding the rear bars to the main hoop. If you’ve tried to get a nice tight fit hugging the roof line there’s no way to get a complete 360 weld. They do check for that I’ve found and may ask you to weld in triangular plates the same thickness as the roll tubing to strengthen the whole structure.
To fully weld the top, a common practice is to drop the main hoop through holes cut in the floor, this does require some creative juggling and getting the rear bars fitted and premarked with location lines.
I explored that idea but the way my frame and floor pan is constructed plus the rear bars passing through the parcel shelf opening it would have been easier to cut the roof off. I think the NHRA rules state they want 75% of circumference of the tube to be welded. I’m pretty close.
That's something that I had heard for years too, but reading the rules, they don't mention it... As you probably know, tech inspections at local tracks of cars that are relatively slow, never seem to include more than a glance at the roll bar/cage. I think it also has to do with the car looking in general like it was built to meet the rules. Some cars look like crap in that regard, I try to always make sure the stuff that I know needs to be done, is done. Solid battery hold down, throttle return spring, lug nuts/studs, that kind of stuff, if they see it, they don't seem to worry too much about the rest. I really do appreciate your concern.
One thing tech checks for 100% of the time at both tracks I race at are expire dates on belts and helmet.
The Jalopy Journal
