Organized Drag Racing and AutocrossDrag racing and autocross discussions and questions. Techniques, tips, suggestions, and "what will I run?" questions.
Welcome to ThirdGen.org!
Welcome to ThirdGen.org.
You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join the ThirdGen.org community today!
First time at the track in 2006 with the new 540 for a T&T night. It's nice to finally be able to update my sig.
I only made one pass tonight and it wasn't pretty. I have/had an oil leak at the back of the intake which I hope I've fixed for tomorrow. The engine runs good and I "know" I easily got the front wheels off the ground when I launched.
Down side of the first pass of the year and it was a solo T&T run.
Didn't turn on the playback tach or at least I don't think I did.
Asleep at the tree and didn't let the transbrake button go until almost at the third yellow light. .937 reaction time. .000 is perfect.
I think I shifted when the shift light came on at 6800.
I could smell tire smoke down near the end of the track. Shut everything down after cross the finish line and coasted down to the end and off to the return road.
Raising my ladder bars up one hole moved the axle back slightly and the driver side rear tire caught part of the inside of the outer fender. It make a cut down the slick. It's not into the cords and I want to make some passes tomorrow. I'll probably buy a new tire if it at least gets me through the day tomorrow.
The oil leak is still there and there's a slight coolant leak on the overflow hose at the rad. I fired the car back up and picked up my time slip. An ugly 9 second pass Temperature never got above 180* and I staged the car around 140*
Came back to the pits, took off the slick and hammered the inner fender out of the way. That fixed that problem. Updated the log book and did some other routine stuff then loaded the car onto the trailer to bring home for some repairs/changes.
Changed back to my old valve covers so I could use the header evac system since the vacuum pump system I have still doesn't seem to pull enough air. I redesigned it now so the driver side evac goes through the vacuum pump first then out to the header. That way I can still use the vacuum pump to pull the moisture out of the crankcase between rounds. After doing the swap and using the vacuum pump, I could hear the leak at the rear of the intake. Some grey silicone on my finger was able to find and stop the leak. It has overnight to set up. I may have to pull the intake and reseal it later.
Other than the oil leak/excess crankcase pressure which are probably related, and the tire rubbing, the car ran good. The noisy gear drive is annoying even in a race car but the new race mufflers sure are nice. I may change back to a timing chain after this weekend. With the hood closed and the 2 filters sticking out the top, you'd almost say it sounds like I have a blower under the hood.
Still needs more T&T time. I'm still predicting at least a 9.6 at 135 mph this year at altitude. Tonight's air was fantastic. One thing I wasn't able to do today was get the car across a scale. I'm still guessing at a 2975 race weight. From what I've done over the winter, a total weight closer to 3050 is probably what it is now. A heavier weight will bump up my calculated HP numbers. As long as the car is still driveable after tomorrows racing, I'll get it weighed.
This ad is not displayed to registered members. Register your free account today and become a member on ThirdGen!
__________________
87 IROC-Z
All engine, no power adders! Bests: 9.348@144.71
Last edited by Stephen 87 IROC; 05-14-2006 at 01:50 AM.
Sponsored Links
Registered users do not see this ad. Click here to register for free!
Stephen, congrats on those numbers!
I watched the pass from the stands and indeed you did lift the front end off the ground(VERY nice).Your tires smoked for most of the track
Car sounds very strong as well.Your prediction of 9.6 and 130's will be easily achieved.
Beautiful numbers for the first time out.
Was really nice to meet you and the car
~Christine~
Actually the mph is low for the ET. The engine sounds like it's running fat on the top end. I need more jets so I can jet down 2 carbs. I only have enough jets to do one carb.
I got 4 passes in today with a second round loss. I screwed up big time on the tree. Other than that, the day went uneventful. I did everything right including turning on the replay tach. My screwup in round 2 was with setting the transbrake. I don't know what happened. I think I let go of the brake pedel before the transbrake set and rolled ahead slightly. I didn't red light but it screwed up my concentration. I never go a chance to get up on the converter and the lights were coming down before I let the transbrake button go. Oh well. I'm just happy it wasn't a first round loss. My first round win was with a .037 light against a .027 light. My last T&T pass had a -.008
The car set another personal best in the morning then slowed down by afternoon. The conditions didn't change that much except for a slight headwind so it might be some unforseen problem slowing me down. I'm going to check a few things out before the next race. MPH was reasonably consistant starting off with a 132.42 but slowed down to a 129.68 but that run was the one I screwed up and I'd have to call it a garbage run. Slowest run before that was 130.96 mph.
I have 3 weeks now to do any repairs/changes. There's a few things I need to fix or adjust. So far there has been no tuning on this engine. Can I run faster if I play with jetting or timing, probably but I just don't have the track time to do it. I would like to pick up a little more to get off the 9.9 - 10.0 range. Consistant 9.7 to 9.8's would be nice. That way I can leave the 9 on my windows.
It sure is fun going down the track in a fast car again. The car launches hard and runs straight. Last year the car always wanted to pull to the right after a launch.
I was too tired to take the car across the scales today so I still don't know what the 2006 race weight is.
Sounds like the car is going to be awesome. It would be cool if someone could get some video for you so we could all see. Good Luck in getting the kinks out.
__________________ 82 Camaro, 383SBC, Eagle Competition Rotating Assembly 12.75:1, Comp solid roller, .631, .630 lift, Dart Pro1 215 Alum. Heads, Harland Sharp 1.65 Rockers, 825 Demon Carb, CSI Elec. Water Pump, SPAL Dual Fans, Hooker SuperComp, 5000 Stall, TH350, B&M, 12Bolt 4:33, Full Spool, SFC, Ladder Bars, Lakewood Fronts, Comp. Eng. Adj. Rear Shocks, 15" 28x10.5 MT's ET Drags. Best 60' 1.42 Best Run 10.811 at 125.63
I'd love to have some footage of my car going down the track.
Part one of my modifications are done. I yanked out the noisy timing gear drive tonight and reinstalled a chain system. It was too late to fire the car up to hear how it sounds now.
Actually the mph is low for the ET. The engine sounds like it's running fat on the top end. I need more jets so I can jet down 2 carbs. I only have enough jets to do one carb.
I meant the same thing - the ET is low (numerically) for the MPH. The car is efficient and using its power effectively.
Well based on the power to weight ratio and an unknown weight since I'm still using last year's weight, my best run gave me corrected 676.06 RWHP from the ET but only 594.53 from the MPH. If the car is heavier than last year then the corrected HP is higher.
Bumping the MPH HP up to equal the ET means it should be running 138 MPH at 9.8 seconds instead of only 132
No headache at all in tuning two carbs. Make everything identical and make sure the linkage is operating both carbs exactly the same. A good linkage kit is very tunable to make sure everything is equal.
The only downside is in fine tuning. I square jet my carbs so a jet change needs 8 jets the same for 2 carbs. When tuning on gas, you change jets 2 sizes at a time. On alcohol you change them 4 sizes at a time. I only need half as many jets but twice as many of the sizes I need.
Normally once it's set up on alcohol, you don't need to change anything. Alcohol doesn't change much from weather conditions like gasoline does. Figure out what jets you need for the day then don't touch them all day.
Instead of a dominator, I'd rather have an Enderle injection system or two Flying toilets on the tunnel ram. Injected alcohol is the way to go.
I think my low MPH numbers is from running too rich. About the 1000' mark you can hear the fuel igniting in the headers.
I was doing some modifications tonight. I decided to pull the float bowls off and jet the carbs down. The last metering block I pulled off had something stuck in one of the jets. Not sure what it was. I might have been some dried out sediment in the fuel system from over the winter. Not completely plugged but still a restriction. Now that all 8 jets are flowing to their max, I should be making a bit more power. I haven't pulled the plugs over those 2 cylinders yet to have a look at them. Nice thing about a tunnel ram is that the fuel mixture should balance itself out to all the cylinders.
Great Job!
Glad to hear its running well.
As for the jet being plugged, Thought you said it was
too rich already?
I need to get a transbrake soon this year, I also think I am running
a little to rich with 100 jets in all 4 corners and twin power valves.
But having same problem as you, need track time..
Would like to check some plugs next time after a wot pass.
Wedding this weekend,streesed out bride to deal with...
From the sounds of exhaust poping at the top end, it sounded like fuel igniting in the exhaust under WOT. That's usually an indication of running too rich. Because I was working on figuring out other stuff, I never had a chance to look at my pyrometer near the top end to see what the exhaust temperature was. Somewhere around 1200 - 1300* would be best.
With the #100 jets and the hole drilled above the jets, it's roughly equal to running a #185 jet. Typical alky carb jetting is in the 160 - 180 range. When I bought a bunch of jets after the weekend, I couldn't get any #96 so I picked up some #95, #92, and #88 so I now have 8 each of those. As I mentioned above, you change alcohol jetting 4 jet sizes at a time. I now have 95's in all the metering blocks so I should be jetted down to 180 now. Probably still rich and at our high altitude I should go down even more. It doesn't hurt the engine to be too rich but too lean is dangerous.
A power valve is equal to about 8 jet sizes. I run plugs in all my metering blocks.
I wouldn't have a problem checking my spark plugs. As soon as I cross the finish line, the tranny is popped into neutral and the engine is killed. I coast all the way down to the end and still have enough momentum to come around to the backside of the return road. In a way it's nice to share the road course with the dragstrip. Nice gentle turns at the far end.
Temperature never got above 180* and I staged the car around 140*
maybe someday my little motor will grant me with a pass that will let me get a tire in the air! 
