frenchyd said:In reply to rslifkin :
The Turbo 400 transmission is there a smaller torque converter with a higher stall speed that just bolts on?
Depending on the engine, there are likely a ton of off the shelf choices for that trans. Worst case, there are converter shops that could put something together.
If half the energy was put into building the car than talking about theoretical stuff you might do with the car then the car would be done by now.
Stampie (FS) said:If half the energy was put into building the car than talking about theoretical stuff you might do with the car then the car would be done by now.
But he asked a short, concise general question, and had trouble getting an answer... mostly a bunch of lip, or people that apparently could not understand the simplicity of the question.
I don’t mind giving him E36 M3 when he is playing games - either intentionally or not, but don’t be a dick when he seems to be actually trying!
In reply to 03Panther :
Counterpoint ... he hasn't done any homework to even see what kind of times he should expect with his combo. Yes valid new to drag racing question but he's "building" a road race car that he's going to autocross and drag just to see. When the 75 XJS was tested by Car and Driver they didn't wonder about shocks and springs when they did the 1/4 mile. Build what you want to build then see how it does. Ok Frenchy you're going to build an XJS right? I remember you claiming they could be stripped down to some amazing low weight. What can you build your car to? I also remember amazing HP claims using factory parts. What can you build your engine to? Let's run the numbers and see what you can do in theory. I expect the Nelson's to look at shocks and weight transfers and maybe changing between autocross and drags. I don't expect a first timer to the Challenge to do so.
Stampie (FS) said:If half the energy was put into building the car than talking about theoretical stuff you might do with the car then the car would be done by now.
You're not new here, so you should know this is understood 
rslifkin said:frenchyd said:In reply to rslifkin :
The Turbo 400 transmission is there a smaller torque converter with a higher stall speed that just bolts on?
Depending on the engine, there are likely a ton of off the shelf choices for that trans. Worst case, there are converter shops that could put something together.
But challenge rules limit the budget. If I can junkyard a different torque converter we may be talking $15 but a speed shop will get a lot more. After all I've got the whole GM line up to harvest parts from.
Stampie (FS) said:If half the energy was put into building the car than talking about theoretical stuff you might do with the car then the car would be done by now.
So asking a legitimate question when I have a spare moment is against your rules now? Stampie. If you don't know or have any helpful advice, Then what are you doing?
Stampie (FS) said:In reply to 03Panther :
Counterpoint ... he hasn't done any homework to even see what kind of times he should expect with his combo. Yes valid new to drag racing question but he's "building" a road race car that he's going to autocross and drag just to see. When the 75 XJS was tested by Car and Driver they didn't wonder about shocks and springs when they did the 1/4 mile. Build what you want to build then see how it does. Ok Frenchy you're going to build an XJS right? I remember you claiming they could be stripped down to some amazing low weight. What can you build your car to? I also remember amazing HP claims using factory parts. What can you build your engine to? Let's run the numbers and see what you can do in theory. I expect the Nelson's to look at shocks and weight transfers and maybe changing between autocross and drags. I don't expect a first timer to the Challenge to do so.
Don't you think there might be a lot of difference between a factory fresh luxury car and a 45 year old $500 junker? My car weighs 4656 pounds according to my Haynes manual. The typical race ready XJS is around 3000 pounds. I'd like to get it below that. 2700 pounds is possible.
As for first time? I've been racing since 1962. Since then I've been building and modifying cars to go racing. Please don't expect me to show up in some bone stock thing. I may be budget restricted but I'm not creative restricted.
Stampie you do bring up an interesting question. How to treat dyno time? Is the value of that added to the budget or is it free?
I used to have a "free" dyno on the hill next to my old garage. It was a steep hill long enough for me to measure time with a stop watch. I'd try various turning points and run it up the hill faster =more power. I suppose I could have done the math to figure out what horsepower I had.
Rodan said:Are you running single passes for time, or actually racing against the other car?
A quick reaction time will often win a close drag race, but it has ZERO effect on the elapsed time of the run. Reaction time is a measurement of how well you time the car's start (when the wheels break the timing light beam) to the green light. Hint: if you wait for the green light, you're already too late. If you're just running a pass for time, you can forget about reaction time.
60 foot time is all about how hard the car launches, which means it's all about traction. Get the max amount of power to the drive wheels and keep it there.
I'm still grumbly that they rejiggered the clocks to make the .500 (or .400, depending on tree) reaction time "assumed". Now if you say you cut a .500 light, it sounds like you were asleep at the wheel
frenchyd said:
Stampie you do bring up an interesting question. How to treat dyno time? Is the value of that added to the budget or is it free?
I used to have a "free" dyno on the hill next to my old garage. It was a steep hill long enough for me to measure time with a stop watch. I'd try various turning points and run it up the hill faster =more power. I suppose I could have done the math to figure out what horsepower I had.
Ok so you haven't even read the rules.
In reply to Pete. (l33t FS) :
?
I understand in drag racing you leave as the last yellow light Starts to go out. Really experienced drag racers anticipate even that.
Now are you saying that has changed?
I drag raced exactly one time. One pass. Early 70's I was selling Honda Civics and took one to North. Star drag strip. I pulled in line. Paid my $15 they assigned me to some class and asked me if I wanted to race for time or to trophy. I didn't know better so I said trophy. Lined up spun the front tires in the water until they started bouncing. And pulled up to the lights. I went when the light went out drove down the strip shifting at redline and pulled off after crossing the line and stopped at the little shack they handed me a little plastic trophy and told me I'd set the record for the class and I was done for the evening. I tried to give it back so I could keep running but I guess you can't change your mind.
Stampie (FS) said:frenchyd said:Stampie you do bring up an interesting question. How to treat dyno time? Is the value of that added to the budget or is it free?
I used to have a "free" dyno on the hill next to my old garage. It was a steep hill long enough for me to measure time with a stop watch. I'd try various turning points and run it up the hill faster =more power. I suppose I could have done the math to figure out what horsepower I had.Ok so you haven't even read the rules.
Thank you Stampie.
In reply to Stampie (FS) :
Counterpoint is true. But he did the right thing in starting his own thread to ask a question without being an ass. Let’s stick to beating him up when he is being an ass, and encourage good behavior !
frenchyd said:In reply to Pete. (l33t FS) :
?
I understand in drag racing you leave as the last yellow light Starts to go out. Really experienced drag racers anticipate even that.
Now are you saying that has changed?
On a normal tree, you have the two staging lights. You have to pull forward ("stage") enough to for your tires to break the second start beam and light the second light to show that you are ready. Then the three amber lights count down in half second intervals. You leave "on the last amber" because it takes time for your brain to send the signal down to your legs (or fingers, if you have a transbrake).
Now, there is roughly an eight inch amount of rollout before your front tires clear the second timing beam. It used to be that if you cleared the beam within .500 second of the green, you'd redlight. So a perfect reaction time was .500 seconds. The run is still timed from the point your tires cleared the beam, you can sit there for five seconds trying to build boost (common Grand National tactic 20 years ago) before you leave and it won't count against your time. Your reaction time will be really bad, however, and you just gave your opponent a 5 second head start because the race is won by who crosses the finish line first, not who had the quickest time.
A few years ago, they changed the way they tell reaction time. Now that .500 is assumed, and the reaction time calculation starts from when you are allowed to have cleared the beam, not from when the light went green.
(pete trick: I always, ALWAYS shallow stage, because that eight inch head start is worth a tenth in a 14-15 second car)
BItD they used to run a Vega converter to increase the stall in a TH350/400. It was a really small diameter (9"?) and would stall out pretty high compared to the larger diameter V8 converters. But the converter stall RpM is also based on quite a few other things, including torque, vehicle weight, gearing, and the efficiency of the converter the rest of the way down the track is an issue, as well (especially through the traps) and you can lose quite a bit of power to the tires at the big end with an inefficient converter.
Also, a high stall can be detrimental on the autocross unless you expect to above stall RpM range through the run. I've thought about this quite a bit with bench building a car for the Challenge, and if I wanted to try to be in the sub-12s in the quarter while still being competitive in the autocross, I would want to find a cheap way to run a manual trans. Of course, the lighter you are able to make your vehicle the easier it will be to run the numbers with less hardware.
90/10 shocks aren't really needed for automatics- they are usually for keeping the front end up between shifts with a manual trans. If you are running an automatic and want transfer, a worn out pair of shocks works just as well (but this is completely useless otherwise, so you had better be good at swapping shocks with real ones between events; I don't remember whether drags were first or not, but due to weather, the schedule might be subject to change anyway) Some have messed with used Rancho 9000 adjustable shocks for dual purpose (drag and street, not the Challenge, AFAIK), but you would have to spend some quality time with a shock catalog to figure out what you could adapt to your build.
My take? If I were in your shoes, I would build on your strengths (handing, engine build for your specific application for usable Hp), and minimize your weaknesses (quarter mile ET/drag race suspension) And then work to optimize your launch technique with what you have with your handling setup. Once you've got your launch as good as you think you can get, figure out what you can tweak without hurting your handling much. You should already know how to build for acceleration on straightaways, so your main need is the launch. The first 60' is where you can improve 1/4 mile times the most.
Thank you Pete. I obviously know next to nothing about drag racing.
Well hopefully someone with more experience will step up and make a pass or two.
I can't see me at 73 setting any impressive times.
03Panther said:In reply to Stampie (FS) :
Counterpoint is true. But he did the right thing in starting his own thread to ask a question without being an ass. Let’s stick to beating him up when he is being an ass, and encourage good behavior !
Good Frenchy ... good Frenchy. That better?
In reply to Cooter :
Here is my tentative budget for the Challenge. $500 car and I get to sell parts of it equal to 1/2 of my purchase so net $250. ( actually probable retail value many times this )
1984 Jaguar XJS $250
Two T4 turbo chargers $220.
Connection tubes etc $345.
Regrind stock camshafts $245
Gasket set $87
12 used injectors $35
Grind valves $240
Ethanol sensor $20
fiberglass for hood, trunk lid, and door skins $250
That should be about $1700.
Weight should be near 2700 pounds and I'll between 400-500 hp.
In 1982 a Bruce Wilson went 9.710 @137 in a 1/4 mile. In a Jaguar XJS V12.
In reply to Stampie (FS) :
Have fun with that next drink. Good night.
Hang on!
Once again... if this is a Challenge car, then MOST of the drag racing answers are irrelevant.
Reaction times DO NOT matter at the Challenge. Only ET.
The ENTIRE event is a compromise on EVERYTHING.
And it's important to understand the dynamic times. The autocross and drag race times are added together, and considered as a single dynamic speed number. That means you can win with a car that is good at one event, and not so good at the other.
I set up my cars to be easy to compromise. My cars are mostly autocross- I'm not a drag racer. So, I set them up to run flat in the corners. To get some weight transfer in the drags, I switch to big drag tires, put shims in the rear subframes to lift the body higher (and get it off the tires), and disconnect the anti-sway bars. Lots of changes in tire pressures. If I have adjustable shocks, I also switch them from full firm to full soft.
My Miata ran 12 second ETs, with a 1.6 second 60' launch. That's not the best drag race time, but it's pretty darned good for a Miata sitting on an IRS. And it's competitive enough. It was a podium finish overall. It was 2nd in the autocross (the part I'm a little better at)
Build the car you are most capable of, then figure out what compromises you can make easily to compete in the other event.
Pete. (l33t FS) said:
Your reaction time will be really bad, however, and you just gave your opponent a 5 second head start because the race is won by who crosses the finish line first, not who had the quickest time.
Pete, this is incorrect.
It's correct for drag racing, but incorrect for the Challenge. ONLY ET. The race is won by the person with the quickest ET, NOT the first person who crosses the finish line.
Frenchy is not actually asking about drag racing. He is asking about drag racing at the Challenge.
Without good tire size/choice how soft or stiff the back is won't matter quite as much. There are times that you can make the tire more of the suspension and make it work for you. A tenth in 60' is worth double up top, and is usually hard won.
frenchyd said:In reply to Cooter :
Here is my tentative budget for the Challenge. $500 car and I get to sell parts of it equal to 1/2 of my purchase so net $250. ( actually probable retail value many times this )
1984 Jaguar XJS $250
Two T4 turbo chargers $220.
Connection tubes etc $345.
Regrind stock camshafts $245Gasket set $87
12 used injectors $35
Grind valves $240
Ethanol sensor $20
fiberglass for hood, trunk lid, and door skins $250That should be about $1700.
Weight should be near 2700 pounds and I'll between 400-500 hp.
In 1982 a Bruce Wilson went 9.710 @137 in a 1/4 mile. In a Jaguar XJS V12.
Again the rules are at https://2000challenge.com/rules.
Looking at your list I see things you miss so let's organize.
1984 Jag XJS $500
Turbos $220
Turbo Tubing $345
Regrind cams $245
Injectors $35
Gasket set $87
Grind Valves $240
E85 Sensor $20
Fiberglass $250
Guessed total $1942
Recoup:
Jag XJS $500
What I see missing
AutoX tires $200 (2 exempt 2 used)
Drag tires $0 (2 exempt)
Drag wheels $50 (Assuming using stock wheels for Autox)
MegaSquirt $200
Cage Tubing $200
Total Missed $650
So grand total is Guessed $1942 - Recoup $500 + Missed $650 for a Challenge budget of $2092. No bueno.
Edited as I missed stuff but really question $35 for used Injectors.
SVreX (Forum Supporter) said:Pete. (l33t FS) said:
Your reaction time will be really bad, however, and you just gave your opponent a 5 second head start because the race is won by who crosses the finish line first, not who had the quickest time.Pete, this is incorrect.
It's correct for drag racing, but incorrect for the Challenge. ONLY ET. The race is won by the person with the quickest ET, NOT the first person who crosses the finish line.
Frenchy is not actually asking about drag racing. He is asking about drag racing at the Challenge.
That is the way I understood the Challenge worked, it is more like time trials where two cars are run at a time to speed up the process. But, you know, need to differentiate how reaction time has nothing to do with your 60' or your ET.
Racin' is fun, though!
I kinda miss the days of seeing a GN sitting at the line forever, slowly winding up, and then still managing to catch up to the other car and win.
Pete. (l33t FS) said:I kinda miss the days of seeing a GN sitting at the line forever, slowly winding up, and then still managing to catch up to the other car and win.
I don't think I ever saw a GN cut a good light when I was drag racing... and you hardly ever saw them running brackets. LOL.
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