If you have desktop dyno, please help me. I just had a baby and cant afford one. [Archive] - Chevelle Tech

: If you have desktop dyno, please help me. I just had a baby and cant afford one.


QAK
Jan 23rd, 99, 3:27 PM
If you could run these #s and tell me what my combo makes id really appreciate it.
It is a 461 with 11.1 comp, Square port c-chamber heads w/full porting and pol. Comp cams solid. 638int, 631exh, @.020 dur int310 exh314, Valve timing-@.020 int open-47btdc Close 83abdc. Exh Open 85bbdc, close 49atdc. For cam installed @108int centerline. Dur @.050 is int-270 Exh-276...lobe lift int .375.....exh .371 with matching double springs. Weiand Stealth dual plane int. 800 dbp holley, mallory unilite. Car is a 68ss396 3700lbs with driver. t-400 w/4000 stall. 4.11 gears, 275 60 15 m&h slicks. If you can help me i would really appreciate it. Thanks.....Chris. By the way the car has run 12.11 @112 mph. Does this sound right??...i thought with all that motor it should have run allot quicker than that. Like maybe 11.40s at 122mph or so???

swild
Jan 23rd, 99, 4:07 PM
You should be able to sell your story for millions of dollars to the tabloids! It's not every day a guy has a baby. Sorry - couldn't resist.

Steve

Brian n az
Jan 23rd, 99, 6:14 PM
Go to www.rconcepts.com. Check all their links, you will find a decent program that
gives you 1/4 mile times for free. It's not quite like Desk Top Dyno, but it does give you some good info. Now if any one will make a desk top dyno that shows times and $$$ needed to get there, I would buy it.
Good luck, nice car.

Brian

1bad67
Jan 23rd, 99, 9:22 PM
Dyno estimated 500 HP @ 6000 / 469 ftlbs. torque @5000. Car should run elevens. both ET and mph are down. Tried jetting timing ect.? Also if that is correct, whats the altitude of your local track? Cam is a good choice says dyno a cam profile change nets 5 more HP. Were a roller cam will give you about 30 more HP. An increase in cfm shows benificial. I think altitude is your problem.

QAK
Jan 23rd, 99, 9:56 PM
Actually altitude i dont think is the prob. Here in Kansas its only 751 ft above. Only 500hp??. WOW was i ever wrong. I figured around 560 or so. Well it runs strong and the cam really isnt too big for the car as ive tuned it to an inch of its life *L*. Thanks for the reply guys......Chris

1bad67
Jan 23rd, 99, 10:08 PM
What is tour total advance timing? Or maybe the converter you have is slipping? One thing about desktop dyno is head selection is brief. For a big block like yours I would think your MI. should be 118 n up. Thats why I think maybe converter since your at sea level. Its tough to sort this stuff out I've been there.Good luck Trash that mallory when you have the $$

ratuned
Jan 24th, 99, 6:25 AM
I ran it thru my desk top dyno and desk top drag and these are the numbers it spit out.
588 H.P. @6500 rpm
516 torque @ 5000
E.T. 11.11 @ 121 mph tripping the lights @ 6500 rpm.
60' is 1.60
1\8 mile times were 7.08@99 mph.
I had to use open headers with large tubes in the menu, another note is that there was a dip in the power curve and it made more power @ 8000 rpm to 590 H.P. I think that your est. are in the ball park. the programs are def. generous but they have come pretty close in quite a few cars that have been built. I chose shift points of 7,000 rpm. things to look at now are, was the head work done at a rep. shop, you may not have enough tire and susp. work for that much motor. How old are the slicks and are they true slicks 0r street legal DOT that may not have enough bite. your MPH seems to be off, How about your fuel system big enough? properly routed? How about your susp? proper weight transfer? drivetrain slippage? the list goes on. good luck

QAK
Jan 24th, 99, 8:52 AM
Ratuned, thanks....i thought it should have made that much power. I think the biggest thing killing it is the intake. I need a good open plenum one. Im getting a bit of reversion i think. I need a bigger carb too, like a 950 or so. The fuel line is only 3/8 and im losing pressure thruout the run. It goes down to 3-1/2 to 4 pounds. NOT GOOD!. The conv. is a GER 4000, i think it is slipping a little. Just dont have the money right now for a good one. Slicks are M&H DOTs, 275 60 15s. I also need to replace these with some better ones. Did the program show any improvement with different slick sizes??. Thanks so much for the info.......i really appreciate it. CHRIS

ratuned
Jan 24th, 99, 3:44 PM
It sounds like you have a prety good idea of what your problems are. What were your 60' times? I would recommend working your fuel system and change only 1 thing at a time to isolate what the proglem is. lotsa luck and please let us know how you make with the changes.