73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Performance => Topic started by: a t5 chevy on April 02, 2008, 12:08:37 am
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My daily driver is a 85 c-10 2wd swb. This past weekend I took it to the local dragstrip to see what it would do. My best run was (dont laugh) a 16 flat in the 1/4. My main problem was that i couldnt get it to hook up until i hit 2nd or 3rd gear (i had my half bald stock tires on the back). This was nowhere near what I think it could run (mid 13s). What do yall think would be a decent time for me to expect if i could get traction with its current setup, or have i set too high of an expectation? Any help would be greatly appreciated.
Here are some basic specs on the truck:
'77 350 sbc
stock longblock
comp cam (230 duration/480 lift) w/matching valve springs
holley 4bbl intake
600cfm holley carb
headers w/3" duals
Godley performance 350 trans w/shift kit
2300 stall
12 bolt open diff w/2.73 gears :'(
lowered 5"f/4"r
18" coys wheels front and rear
weight is pretty close to stock
As my budget allows, the next upgrade will be 3.42 gears and a limited slip.
thanks
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You might get low 15's. You will need at least 450 hp at the tire to get into the 13's...
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A CC Magnum 280 for your daily? Cool. With that cam the cork in your performance is the heads and the CR. You should have the heads pocket ported and machined for large valves. What is the compression ratio? With a stock short block, probably around 8:1, right? That cam is gonna want at least 9:1, I would think. You could always kill two birds with one stone and bolt up a set of vortec L31 heads, with their 64cc chambers. But those heads are gonna want a dual pattern cam (maybe an XE274) as they have E/I ratios in the 65-70% range.
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Thanks for the help. Yep its the 280 magnum, has a good thump but likes gas. The CR is stock as far as I know. I plan on getting a pair of Summit brand iron heads 2.02/1.6 with my tax return. Until then Ill try to lighten the truck as much as I can. What would be some good parts to remove to lighten the truck? There's a test and tune at the local track on the 11th that Im gonna try to go to, hopefully with a different rearend and some drag radials. again, thanks for the help and keep it coming.
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If you are spinning into 2nd and 3rd, making it lighter will make this worse. You don't really need to worry about removing weight until you get her to hook out of the hole. Do they use track bite or any other surface prep (traction aditive) at the strip?
The upgraded gears and posi will help out alot, but like stated above you really need some heads on that puppy. You have the exhuast took care of, she needs to breathe a little better though.
Find a set of double hump heads and bolt them on, around here they can be had for alot cheaper than a set aftermarket heads.
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I think a set of slicks or ET streets would make a huge difference. A guy from my town would lose pretty bad to a headers only Dodge Ram(Hemi). After he installed his posi(actually a spool) and put on some sticky tires(ET Streets), he beat the Ram by a few cars.
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What's your MPH?
how bad was your 60' time?
4400 lbs with driver + 300 hp approx = 15.20's with perfect hookup
You are gonna need another 100hp to get high 13's low 14's
Have you seen the Patroit heads
here's a set on Ebay
but Patriot sells factory direct (approx $800)
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33617&viewitem=&item=270223060227&_trksid=p3907.m29
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Yeah they use some kind of chemical on the track. Everyone that had decent (not bald) tires hooked up real good. I went to the junkyard at lunch trying to find a rearend, but every 12 bolt posi i ran across was in a 4wd (6 lug). What vehicle (pickup, blazer, burb) would be my best bet at finding a 12 bolt posi in with 5 x 5 lugs? I found some camel hump heads, but they're gonna need a little work before they're ready to go on. Also what drag radials would you suggest for a tight budget? Thanks
R/T: .538
60': 2.497
1/8: 10.319
MPH: 69.77
1/4: 16.001
MPH: 84.13
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Welcome to the board t5...you can use the 4x4 rear end if you are willing to swap your axles and brake drums from your 2wd rearend.
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Thanks. I'm definately gonna try that. Sure beats $800+ for a new limited slip, axles etc. In general what was the most common gear ratio on 4wd rearends?
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I personally see a few things of mention here. 1) That is way too much duration for a stock 8.1 engine, all of your cylinder pressure is lost. 2)The 2.73 one wheeler rearend isn't doing you any favors 3) Regular street tires are not going to produce the best track times. On a side note, I don't believe you truck is quite as heavy as the 4400 mentioned, Have you weighed it? My SWB truck with the big block Olds weighed 3910 w/me, last time on the scale. This is a complete truck, heater, carpet, bench seat, but no tailgate. I'm about 230lbs. However I have to say "I think your a bit optimistic" on you 1/4 mile expectations. Don't bother with the old double hump heads, by the time you buy them & get new guides, seats, valves, springs & machine work, you could buy A/M heads. You should plan on small chamber heads to help raise the compression. Just my take on it, Lorne
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4400 would be closer to a long bed that is fully loaded with a 454 generally they average 4200lbs. Short beds run around 3900lbs
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3900 lbs sounds right. I'm cautious though about saying 400+ HP is needed to get it into the low 14s. I'm just saying this though from my own knowledge that my 4400 lb 2005 Dodge Magnum R/T with it's stock 340 HP Hemi can do mid-low 14s, even with it's ridiculous 2.82 rear gear. The 2.73 gear and the tall-gear TH350 maybe is the key factor there, along with the stock heads.
For heads, you might as well go GM Vortec, Dart Iron Eagle S/S ($695 pair with 2.02 valves) heads or the Summitt's like you mentioned. Camel heads are alright, but now there are better for same or less money. Cheapest alum. heads out there are those Patriot's as mentioned. Don't go over 180cc intake runner volume though IMO. That 3" dual exhaust too would make better use of a better flowing head.
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I said 450 for the 13's not 14's?
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True dat, you did. Are there very many people here that run say sub-14 second 1/4 miles? I know team39763 with the 6.0 swap in his 82 runs high 12s which is amazing considering how mild his setup is, although not many of us run 4.56 gears and slicks!
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Don't forget I said 4400 w/ driver
add fuel and a spare and whatever you have under/behind the seat
my 82 short bed stepside 2wd weighed 4400 with me in it last time I went across the scales
of course both tanks were full......
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Sux, Last trip to the track I went 12.40's @ 109mph in street trim. A little lighter now & moved some weight to the rear (fuel tank) to help with traction. Hope to be holding an high 11 before summer is over. Built out of parts most guys going racing would throw away. Lorne
(http://i163.photobucket.com/albums/t285/HAULINIT/LornesTruckPRP.jpg)
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^ That's awesome, Lorne. It seems hard NOT to run 12's in pretty much anything that uses an Olds, or even a Buick or Pontiac 455. The power that can be unleashed from those things is crazy. I imagine you had to make custom motor mounts to get that in there? What about the tranny?
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well to give you an idea i ran my truck at MMP and i got a 15.20 @92.
at my local 1/8 mile i got a 9.90 @ 74.
my setup is nice but still needs work.
and mine is a long bed truck.
and i still got a stock 10 bolt 2.73.
60 fts were ok like 2.2's
and like haulin it said that cam is too much for a low comp motor.
needs to be around 9.5 or so.
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Sux, I'll send you a PM a little later, I don't want to get too far off of T-5's original topic on his post. Anyone else with questions, feel free to ask. Lorne
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Hauilin it, why not just make another post?
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Capt. I can. I just wasn't sure there was much interest in what I'm up to (Olds engine, drag race, ect.) Is the Member's Ride's section where you would like it? The truck, like many is really a on-going group of projects, so I wasn't sure. Lorne
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I RAN 14.5 THIS WEEKEND WITH A 350 HO CRATE WITH 330HP AND A 3.73 IN THE REAR, I ONLY HAD ONE PASS ON THE TRACK AND THINK MY TIME COULD OF BEEN BETTER WITH MORE ATTEMPS.
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I RAN 14.5 THIS WEEKEND WITH A 350 HO CRATE WITH 330HP AND A 3.73 IN THE REAR, I ONLY HAD ONE PASS ON THE TRACK AND THINK MY TIME COULD OF BEEN BETTER WITH MORE ATTEMPS.
I'm betting the line was too long for you to run again...right? I heard that the wait time is like 1hour sometimes down there at HRP. But everybody says it's worth it because that track is prepped real good.
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i run 12.0 in my 83 silverado 3264# though !
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Sbc, Good Job! 11's are right around the corner. Lorne
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T5, some drag radials will definetely help your cause, your 60 fts are killing you. anything you gain in your 60's will double in your ET. I don't see any 13 sec timeslips in your near future unless you do some upgrading however, but some low 15/high 14's are definetely in reach. you won't need 450 rwhp to get 13's but you will need 400+ flywheel hp to. I was running 13.7 w/ a 425 hp 454 ( guessing on hp ) and 1.9x 60 fts. I ran some 275/50/15 MT ET radials (26/10.5/15) and they would dead hook my current 496. 3.42 gears are a good street/strip gear and 3.73-4.11 are a good strip/street gear. until i put my 496 in I was lucky enough to have OD so I could run 3.73s and 27" tires and still knock down decent mileage while running 13's. Patriot makes some excellent budget SBC heads worth looking into to raise your CR and up your flow. Keep racing and enjoy watching those numbers drop!
Ps- my all steel 85 w/ iron headed BBC weighs 1990 KG ( 4378 lbs ) w/ me in it and one tank 1/2 full.
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Thanks for all the help. I decided to go with an auburn gear limited slip instead of the old gov-loc after hearing some horror stories. I also installed a 3.73 gear set from richmond and some 275/60/15 hoosier drag radials to run in, and boy do i love it, gas doesn't tho lol. I took it to the strip this past sunday to try it out and my best run was a...
13.953 in the 1/4 @ 98.67mph
8.957 in the 1/8
2.020 @ 60'
Motor wise the only thing that i changed was a new 650 holley carb and a k&n air filter. Again, thanks for the help. This website has been a great resource.
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congrats t5, you're hooked now buddy ;). if you haven't already and you have the shorkel type air cleaner, you can cut the rain guard of the air intake beside the rad and you then have a 3+" ram air system. you can carry a spare non-cut one with you behind the seat in case it rains. :)
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^ Hey 85shorty, I see you are a fellow BC dude too. I'm down in Chilliwack and also have an 85 shorty 2wd. I checked out your cardomain page. Pretty nice ride, and quick too! So you rebuilt the 496 and 40 min. after it was done you took out a piston? Or did I read what wrong? I didn't even know Chetwynd had a drag strip. I thought Mission and Ashcroft was it for the province. What does your buddy Dean's truck have in it to run 14s? A 350 I read, but what kind of mods?
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yep, 25 min cam break-in and 15 min later the piston basically fractured ( we're guessing, couldn't get a replay on the in cylinder camera ;D) and the wrist pin went thru the cylinder wall, bent two valves cracked a valve guide and broke two pushrods. didn't even get to drop the hammer. got it rebuilt now and it's running well. race season is about to start. Chetwynd is a once a year event on the local airstrip. we have a full time track in Fort St John that has a race once a month and a track in Fairview 1 per month as well. Grande Prairie also has a 1/year enent as well. Dean's truck is just a warmed over 350, nothing to special. stock heads, moderate cam, Edelbrock intake and 650 cfm carb, headers and exhaust. he has a th400 tranny with a loose 3500 stall and 4.11 gears which are the main reasons for the quick times I think.
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Right on. That totally sux about the piston though. I bet that was hugely aggravating to just get a motor together than to have it grenade and cost a bunch to fix up again. Fort St John has a dragstrip too?? Wow, would have never thought. I know a guy who just moved up there to be the ambulance station chief. His family is up there too (last name Key). That's very interesting about your buddies truck and running 14s with such a mild combo. The gears and converter are definitely helping that one by the sounds of it.
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Nice work T5. I think you have me beat on the 60ft and we're pretty close on the 1/8mile too.