Hey guys, I just ran my 71 Skylark and it went 12.96 @ 104mph. I'd like to see 12.50/60s out it without opening up the motor. Here's a run down for what the car is now. 71 Skylark 3925 with driver weight, goes 14.9/15.0 off bottle low compression 350 stock unknown mileage 130psi cranking compression. Poston intake Holley 670 Street avenger vaccum secondary, K&N 14x3 1" open carb spacer Electric fan NO A/C 2 1/4" exhaust with 2 chamber Flowmasters (stock manifolds) HEI distributor factory settings total timing 30 with NOS on AC 43TS plugs .035 gap Cheater NOS system with 53/61 jetting 12 bolt posi with 3.73 Th350 with shift kit The tranny upshifts at 4700 and goes through the lights at 5000-5100rpm. 275/60 15 BFG drag radials If it didn't list it its STOCK. I'd like to find 3-4 tenths for under 500$ total parts cost. I've got parts to upgrade the fuel system. So thats covered. I'm just looking for any "missed" areas for potential HP or TQ gains I might have missed. Any aero gians? I've got no grill in it right now. Would a ram air system help? Thanks Nick
Great start! Now go with a set of headers, 2.5" dual exhaust, 850 cfm Mighty demon or 800 cfm Q jet, loose 200 pounds somewhere in the car and you'll be in the low 12's. Yes a ram air setup will help a bit. Here are some more tips: http://www.v8buick.com/showthread.php?t=110669&highlight=nitrous+350 http://www.v8buick.com/showthread.php?t=86721&highlight=nitrous+350 http://www.v8buick.com/showthread.php?t=110669&highlight=nitrous+350 http://www.v8buick.com/showthread.php?t=86721&highlight=nitrous+350
You need to focus on the exhaust, not the intake. Get yourself some headers. Also, you might want to consider a cam with more exhaust. And maybe some of those electric exhaust cutouts - yummy. -Bob C.
I agree with the others, a set of headers would be next on the list with a good 2 1/2" exhuast and an X-pipe if you don't want to run open headers. You should also look at richening up the mixture when you put the headers on. Man, this makes me want to add a nitrous system to my 350 as it runs mid 13s @99 with a 3.23 gear and crappy street tires. What nitrous system are you running?
hey nick thats an awsome et for ur car. was that on the stock camshaft? as for a little better e.t. how about skinnies up front. also dropping lbs. from the car will help alot. how about some suspension tuning. have u tried manually shifting the car. yes headers and ram-air would help a bunch too. good luck and keep us posted. hey shawn u been up all night?:3gears: ralph
Thanks for the feed back so far. I've got some more details and questions with the suggestions. Its a stock LONG BLOCK in the car. On the chassis dyno the motor made 210whp@4600rpm/270tq@3750rpm(starting rpm for dyno runs). 100 shot made 280hp@4700rpm/350tq@4100rpm. 60' times are in the mid 1.8s leaving with the car just off idle and spraying about 5 feet out. Any sooner and it will spin the tires hard and then I'm in the 1.9/2.0s. Nitous system is an old NOS Cheater system, that I got off ebay. I know I have some left in the car with a tune, right now the carb has some drivablity issues but works good at WOT. So when I'm on the line I'm literally holding only 1200rpm then i just floor it and hit the Juice and instant later. Rear suspension is UMI adjustable uppers with boxed lowers and relocatoin traction brackets. I've yet set the pinion angle just installed at stock lenght. The rest of the suspension is stock springs all around rebuilt front end all bushings/joints, etc. Shocks are cheap monroes. Tires are 275/60 15 BFG Drag radials, and I had the pressures down to 16psi I started at 20 to begin the day. Didn't seem to change how it launched much though. Front tires are 245/60 15 radial TAs at 45psi. Also hot lapping the car nets identical times basically, long cool downs don't help at all. As for taking weight out of the car Theres not much to remove, other then doing the Glass hood and bumpers I want. An aluminum driveshaft would be lighter then the indestructable 1200hp rated one I've got in the car now. How big could I go on the motor Carb wise? With out going inside the motor, internal work is not an option for this motor. I thought the 670 thats on it now would be about ideal. Anyone got some cheap used headers laying around? Thanks guys. Owning this car has been a blast so far. I've got a video of one of the runs with the car, just not sure how to connect the link.
You don't need any mods for a larger cfm carb. Stock size was 750 cfm so 750-850 is ideal. Chevy and other smallblocks are happy with small carbs but these motors love the fuel. With porting and larger valves they like a 850 Demon or 1000. You'll want to get the mechanical advance limited via bushings so you can run more intial and use lighter springs on the mech advance (crane kit) to get it all in by about 2300 rpm. Aim for 34 total timing plus vac. advance away from the track (disconnect when racing).
hey nick im really impressed with ur car sounds like u have put some testing into it. id ditch the 245 front tires for some cheap skinnies. this will give u some reduced weight and less rolling resistance. ditch the back seat and a bucket seat if u have them. mind u this is for racing only unless ur only running ur car at the track. i agree with shawn about using a 750 cfm carb. how about a higher stall. maybe a 2200. as for headers, i think there was a guy here looking to sell his for around $130. ur pinion angle should be fine as is. how about air bags for the rear springs to pre-load the rear. chill the intake manifold with an ice bag before a run is an old racers trick. if u run alot of juice i would keep my total around the 30 to 32 range. set ur front end up with a drag race alignment. i think drag radials require more pressure than 16 psi dont they? these are just some suggestions i thought of off the top of my head. there are more if u need. good luck:beer ralph
I'm really liking some of these suggestions. I didn't think about recurving the distributor. I had it setup for 34 total, but pulled 4 degrees out to run the Juice. I was getting minor detonation with 32 in it. So its total 30 now I think all in around 3000ish. As for a converter, I'm afraid of changing that out, I hear too many horror stories about them. I don't want the torque from the nitrous to blow it to bits, my tranny works so good right now, I'd hate to blow some inexpensive converter. I agree that a 2200rpm converter should be right were I need to be though. There is a guy on here with a HUGHES converter right now, but he had it behind a V6... As for a carburetor, I know I don't need to change anything to use a bigger one. I'm just concerned about "over" carbing it. I have a Holley 750 sitting on the shelf, I can try that out. And put it back on the dyno to see how it does. I don't know the next time this car will be back on the track. I just put 35 passes on the car in the past 2 weeks from 2 different days. I'm hoping to hit Englishtown for a Buick vs Ford day to have some fun. Got a link to those 130$ headers?
hey nick i would definitly try the 750 holley. as for the headers get member sixtysix467 and see if he still has them for sale. i found this under the parts wanted section. good luck:3gears: ralph
Hey Guys, I figured I'd bump this back up again. Some updates are that I know have that 750 holley on it and it runs strong, definatly picked up some top end with NO low end losses at all. Also of note, I've noticed that if I hold second gear till 5000-5100 rpm it pulls high gear much harder. I think it winds up directly on the torque peak based on the dyno numbers. So I'm thinking I should be alittle closer to my 12.50/60 goal. If anyone has any other ideas to offer to me I'm open to all suggestions. Nick A. PS No updates for the past 2 months due to it being parked.....soon to be on a track again to verify upgrades.
What's your 60' time? I'd put in a good torque converter, a stocker kills your ET. Anti balooning plates, all the options. Won't be cheap, get a good one (I'm very partial to pro torque), just make sure you have enough tire to hook it.
Keep looking for those headers! I picked up a set of 1 3/4 chrome TA Super Comps in excellent shape for only $300. You can find them, just keep an eye out, and post in the Parts Wanted forum. I got mine swapped in a week ago, and this morning had a shop hang my 2 1/2 TA exhaust system. Just couldn't get it done at home w/o a lift... I pick up the car in a couple hours. :3gears: Put my MT ET Streets on too, hoping to find a 14.** 1/4 time.
Good Luck Dave on your 14.xx attempts with the car. As you car see with my combo its extremely simple and it got me to a 14.9 ET. I still look for headers but I'm not willing to spend more then 100-150$ on a used set. As far as a converter I agree 100%, but I will only consider an inexpensive one at this point, since it would need to be replaced once the new motor goes in. As for 60' times the stock converter is killing it some, 2.14 best with 2.18/2.22 average on motor. When I spray the car it goes into the 1.84-1.88 range pretty consistent. On my drag radials. On slicks with a 150 shot it went 1.77 60' time, but leaned out and killed a plug. For the street just leaving the 100 shot jetting in is a killer setup. It'll run 13.2-30s like that all "night" long. Once I get the fuel system upgrade taken care of, I know the car will be able to run deep into the 12.sssss. To think that a 14.9 car could run 12.2-40s with just a 150 shot....I think its doable. Once again guys thanks for the input.
The better units can be restalled pretty inexpensively...Most offer one free restall within a year or two of purchase. My GN would 60' 1.52 like clockwork on a zero boost launch when I had the converter I wanted in the car.
Once you get a set of headers on it you should notice a BIG improvement on the top end of each gear. I shift my 350 at 5600 rpm and it is still pulling! I've been running a Daaco converter that was one step above stock for the last eight years with no issues, was about $200 when I bought it.
You might even try 28 and see how your ET is. Combustion is faster with nitrous, so you might pick up ET by not following the "as much timing as possible without knock" rule of thumb and retarding it slightly more. -Bob C.
30 degrees on a low compression 350 is a bit low. It shouldn't detonate. You should be able to run 32-34 on a 100 shot. I would say that the 670 had a lean spot in the fuel curve that was causing your problem MOST likely because it was a vacuum secondary. I would say try a little more timing with the 750...like 32-34 total. How do all the plugs looks after a run? How much fuel pressure are you running? There is a little better jetting you could use on that plate if you want a little more out of it. NOS jetting is rich unless you aren't running much fuel pressure to it. Get it to hook out of the hole and it will be faster... If you want more out of your Nitrous you need to look at getting a different plate since you are spraying everything out of the plate into the wall of the intake....including the fuel out of the carb
