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Post by n2ojoe on Oct 23, 2017 18:55:54 GMT -8
I haven't had a chance to run the car since the pure stocks, so I took it to Milan yesterday for our club day. The only change I made was VP C12 fuel instead of 110 octane, and it responded with a new personal best! 1.94 60', 13.52 @ 100.4 mph. Still feels out of motor near the traps though.
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Post by sc397 on Nov 2, 2017 7:49:36 GMT -8
Nice job Joe! Mid 13's on Bias Plys is impressive.
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Post by nejoe2 on Nov 3, 2017 0:50:18 GMT -8
Joe, what's your opinion of the dr diff axles? Besides having to shorten em to the length you need. I'm gonna be doing a 70 rear with the same axles and a spool over the winter. Curious, what type of bearing do they supply with the axles,tapered roller, ball, etc. I've heard similar to moser, whereas it doesn't allow outer seal to be retained? Any info appreciated! Thanks.. The axles are a pretty nice quality overall. I had a few minor issues with the install though, but nothing too serious. The bearings are a sealed design, and come with new inner seals for the housing. No outer seal is used, so I cut the rubber from my originals and used the bare seal plates as axle bearing retainers. The problem is once the wheel bearing and bearing lock collar are pressed into place they are too close to the inner grease seal and the collar rubbed against the seal at first. It took extra effort with a seal driver and hammer to get the seal into the housing just enough to clear. The instructions say to press on the bearing with the part number towards the inside. The bearing inner race protrudes slightly more on that side than the other, which also doesn't help the problem with clearing the seal. I might try pressing the bearing on reverse if I install another set. Also, the wheel studs are a screw in race type and very long. I have tall acorn lug nuts that wouldn't quite tighten enough. The axle flange register to center the wheel is also tall, and my Machine wheel center caps wouldn't fit over them. A 5/16" wheel spacer was used to fix both problems. thanks!
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Post by n2ojoe on Apr 18, 2019 20:19:41 GMT -8
Small update on one of the ideas I have for this season. I sketched up a rough drawing for my "poor man's Rebel Machine exhaust manifold" and set Kevin loose with it. Since I refuse to pay $1500 for the real deal just to get the 2 1/4" outlets, as opposed to the standard 390 2" outlets, this turned out to be a good alternative. It's a simple adaptor plate that attaches to the stock manifold using the flat gasket from the heat riser valve, and replaces the stock 2" doughnut gasket with the later high flow manifold 2 1/4" one. Kevin whipped up a few plastic models with a 3D printer to test the fit, and we settled on the more compact design for clearance. He also had the great idea to use the tapered screws to allow the plate to be 1/2" thick to reduce weight and make the machining process easier. I plan to have these in place for GAD to get a good A-B test over stock, before I make any other changes. Yeah, it's alot of work to meet "pure stock drag" rules but I think it will help it breathe better. Hopefully the pics do the rest of the talking. Thanks Kev! 20190316_165608 by Joe Pinsoneault, on Flickr 20190313_1217291 by Joe Pinsoneault, on Flickr IMG_20190317_174531 by Joe Pinsoneault, on Flickr 20190418_133608 by Joe Pinsoneault, on Flickr 20190418_133647 by Joe Pinsoneault, on Flickr 20190418_133804 by Joe Pinsoneault, on Flickr 20190418_133845 by Joe Pinsoneault, on Flickr 20190418_133949 by Joe Pinsoneault, on Flickr 20190418_134255 by Joe Pinsoneault, on Flickr
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Post by 69Rebel on Apr 18, 2019 21:25:09 GMT -8
Being stuck with the old log manifolds has got to be the shits.
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Post by javtwotone on Apr 19, 2019 5:38:49 GMT -8
Where did you make the transition from the 2" to the 2-1/2" pipe? Just curious how much pipe you get to replace with the very cool modification.
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Post by Captain Awesome on Apr 19, 2019 6:13:16 GMT -8
That's cool. I like seeing the little tricks.
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Post by n2ojoe on Apr 19, 2019 6:23:34 GMT -8
Yep, these manifolds certainly do suck. The exhaust had a 2" ball flange at the manifold that I flared to 2 1/4" diameter at 2" length out, then to 2 1/2" diameter by 4" length (kind of a short megaphone). It should be easy to cut that first 4-5" section off the top of the headpipes, then butt weld on the new Walker flange pipe since it is already flared open to 2 1/2" O.D.
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Post by stickshifter on Apr 19, 2019 7:40:57 GMT -8
It's nice to see that they actually fit the manifold and the new pipe. Sometimes I do get lucky.
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Post by spud on Apr 19, 2019 8:06:48 GMT -8
Ok. Now i know your in the middle of this, but you might want to consider the venturi tech that is developing. Venturi collectors in headers and venturi inserts in exhaust are making power! What if.. your adaptation incorporated a venturi?
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Post by spud on Apr 19, 2019 8:14:50 GMT -8
I dont get the nhra. They let the earlier cars run dogleg heads why not let you run 71 freefow manifolds. Nhra Stock class is brutal.
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Post by n2ojoe on Apr 20, 2019 5:26:22 GMT -8
Spud, do you mean something like this? Interesting idea, but I'm not sure where the optimum placement would be without trying several locations. www.summitracing.com/parts/cci-psbi250c/Also, it's not NHRA's fault (this time). The pure stock drags are just a group of muscle car enthusiasts with the intent of racing the cars for fun, with all of the original equipment in place (but well tuned). A few changes are allowed, such as 1.5 points of compression over stock, up to .070" overbore, max 2.5" dia exhaust, any rear gear ratio. www.psmcdr.com
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Post by spud on Apr 20, 2019 8:45:17 GMT -8
Yes, that is one product i have seen that applies the concept. Schoenfeld has been experimenting with it, i have seen merged header collectors , with “ megaphone” outlets that are honest venturis. So apparantly the practice of putting a venturi in the exhaust flow, after the individual pipes merge is proving beneficial to scavenging. I dont know anything about pure stock, or what is allowed. I would think a freeflow manifold would be a big advantage over a logjam if allowed, but i guess its not. In that light, i would be very willing to weld in some venturis soon after the manifold , just to see what it does. I think going to the 2-1/4 pipe may help. The adaptation you are using may help, it is somewhat of a venturi, but taking your adapter a step further, making it like two inch thick and actually machining a venturi throat in it, and even blending the manifold outlet some( well if pure stock allows light mods to a factory manifold) ... well thats an idea that is forming in my head with what your doing there... to “ transistion’ the flow into the pipe...
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