Landracing Forum
Tech Information => Steering - Suspension - Rear End => Topic started by: rebelce on May 26, 2007, 07:29:13 AM
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I've gotten to the point where it's time to start building up the rear end. I have a Ford 9 inch and was given a set of 35 spline Moser axles that are the correct length. I don't have a problem trying a spool and they make them for both the stock case and the larger stronger aftermarket cases. My question is simply, on the salt, do we have enough traction to warrant going to the nodular case? It's an XO/GR and will be weighing in around 3,000#. At some point fuel is also an option, that would put the hypothetical speed between 150 and 200.
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I never used the N case. never had any reason to wish I did. In fact my roadster with a V8 qc never had any breakage when Al had the blown Chevy in it.
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When racing the Merkur, I used a Strange Aluminum 9 inch housing and a steel spool. Engine made 525 lbs ft torque and never had a problem. (With axle failures I mean.) Weight was 4200 pounds wet. By all means use the alloy part if you are inclined to.
Rick
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IMO the only time you would have to worry about a 9" ford rearend in a LSR car would be if you had 1200 or more pounds of lead over the rear end and were able to shock load the drive train. 35 spline axles were originally made for drag cars they should have more than enough strength. There are more efficent rearends out there if you are going to be limited on HP. That might be something to consider also, but just depends on your budget. Good luck.
Tom G.
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Speed has nothing to do with it at all.. Think ft/lbs.. I would be more worried about it with a diesel and super low gearing going 2 mph pulling a big load..LOL.. I would go for the most efficient gear design rather than a brand. I would also think light for unsprung weight. Currently to my knowledge a spiral bevel lowest drag gearset (Hewland uses them) and an alloy case a no brainer.. You don't have drag slicks or the bite associated so don't bother thinking drag race or even gears made for it they are heat treated differently for the shock loads..
Dave
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Unfortunately, budget constrains keep me from going with absolute efficiency. You have to do the best you can with what you have. It sounds like I could get by with a stock ford 9 center case and pinion support, the 35 spline axles and spool would add to the overall strength. Does that sound right?
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If you are going with the Ford you can use the 12 bolt Chevy drop in. This will help your efficiency with the better pinion angles. Finding gears is another story, but they are out there. Some of the truck gears can be used with a different pinion bearing. Are you using the NASCAR style floater rear end? If you are you can do some work on the hubs to minimize drag. I ran both a quick change (Halibrand) and a Ford 9 inch on a chassis dyno, before going with the Ford 9 inch. There are many other things that can be done to gain efficiency on the Ford gears to heat and oil control. We use an aluminum housing and an aluminum center section with a dry sump system. Mike Feldener helped us with the set up on ours. He is one of the best in the business and has set up some of the LSR cars and does many of the NASCAR team rear ends. If you want his number, PM me.
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maguromic
What where the results when you compared the 9 inch to the QC on the chassis dyno ?
John Burk
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Unfortunately, budget constrains keep me from going with absolute efficiency. You have to do the best you can with what you have. It sounds like I could get by with a stock ford 9 center case and pinion support, the 35 spline axles and spool would add to the overall strength. Does that sound right?
We understand "budget" and run a normal 9 inch (2.47 gears) with a spool and it has worked fine for us so far with Hooley's Stude. You will have no problems. Due to the traction there I feel you can get by with at least 40% more HP than you could at the drag strip. We ran a stock Muncie narrow ratio 4 speed (it's for sale) for the last 3 years likewise with no problems and it never would have held up at the drag strip. Granted at 241 mph we were running all the HP through it, but the shock loads just aren't there off the line or during the shifts. We have upgraded to a G-Force 4 speed this year for peace of mind and the option of being able to pick all the gear ratios with one being a 7% overdrive which lets us keep the 9 inch and still pick a final drive.
c ya,
Sum
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John,
I tested both at 2.47, from the quick change to the Ford 9” we gained about 6 HP. It was interesting when we went to the 12 bolt drop in and it jumped to 10 HP. My car is HP limited and runs on gas, so the only way is to gain the lost HP. Remember 75% of the horsepower loss occurs in the drive train.
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At one time I was real negative on the 9 inch efficiency but from testing that I have heard about and also thinking about it a little in the ratios that you would want at B'ville the 9 inch is a good choice. Unless you happen to have a couple of thousand HPs and a ton of weight to make it hook up you will never brake a 9 inch. When you get into the higher ratios, like 3 to 1 or less, the pinion starts to get lots of teeth and the sliding action between the pinion teeth and the ring gear greatly decreases and the efficiency goes up.
Another area is the gear oil itself. Run the lightest you can get away with and also the smallest amount. The real trick would be to dry sump the diff and spray the oil on to the ring gear just past the point of mesh. I talked to a couple of FWD guys once and they had a Chevrolet 4 cylinder with a BIG turbo, claimed it made 1800 hps! anyway they ran a 9 inch diff in the front and since the motor was infront of the front axle they ran a custom built gear box that changed the drive direction to get the power into the 9 inch. Well the custom box was pretty beefy and they normally ran 2 qts of 140 wt in it, they checked the temp one time after a run and it was over 250 deg F! so they next run they put in one qt of ATF,
No heat and they ran 8 or 9 mph faster and a couple of tenths quicker. So there is power in the diff.
Rex
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When we raced in IMSA in the 80’s we were backed by Ford. At that time Roush did his own tests with a quick change and the Ford 9” He also concluded that they were able to gain lost horsepower. All the GM factory cars also ran the Ford 9” till recently when all the factory cars switched to the Hewland.
The dry sump system I built is a copy of the one used on the Corvette Lemans cars. It’s a two stage pump driven by a electric motor (not the rear end), and Mike at Paterson built me a special tank. Working with the local college here we came up with a nozzle spray pattern. (the spray pattern is very important (like on FI system) or you will aerate the oil and loose horse power). Like Rex mentioned proper heat control is very crucial in keeping the tolerances set or you will get deflection and HP lost. I use a very light oil that I had custom blended for me. Depending on how much vacuum you are pulling from the dry sump system there are some other things that need to be done. If you want more info PM me.
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Seems like dry sumping the Ford rear end and using a lighter oil. Other than a custom blend, does anyone have thoughts on a lighter oil, perhaps Amsoil and building a windage system? I've picked up a two stage pump, so there's a start.
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Well, my pump came yesterday and it didn't help the decision making process. I guess I'm used to having a scavenge side and a pressure side but here I sit with a two stage pump and it's scavenge on both sides (two stage Stock Car Products). How the heck do you plumb a system without a pressure pump? Suck like the devil on the housing and let the vacuum pull the oil in from the tank?
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No instructions came with the pump?
DW
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If it sucks it in, where does it push it out??? Seriously, I have 1 or 2 laying around the shop I could dig out and take a picture or some other help if you need. Doug Odom in big ditch
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What you have is a circulator style pump, not a two stage dry sump pump. These are single unit systems used for circulating the oil in the transmission and rear end through oil coolers. They are made by all the dry sump manufactures but are not intended for dry sump applications.
Two stage dry sump pumps are common on some drag motorcycle applications and some dirt track and drag cars.
You can make your pump work, but you will have to calculate the amount of oil needed and restrict the oil in your return line as its a constant flow return. As these are circulator style pumps they don’t draw big vacuum like a dry sump pump.
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As it was ebay, so no instructions and yes that's exactly what it looks like, even if it was listed as a dry sump pump, both in the listing and the manufacturer web site. It looks like I might be able to bleed a little off the pressure side (as they are both the same) So that more is pulled out than put in. I hate doing it that was as it's needless waste of energy. But a good pump in the hand is worth two in the parts book and I've been out of the box so long it could work.
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Some things you might want to consider is putting a scraper for your ring gear as the oil will want to rope on the ring gear. When the car is moving the ring gear will push the oil to the shotgun side so think about your scavenging layout. Depending where you put your oil back you may not have adequate oil for the pinion bearing and you may have to plumb an oil line to it.
If you want that little bit extra, think about your hoses and fittings. All fittings and hoses aren’t the same. I only use Aeroquip because they are MIL spec. Others like XRP, Earls are good companies but they only use MIL spec as a guideline. With some of their products (on where they sourced it at the time) you can get flow disturbances or boundary layer entrapment causing you to loose what you have gained.
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John,
I tested both at 2.47, from the quick change to the Ford 9” we gained about 6 HP. It was interesting when we went to the 12 bolt drop in and it jumped to 10 HP. My car is HP limited and runs on gas, so the only way is to gain the lost HP. Remember 75% of the horsepower loss occurs in the drive train.
So I'm clear here - the Ford 9" gave you 6 more HP than the quick change? And the 12 bolt, was that 10 HP more than the Ford (total of 16 then) or 10 HP more than the quick change?
Thanks!
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With the Ford we gained 6HP over the quick change, when we put the 12 bolt drop in to the Ford 9” there was another gain of 4HP for a total of 10HP. This didn’t make horsepower. We gained HP that we lost by improving the efficiency. I didn’t check a regular Chevy 12 bolt rear end against these, but I suspect the results would be close. I wanted the Ford 9" so I can use the NASCAR style floater hubs and the ease of changing the gears vs the Chevy 12 bolt.
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[quote author=maguromic link=topic=2490.msg30798#msg30798 date=1182817310 I wanted the Ford 9" so I can use the NASCAR style floater hubs and the ease of changing the gears vs the Chevy 12 bolt.
[/quote]For 12 bolt on my Essex I used stainless tubes w/ 9" style brngs to eliminate C clips & use axles w/ bad roller brng area- would be just as easy to install grand nat tubes& use dble spline axles-giving option of toe in or out and + or - camber-{probably not needed for corning on salt} - gear changes will still be a little slow..russ
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rebelce, not that I'm confused but how are you going to run your pump? A belt off the drive shaft? Added drag (pump, belt, pulleys)
Nothing is going to happen until you start making your pass. Are you aiming a nozzle the intersection of the gears; not much pressure until you get quite a few rpm. There is alot of load on the gears at the beginning and the oil is sitting in the "sump" of the differential when it's needed.
IMO As you get up to speed the oils is thrown everywhere out the axles,etc and the ring gear makes a path in the oil so the not as much drag is there as you think..
I would pick a better designed rear with less built in drag and run synthetic oil. The more stuff you add the more can go wrong.. Murphy is built into all our races vehicles and loves to interrupt rides...Good luck
PS...The new 2 stage Barnes pump I bought off E-Bay was a true 2 stage. One suction and one pressure.
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As much as I love over engineering and needless complexity (not to mention the thought of horsepower lost) The KISS principle is very much alive over here and I need to start a little simpler in the beginning. Just getting there with a complete car is going to be hard enough without doing an absolute max effort. One thing this post has given me, was an appreciation of the different philosophies involved in racing. For what it's worth, I was planning to drive the pump via electric pump. I do think there is much validity in this train of though and congratulations on finding pump that is correct for dry sumping a rear end.
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One caveat about shock load on the salt not being comparable to asphalt, if you use a clutchless transmission with an air shifter, you will be putting tremendous shock load on all your drive train parts. They shift within a 1/3 of a crankshaft revolution. Lots of inertia and momentum change there that translates into a larger than expected shock load.
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:-o Amen Richard, that's why some of us old farts never wanted to do that. I always used the tried and true clutch. Then I know who to blame when something breaks. KISS philosophy.
Howard
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Thats what your right foot is for Richard.......... :-D
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just as rex said spray the oil after the gear mesh... logic will tell you to lube it before contact but you will detonate the oil under compression. lighter weight oil has a higher btu thermal reduction and can still have the same cushion to lubricate.
kent
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Rebecle,
When you say you have a double pump but they are both scavenger sections that is not really correct. You have a double pump and there is not a relief valve on one section as you would get on an engine pump. Well you really don't need a relief valve, one section should scavage your diff housing and pump the oil into a small external reservoir and if you really want the best possible oil going into your diff you should also put a filter on this line, the other section should pump out of your external reservoir, DO NOT PUT A FILTER ON THE PUMP INLET!!!!,be connected to the spray bars that you are going to install to spray the lube oil into the places that want lubricated in the diff. You really don't need, or want, a relief valve as the pressure in this system is going to be set by the flow rate of your pump and the size of the various lines and spray tubes that you put into the diff. On an engine system you need the relief valve to set the maximum oil pressure that the engine will see and the relief valve dumps the rest of the oil back into its own inlet port, you don't want this for your diff, you want all of the oil that the pump puts out to be put back into the diff. I would set up the spray bars with what ever you are going to do for nozzles and put a pressure gage on the pump outlet port and run the pump, I would suggest that you set your spray nozzle sizes to set the pressure at around 50 to 75 psi. Now if the pump you have has both pump sections the same size you there will be probaby be some collection of oil in the diff case as it take a while for the oil to run back to your scavaging inlet, so I would highly recommend that you put an actual sump into the diff housing at its low point to collect the oil for the scavaging section. If your pump happens to have a large section and a smaller section then make the large section the scavenger..
Rex
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When you used the strange 12 bolt drop out, what did you use for a spool? Strange said that they only have a spool for a 4 series gear set.
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Is the Ford 8" rear an option for lower classes ?
Thanks.
Ian
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Is the Ford 8" rear an option for lower classes ?
Thanks.
Ian
I HOPE SO!
Harvey
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The basic rear end is almost finished. No nuts, cherries or whipped cream, vanilla all the way. The axles were swapped, left for right to offset the pinion, giving my rear a little more room.
The drag car I crew broke the timing gear right in half, so we picked up a steel straight cut set. I have used these in the past and they whined like a loser on election day. These came polished and were very quiet. It takes energy to make noise and I'm sure these folks didn't do it for looks. Is there horsepower to be gained from this? Also, where does one find nozzles to spray the oil? I've been considering adding a brace to the bottom of the rear end housing and letting that be my sump. The oil would gravity drain down, away from the gears, be picked up, cooled, filtered and sprayed from there. Sound plausible?
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I used an electric motor to run my dry sump system. Once I calculated the volume I picked up the correct pulleys and some belts and put this together. Still need to build a shroud and mill the shaft down a little. If you add a brace on the bottom to double as your sump wouldn’t that hang down in the air stream? Why not add the brace to the back of the housing where it will do more good and build a small sump? I will try to post some pictures of the sump I built.
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The sump I built looks more like an overgrown hockey puck. Just machine flat the bottom of the housing and make something like this to fit. I used an “o” ring to seal it with a –8 coming off the side. I had Mike at Patterson build me a small tank. He used the same style of baffling that he puts in the off shore race boat dry sump transmission tank. He thought this type of baffling would work better and wont starve the system when the parachute deploys.
As for the nozzles I made mine once I figured out the spray pattern I wanted.
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You sure have some purdy parts there! I did chuckle a bit when I saw your pump assembly. I was just in the shop thinking of a very similar solution. Tho I do think building my own nozzles will be out of the question, too many unknowns. When do you think it will be ready to run?
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Nozzle poss: pressure washer (pick your own spray pattern, but they're much higher pressure than your pump), oil burner, fuel injector.
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I found oil burner nozzles an attractive thought. So looking them up, I found them available in 30 degree and 45 degee sprays, in solid or conical patterns. Flows from fractions up to about 20 GPH. I guess the next step is putting together the pump assembly and seeing how much pressure and flow the 12 volt motor up will put out.
Yes, a sump hanging down in the wind wouldn't be good. If it did, I wouldn't use it. Most of my energy is going into the head and fuel injection system right now anyway. The rear end will work as is.
I still would like to know about micro polishing the gears. I've heard pro's and con's but not enough facts.
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the gph rating of oil burner nozzles is at 100 psi, so you might want to start with a bigger nozzle than you think. the copper mesh on the back side of the nozzle is strainer that stops easily, but can be removed.
good luck
robbie
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I would not micro polish gears, it makes absolutely no senesce. If you look at the face of gears they ride in valleys and peaks. When the gears are micro polished or REM finished, those valleys and peaks are eliminated. All you end up with is more friction and heat. Its far better to take them to a good shot peen shop and get them done.
When I tested the different rear ends on the chassis dyno there was enough of a measurable difference between the shot peen and the micro polish gears that I wouldn’t want to run the polished or REM gears. Micro polishing is good if you can get a Ra1 or better finish for DLC coating. The only people that I hear running micro polished gears is NASCAR guys, then again they use bajo fittings on their dry sump pans to help flow. Hmm Hmm. Maybe this is why there is only about 10 cars on a given Sunday that has a good shot of winning, the rest are grid fillers.
Maybe one of the engineers on the board will chime in on this.
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Yes, if your pump won't produce 100 psi, IIRC flow through an orifice ~ square root of (new press ÷ old press), so if you have 45 psi the new flow rate is 67%, so use the inverse or 149% of the nominal size to get the actual flow at 45 psi. If you have 60 psi: 129%, etc.
Shur-flo makes a nice small 45 psi 1 gpm 12 volt electric pump with iso mounts.
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Another area is the gear oil itself. Run the lightest you can get away with and also the smallest amount. . . . . they normally ran 2 qts of 140 wt in it, they checked the temp one time after a run and it was over 250 deg F! so they next run they put in one qt of ATF,
No heat and they ran 8 or 9 mph faster and a couple of tenths quicker. So there is power in the diff.
Rex
I like the idea of running ATF in the diff, and I know the I/PRO Subaru Justy used it in the transaxle, but don't some ATF's lubricate better than others? I'm not familiar enough with ATF to risk a rear end on the wrong formulation. Would a light deisel grade motor oil (5w30) be a better compromise?
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We ran ATF in our sedan car road racing in SCCA. We would run all weekend in practice, qualifying and the 20 minute race. No wear problems. Regular rear axle with hypoid gears. I know... top speed was only in the low 100s.
Geo
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Someone mentioned the 8 inch ford rearend. it woould be fine for the lower classes up to about 300hp for drag racing. I ran a 311hp 200 cubic in 6 cyl. in a 66 Mustang coupe and never tore the rearend up. raped the C-3 trans then went to a full C-4.
There are some shops that do posi units for the 8 inch. I am going to keep the 8in. in my Mercury unless I destroy it. since there is less shock with 3:00 to 1 gears I dont think HP will be that big of a problem with 400 HP since its not being launched like a drag car.
John
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According to Beaver at Winters QuickChange rear ends, " you don't need no stinkin rear end pump to run five miles, unless you want one more do-dad to chance screwing up".........Bob, who spent three grand there and was talked out of a pump.................
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According to Beaver at Winters QuickChange rear ends, " you don't need no stinkin rear end pump to run five miles, unless you want one more do-dad to chance screwing up".........Bob, who spent three grand there and was talked out of a pump.................
Bob What did Beaver recomend for oil in our situation? I put TDH ( transmission,differential,hydralic) oil in my Muncie and my Winters quick change at speedweek.
My first pass the car started slowing at the 4 mile. By the time I got to the return road the car would not even roll. Turns out 1st gear became one with the mainshaft in the trans.
I did some percision machine work with a Makita grinder ( ground off all the teeth on first gear) and kept running. I put 85w 90 in the rear before I made any more passes as I did not think I had any extra gears to grind on in the rear and did not want to take any chances. That said I did not see any problems with the rear and would like to try some lighter oil again.
The trans shop I bought my new Muncie parts from recomended 50w in the trans. This is standard OP in Roadrangers ( big truck transmissions) but as I said above I am a little gun shy at this point. Thanks Vince
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Beaver recomended I run their standard gear oil, which of course doesn't give you any info on the label........go figure. I think we could probably get away with something lighter than 90 weight as long as it is a "climing gear lube" that is available from Speedway Motors and most roundy round suppliers. I had some circle track friends try Red Line synthetic in their Q.C. and it did not like it, but they are under a lot more load and for a much longer time.......You might call Joe Timey at Delaware Chassis and see what he thinks, he is a dealer for Winters.............Bob
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Vince,
I would not try lighter gear lube in the rear. I use 75W/90 Amsoil in all of my rears. I installed sensors in a couple of 240 mph cars and only saw a small temp increase. The most important thing is to NOT overfill the rear.
joe