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Tech Information => Steering - Suspension - Rear End => Topic started by: TransTurbine on May 10, 2016, 05:30:28 PM

Title: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: TransTurbine on May 10, 2016, 05:30:28 PM
Good day fellow members,

I am currently designing a belly tank style lakester for Bonneville. It will be entered into either the turbine class 1 or 2 category. This will be my first vehicle of this style and environment. With this being said I am relying heavily on other racers and builders with experience.

I am currently working on picking a rear end setup. I am going to go with a quick change setup. I can use a closed tube or open tube live axle setup. Both have pros and cons. However I have one major concern as of now.

I have been told that cars with a short wheel base at Bonneville can be problematic if they do not have a differential. I was told if the rear end starts to come out from underneath me the wheels will then be rotating at different speeds. The differential would accommodate for the inconsistency and hopefully equalize if I kept a straight course.

Does any one have any experience in this area. I would prefer to run a live axle setup yet it will be a closed spool, no differentials are available. Yet do not want to jeopardize my safety.

Any advice would greatly be appreciated.

Seth
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: SPARKY on May 10, 2016, 06:39:25 PM
 :?   What--- just thinking about this you have jeopardized your safety---
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: TransTurbine on May 10, 2016, 06:51:57 PM
Sparky,

Do you have any experience to contribute or recommendations? Have you run a closed spool or know anyone who has? If so what has the experience been?

Thank you,

Seth
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: RichFox on May 10, 2016, 06:56:17 PM
I have run a spool in  roadster. It worked OK. I think I like an open rear end better. You are aware that as a turbine powered car you will be in the streamliner class? I think.
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: Stan Back on May 10, 2016, 07:00:31 PM
It's like Hillary and Donald -- Both can cause trouble.
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: Speed Limit 1000 on May 10, 2016, 07:06:57 PM
We run a lakester with small motors and have a solid rear axle. Most of the time it is fine. Fastest pass H/BGL 246. Put 6 of us in the 200 MPH club. What is the weight? How fast do you want to go? Do you have a SCTA rule book? It can be really fun.

John
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: mike f on May 10, 2016, 08:13:33 PM
Hi to all,  All the cars that have I changed from a spool or locker to a torque bias type differential have gone faster and the drivers have said it was easier to drive.  I like the Eaton Detroit Tru/Track diff. it is a geared type like the high dollar Gleason Torsen diff.  But unlike the Gleason the Tru/Track can have the break away torque set. I know cost is always a factor , but I do not like any geared diff. that uses aluminum cases.  I know I'm an old school guy and believe drive feel is really important and if they can drive it, they will go faster.  Hope this helps.  Mike
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: kiwi belly tank on May 11, 2016, 12:58:47 AM
Either system works fine in light weight tanks & by the way, most tank people hate the term "tanker".
I think Rich is right about the liner class, you might want to clarify that with SCTA.
  Sid.
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: Seldom Seen Slim on May 11, 2016, 08:05:49 AM
TT, how 'bout contacting Joe Timney at Delaware Chassis Works?  He's in Townsend, Delaware - and is - - ah, experienced at the salt.  He might be a good "local" resource for you.  On this Forum he's Joe Timney (search for him).
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: SPARKY on May 11, 2016, 10:50:37 AM
T-T  I have run them all.  I am with Mike F---We run a 7.5" GM rear with a Toreson with 2.14  at B'Ville  a we are trying a 2.73 at El M this weekend we run a PG without a TQ converter with GV .78 as a 3 speed we do not use it in low---maybe some day we will get brave enough

This comb is very pocket book friendly---thanks to Ebay---be ware GM did a lousy job on the axle tubes---they are not parallel to one another--some are horrible  my best luck is out of M vans,  be sure to use an alignment bar that goes all the way through and put the end on first that has the lowest deviation.
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: TransTurbine on May 11, 2016, 01:15:24 PM
Good afternoon Fellow Members,

I truly appreciate all the replies and information. I have a new rule book coming and look forward to getting acclimated to the contents. I will certainly have to find out if I can run a Belly tank style vehicle. I believe I can since that class is weight based yet I will know more soon. I would be entering into either class 1 or 2. Class 2 is 1100-2200 lbs and current speed is 240 plus mph. Class 1 would be below 1099lbs and current record is 223.464 mph. If my final weight is low enough I would be going for T1.

I would really like to use an open tube quick change from winters since it gives me flexibility with brake placement and slide on wheel hubs, etc. I can run inboard calipers and rotors which will sit on either side of the rear and be enclosed within the body. Down side is the highest ratio available is 2.19.

I can go with a closed tube winter's quick change and get a ratio of 1.80 which will certainly help with my speed class. Down side is the extra weight and outboard rotors and calipers. I would prefer to have everything simple and streamlined. With a closed tube I can also install a differential.
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: Peter Jack on May 11, 2016, 01:27:55 PM
What's this class 1 or class 2 you're talking about? Those sure don't sound like SCTA classes. It sounds like you're talking maybe FIA which is a totally different thing and you're looking at totally different events.

Pete
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: SPARKY on May 11, 2016, 02:31:20 PM
what kind of tranny--if any---what shaft speed will you be working with?
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: Glen on May 11, 2016, 02:34:52 PM
PJ, the rule book on turbine cars has any body configuration, not restricted to streamliners.
class 1under 1099 lbs.
class 2 1100 to 2200 lbs.
class 3 2201 and over
The records for each class is listed, however I believe the FIA is different.
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: TransTurbine on May 11, 2016, 02:54:35 PM
Yes they are indeed SCTA Classes. I would not be using any transmission. The Gas turbine is a turboshaft with free turbine power section. No transmission is needed. The quick change rear will mount right up to the bell housing on the turbine. At 100 percent the turbine's output shaft will be 6000 rpm. I plan on using 17" wheels with tires with an OD of approximately 26" as long as M/H tires will be acceptable. That is a topic for another day. Based on these parameters with a rear end ratio of 2.19, I will have a potential top speed of 212 mph. This speed would certainly not break any records. This gear ratio is the highest I can go with an open tube rear. Now I can switch over to a closed tube quick change rear and get a 1.80 ratio which would get me to a potential speed of 257.90 mph which is indeed capable of setting a new record. I would like to build the car with record breaking capability however this will be my first time driving at Bonneville and I am mainly interested in the learning experience and build. Certainly a 200 plus mph run would be a great accomplishment. I would love any suggestions of a rear that could get me into a higher ratio than the proposed 1.80. I am not set on a quick change, yet the convenience to change ratios sounds nice. As always any suggestions or feedback would greatly be appreciated.
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: jl222 on May 11, 2016, 03:20:27 PM
 A Gearvendor overdrive unit would help. But not sure how much room You have.

         jl222 :cheers:
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: Peter Jack on May 11, 2016, 04:04:01 PM
Thanks Glen. Now I see what you're talking about.  :-D :-D :-D

Pete
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: Glen on May 11, 2016, 04:30:32 PM
JL222 on the Turbinator II we have a gear reduction drive to reduce the engine speed by 1/2 , 19000 rpm was a little more then we could handle. I will be interested in this build though.
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: Jack Gifford on May 12, 2016, 12:53:40 AM
Is the 2.19 ratio of the open tube QC the ring/pinion ratio? If so, you'd have the freedom to set whatever overall ratio you want, via the QC gearset.
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: jl222 on May 12, 2016, 01:16:57 AM
JL222 on the Turbinator II we have a gear reduction drive to reduce the engine speed by 1/2 , 19000 rpm was a little more then we could handle. I will be interested in this build though.


 I was surprised that his output speed is only 6000 rpm. I thought all turbines were faster.

 Stop by if your at El Mirage.

    JL222
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: TransTurbine on May 12, 2016, 02:17:19 PM
The gas and power turbines spin close to 40,000 rpm. The free power turbine goes in a planetary reduction gearbox providing the final 6000 rpm. The 2.19 is not the ring and pinion ratio, it would be the final overall ratio with a specific quick change gear set installed. 2.19 is the highest I can go with an open tube, live axle, quick change setup.

This is really tipping the scale in favor of a closed tube quick change where I can go with a final ratio of 1.80 since type can accommodate a smaller ring and pinion. It is just those outboard mounted rotors and calipers that I don't like much. If I wanted to space my rear off from my turbine, I could use a short shaft and install my breaking before the rear end. However This just adds more complexity and more moving parts to the equation as well as additional weight.

With this being said I will stick to the rear end being mounted directly to the turbine. My next topic I am looking for feedback on is suspension vs. rigid. However I will leave this for a separate post. Also will wait for my rule book before popping off tons of questions that can probably be answered there.
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: bbarn on May 12, 2016, 02:56:43 PM
I plan on using 17" wheels with tires with an OD of approximately 26" as long as M/H tires will be acceptable. That is a topic for another day.

I would recommend not waiting too long into your design (pre-build) stage to decide on a wheel and tire combination. I didn't catch a speed that you are shooting for but tires can become the center of all your woes very quickly.

Ground clearance, turn radius, brake design, suspension travel, clearances, room for growth...all these things (AND MORE) can be determined or limited or prevented by the tires you choose.

Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: Rex Schimmer on May 12, 2016, 03:23:17 PM
Many times the maximum ratio for a QC is limited by the diameter that the case is bored to to clear the change gears. What can be done is to bore the case to accept the larger diameter change gears. Could be that the live axle model that you are considering, which is predominately used in dirt cars, cannot take a larger gear on the lower shaft because the case bore is to small. I would check with your potential supplier and see if that is the problem and if they could bore it larger.

Rex
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: TransTurbine on May 12, 2016, 03:31:58 PM
Alright let is now talk some tires. I am planning on using 17" solid aluminum wheels. This limits my tire options. I can choose Goodyear Eagle Front Runners which only have an OD of 22" which would net me 218 mph. That speed will not achieve a new record in class 1 or class 2. So that points me to a taller tire, which brings me to the manufacturer of M/H which has a 26" and 28" OD tires for the 17" wheel.

Now, I am open to using a 15" wheel which would open me back up to more options with goodyear. I have had a hard time finding a solid 15" wheel which is 3.5-4.5" wide. I prefer not to run a spoked wheel or moon covers. I like the moon look yet much rather achieve it with a solid wheel.

Any suggestions would absolutely be appreciated!

Seth
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: SPARKY on May 12, 2016, 03:33:00 PM
My final drive is 1.66 with 2.14 and a 22% od from the GV( which is very small and can be set up to free wheel)   with 24.5 tires has ben 309 at 6900
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: jacksoni on May 12, 2016, 08:04:59 PM
In your post # 20 above you mention a "problem" of extra weight. As you are in the  traction limited realm of power and speed, weight- properly distributed- is your friend. Lots of post about that here. Don't worry about that one.

You might look at, if have not seen already, this thread: http://www.landracing.com/forum/index.php/topic,15803.0.html Similar questions being addressed. There are a lot of lakester build threads on here, be worthwhile to read them all.

Also some comments about suspension in this thread: http://www.landracing.com/forum/index.php/topic,15841.0.html
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: bbarn on May 13, 2016, 10:28:11 AM
Alright let is now talk some tires. I am planning on using 17" solid aluminum wheels. This limits my tire options. I can choose Goodyear Eagle Front Runners which only have an OD of 22" which would net me 218 mph. That speed will not achieve a new record in class 1 or class 2. So that points me to a taller tire, which brings me to the manufacturer of M/H which has a 26" and 28" OD tires for the 17" wheel.

Now, I am open to using a 15" wheel which would open me back up to more options with goodyear. I have had a hard time finding a solid 15" wheel which is 3.5-4.5" wide. I prefer not to run a spoked wheel or moon covers. I like the moon look yet much rather achieve it with a solid wheel.

Any suggestions would absolutely be appreciated!

Seth

Custom wheels aren't a bad way to go here. If you have solid centers there isn't a lot of machining required to make them which keeps them extremely reasonable.

We did customs for ours which let us design the width and the offset we required for packaging. The prices were very reasonable.
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: Rex Schimmer on May 13, 2016, 01:21:41 PM
Seth,
You said: "Alright let is now talk some tires. I am planning on using 17" solid aluminum wheels. This limits my tire options. I can choose Goodyear Eagle Front Runners which only have an OD of 22" which would net me 218 mph." I don't think the Goodyear 17 inch front runners are approved for a drive application, especially the early ones that are limited by the SCTA for front only applications, 200 mph max. The later design tires are rated at 300 mph again for front applications only. Also if you do happen to run these as front tires they have a motorcycle type of bead and require the wheel to have a compatible rim design. (Ask Sparky about this!) If you do plan to run them there is a manufacture in the LA area that makes a forged aluminum solid center wheel with the proper motorcycle bead design that are very reasonable. allamericanwheel.com I have a set and they are nice pieces. Lots of material on the center disc to machine almost any mounting configuration.

Rex
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: Stainless1 on May 21, 2016, 09:08:36 AM
You are limiting your speed potential by building a belly tank lakester for turbine, it was mentioned earlier, you need to pay attention to that.  It takes a lot more HP to run an open wheel vehicle. 
What kind of HP are you planning...
Streamliners get 5 miles, lakesters have to qualify to get more than 3.
Your tire strategy will not work as also mentioned earlier, rethink it. 
Before you build, come to the salt to see how others build.  You probably won't see a lot of turbine cars, but powerplant is a choice, car types and how people package will be what you need to look at.
Good luck with your project, we look forward to more info  :cheers:
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: krusty on May 23, 2016, 04:53:25 PM
Just spitballin'.  If your rear wheel was a 4.5" width and had a 4" backspace (with a 1/2" center) you would have a "flush" exterior and plenty of room to fit in a 2"drum brake with 2" shoes and be able to run an inner wheel disc too. I haven't drawn this out to verify the #s, but you get the idea. Then you could run the the quickchange with the better r&p and the 15" wheels. The drum brakes will provide all the braking  you might need, and can be backed off a skosh :-D to eliminate any drag (just remember to pump them when you first apply them to take up the slack).

vic
Title: Re: Short Wheel Base Belly Tanker at Bonneville: Closed Spool or Differential?
Post by: bbarn on May 24, 2016, 10:51:55 AM
You are limiting your speed potential by building a belly tank lakester for turbine, it was mentioned earlier, you need to pay attention to that.  It takes a lot more HP to run an open wheel vehicle. 
What kind of HP are you planning...
Streamliners get 5 miles, lakesters have to qualify to get more than 3.
Your tire strategy will not work as also mentioned earlier, rethink it. 
Before you build, come to the salt to see how others build.  You probably won't see a lot of turbine cars, but powerplant is a choice, car types and how people package will be what you need to look at.
Good luck with your project, we look forward to more info  :cheers:

I'm with stainless here. Building a liner over a lakester gives you way more options and way better control over your aero package. Unless there is some other reason you are going after the lakester class...perhaps an open record in omega there?