LegendsRacer - Legends & Bandolero Racing Forum
BANDOLEROS => Drivetrain & Gearing => Topic started by: jcbowen on May 23, 2011, 09:04:58 pm
-
My son and I are new to bando racing. We have a team that has three cars and they are beating us by 3-4 seconds a lap. I know there are tricks to the trade but there cars are way fast. Any suggestions?
-
What size track(s) are you running?
What is your current gearing?
Steve
-
.395 track. Running a 55 rear sprocket and a factory cluch sprocket. Have a feeling thats where we are getting beat.
-
How many teeth on the sprocket?
Steve
-
14/55
-
That would give you an overall ratio of 3.93. Too high. Thinking you should try something like 13/63 which is about 4.85. If all you have is the 14 tooth clutch, then perhaps something like 14/68 which gives you an overall ratio of 4.86.
Steve
-
Are you running a restrictor plate ( if so, red or blue); what RPM are you turning; what degree of banking do the corners have?
-
Good point Mike, I wasn't thinking about restrictor plates.
James,
Not sure as to the rest of your set up, but it looks like your number 1 problem is the gearing. Kind of like running a highway gear at a drag strip.
I am doubtful that you are getting anywhere near the rev limiter by the end of the straights.
Steve
-
.395 track with 6 degrees in the corners 4 in the straights.Running blue plate.
-
James,
Check this thread and see if it is any help:
http://www.legendsracer.com/index.php?topic=1449.0
or perhaps this one:
http://www.legendsracer.com/index.php?topic=1173.0
Steve
-
Right front caster -3.5 camber +4
left front caster +2 camber +1.5
-
It looks like you're on a roughly .4 mile track (pretty big), with very little banking, on a blue restrictor plate. Your front end numbers look pretty good, but I would change the caster on the left front so it sets in the middle of the adjustment slot. Your current setting on the LF makes the car physically hard to turn, and also scrubs off corner speed.
Provided you don't have a gear rule, I'd run a 15 tooth clutch with a 57, 56 or 55 gear. The blue plate is likely putting out only 10.5- 11 HP if you have only thrown a plate in and gone racing. Blue plate engines (legal ones at least) don't need to turn more than 5,000 RPM. The HP starts to fall off after 4,000-4500 RPM, and really takes a dive after 5K (down to 8.5 -9 HP).
Based upon the many restrictor plate engines I have dyno'd and carbs I have blueprinted and flowed, a good legal blue plate engine can produce 13 -13.5 HP and should race at 5000 RPM running alone on the track. This allows for some increase (roughly 5150 RPM) when in a draft). Red Plates are typically 13-13.5 HP when you just throw the plate in, and good ones with flowed carbs and dyno tuning put out 15.75 - 16.2 HP. You never want to get even close to the chip with a blue or red plate-- there's just no power up there in that RPM range, and you'll just be making RPM but going nowhere. So you could be down 2- 2.5 HP compared to the flowed and dyno'd engines, which may not sound like a big deal, buts it's approximately 20% if you've got 11 HP and your competitors have 13.2 HP!!!
Then there are all the other tricks perculiar to plate racing, ie. toe, stagger, tire pressure, axle lead or lag, aero packages, oils, jetting, air bleeds, etc., etc. etc. All of these things are different from non-plate racing. Plate racing is a separate breed, and the ones who have all the little things in place can look like cheated-up rockets, and still be 100% legal. It is frustrating if you haven't figured out all the "tricks"; but its smooth sailing when you finally get everything right.
Hope I've helped some.
Mike Hudson
-
Are you sure the track in question requires a plate? Many tracks don't. If you have a choice of tracks, race as much as possible on a non-plate track. Driving on a non-plate track will devolop driving skills not used at a many plate tracks.
-
Ed,
I'm curious too as to whether the plate is required at Langley. I tried to check their rules, but found no mention of Bando cars what-so-ever. Typical!
Been trying to get info from James and hope to find out a little bit more from him.
Mike,
Thanks for the input! When I heard he was running a plate, I started thinking in a slightly different direction. Working on getting some set up info. If you check the Langley site, he has gained a little. Is still way down on speed and lap times. Engine? Driver? Don't know... We are working on that.
Steve
-
Upon closer review of the caster/camber numbers posted above, I think maybe the caster and camber numbers are reversed. Therefore, I would strike my previous post insofar as it regards changes to the caster. I would suggest the following:
Camber RF 4.5; LF 2 (I always forget which is + and -, but both tires should be leaning to the left, toward the infield)
Caster: RF -- all the way back; LF -- set in the middle of the slot.
Mike.
-
Set up seems way off as far as caster and camber. I am trying to get his complete set up via an email so I can look over where he is at.
No numbers as of yet.
Also trying to get an answer to any experience with racing (Father or Son). Hard to give someone information when you don't know what they do or don't know, or understand.
Thanks for the info and descriptiveness of your reply Mike!
Steve
-
I'm the driver and there is a restricter plate rule and we really need help to get faster
-
It's been over 3 years now since we raced bandos, but I will do my best to recall as much as possible and ask some questions that obtaining the answers is very important.
CASTER - I agree with the previous recommendations for the caster settings ( left side in the middle of the slot and the right pulled all the way back) as they will work at just about every track unless you have really tight corners.
CAMBER - The previous recommendations are the typical baseline and could be proper. However obtaining tire temps as soon as the car comes of the track will tell you whether they are correct or not for your track. Tire temps on bando tires can tell you a great deal as they do provide good information as to what is happening. On the Longacre website they provide a nice tech article about reading tire temps, so I won't go into it here in detail. Read that article and it will help you get your camber and tire pressures correct.
AIR PRESSURE - I didn't see anywhere in your post anything about air pressures that you were running, maybe I missed it, but this can be huge and can vary a fair amount between tracks. Not so much on "non-plate" tracks, but at plate tracks you might be surprised at how much pressure you can run due to the size of the track. Back in 2008 we went down to Friendship Speedway in NC (it was asphalt then, now it's dirt) and we ended up running 30lbs on the left and 40lbs on the right! That was due to the fact that the track was .400 and had very sweeping turns with decent banking and thus grip was never an issue. It made a big difference to speed though due to the reduced HP (just as Mike mentioned) and very little if any braking was needed. This may not work for you at your track,but here again is where the tire temps and your driver can tell you. You also should be checking the air pressures as soon as the car comes off the track to see how much each tire gains as that will help tell you where you will need to set your air pressures at the start.
FUEL PUMP VACCUM LINE - One of the most important items that we found with the restrictor plate was removing one of the vaccum lines from the the fuel pump and attaching it to the rear valve cover. Without doing this the engine would sputter about 3/4ths through a full speed lap. This was due to the fuel pump providing too much fuel to the carb and thus "bogging" down the engine due to the resticted air flow caused by the restrictor plate. If smaller jets could be found for the carb that would have helped some too, but we were never able to find smaller then 92 jets.
Now for the questions:
Due you have any drag between your brake pads and the rotor? If so, we can fix that and that is HUGE!
Do you have the dust seals on your front and rear wheel bearings? If so we need to get rid of them and I can help you free up the bearings
What are your ride heights and what is the cross set at?
Are your tires cut?
What oil are you running in the engine?
What lube are you running on your chain?
What color are the springs in the clutch drum?
Let's start there and I can help you further once I have those answers. You can send me a PM if you like, but I would prefer that you answer here so that I can help others as well
Thanks,
Mick
-
I've already asked dad to provide me with complete set up info. Still have not received the set up info. Doesn't have to post it, but can send in a PM so that I can look it over. As I am not, nor ever been a Bando person, I can only guess based on the numbers that I see.
THANKS Mick for the info!!! That has got to be some of the most helpful info listed in some time. Also appreciate that you would like to help others as well.
Steve
-
This may post twice. Dunno what happened to my first one...
I know Langley is a blue plate track. We raced at ODS on Saturday and someone gave us a flyer for their track. Anyway, I think most of the answers to the original post are here. Gearing is/was clearly the first major issue. Carb jetting may be a factor as well. If they are stock, they are probably not big enough.
Regarding caster/camber, I have some things to look at on our ride! The things above are what I call macro changes. Less obvious is the fine tuning of the chassis. We raced (still racing, actually) quarter midgets. Those cars have way more things you can tweak on. What is really important with those cars, especially the junior restrictor plate classes, getting the drag out of the car is an absolute necessity if you plan on running up front. The driver has to be quiet on the wheel, the racing line has to be good and the chassis has to be free. The older kids have the first parts down. The big advantage there is I always ran less gear than our competitors and the car was simply faster. We could carry a lot more speed into the corners and used big mo to make the passes.
That said, Bandos are low powered race cars and, because we run so little stagger, getting the physical drag out of the car would make a huge difference. Tire scrub, chassis alignment etc. We run at ODS where there is a red plate rule, 14 driver rule (which really dictates what axle gears you can run) and a 25 psi right side max tire pressure. I rejetted the carb and I think that helped. The axle gear is a 53 or 54. I tried the 54 without much effect. We may test again when the motor gets back.
That brings me to my question and I apologize for the book! We are considering having our motor dyno'd for 2 reasons. One, I'd like to run the motor in and 2 I'd like to get the right jets in the car for our plate and rpm range. I see the posts about getting the dyne done. Apart from tuning the carb, is there much more that can be done? I heard about exhaust tuning but 600 tells me that they have seen cery little difference with differnent length exhausts. The only advice is to pull the collectors out as far as legally possible.
For carb flowing, that makes me nervous. I had a conversation with our tech guy and he tells me they see polished intake castings and slight bore modifications. Both illegal. And I certainly don't want that. So what is the advantage that can be gained there? Is sending the motor to a third party better than having 600 dyno it? I don't want to break the bank, but 20% is huge if it's real!
Adam
-
Good call on reducing drag and scrub.
Don't know that you can do much with exhaust tuning. I will have to review the rules... I think it falls under the "As delivered by" clause. Perhaps some may be able to get it through tech. I don't think cheating is the way to fly though.
I think the dyno gives you an idea of where your engine is at. You can try things like jetting changes and perhaps whatever exhaust tuning that is allowed and see what difference it makes in the horsepower. Dyno time costs money too. Guess you would need to figure that into your budget.
I'm still learning on the Bando stuff also. It's been a long 4 years trying to understand why most people don't seem willing to share information. I think that the quality of the racing would improve, and would make it overall safer for the beginners or slower driver. JMHO.
Thank You to all that are contributing to this thread! I am learning a lot of new information as far as the resrictor plate racing.
Steve
-
That brings me to my question and I apologize for the book! We are considering having our motor dyno'd for 2 reasons. One, I'd like to run the motor in and 2 I'd like to get the right jets in the car for our plate and rpm range. I see the posts about getting the dyne done. Apart from tuning the carb, is there much more that can be done? I heard about exhaust tuning but 600 tells me that they have seen cery little difference with differnent length exhausts. The only advice is to pull the collectors out as far as legally possible.
For carb flowing, that makes me nervous. I had a conversation with our tech guy and he tells me they see polished intake castings and slight bore modifications. Both illegal. And I certainly don't want that. So what is the advantage that can be gained there? Is sending the motor to a third party better than having 600 dyno it? I don't want to break the bank, but 20% is huge if it's real
THere is more to dyno tuning than the carb. 600 may be correct in that they see very little difference, but if that difference is .3 HP, and then you gain .2-.3 in the other areas, along with some bigger gains with carb, at the end of the day you have significant HP increases in a 13 HP red plate engine! Its all about getting alot of little things right, and getting the most out of that one particular engine.
Also, 600 dyno's indoors, in a controlled environment ( i.e. temp, humdity, etc. stays fairly stable due to Heating & A/C, possible de-humidifiers, etc. within the building.) Thats not what we race in, and sometimes results differ when you dyno to open atmospheric conditions with the temp at 90 and humidity at 65% for ex., as compared to more controlled conditions.
As for flowing/blueprinting a carb, that does not mean the carb is machined, polished, ground, etc. It means that it is flowed on the flowbench, and then parts are changed, etc. to achieve the maximum air flow. Believe it or not, the way a carb is assembled can affect its airflow. Then the fuel ratio needs to be matched to the airflow for that particular carb. This is fine tuned on the dyno, as the air/fuel ratio needed is determined ultimately by the specific engine's intake runners, heads, volumetric efficiency, etc. It can only be found on a dyno, unless you choose to break engine seals and cheat-up the engine.
All I know for sure is that engines come off the dyno with more power than when they went on. The only exception is when the engine is worn, and the dyno won't do a ring job or a valve job! It will tell you that the engine is a dog and needs to be rebuilt, or that the engine is capable of winning. This is quite substantial in and of itself, since you can now rule out engine as the problem, and concentrate on handling, tires, or other issues. Before you can fix what's wrong with a car, its important to verify all the things that are right, and thus eliminate those items from the list of things you suspect as a problem.
For example, its easy to wear out a set of tires, spend money on gas to the track, pit passes, track rental for testing, etc. trying to find speed, when the problem all along was a weak engine. I like to rule out engine, carb and tires as a problem before I ever get to the track. I can rule gearing out pretty quick with the tach and dyno sheet. That only leaves set-up and driver, so I know where to throw the tool box when at the track!
Just my .02 worth.
-
Any suggestions for settings for charlotte motor shootout track, OUTLAW. Class. The car. And driver total weight 785..