Mastersbilt Help

I am struggling to get a grip on this car so any useful, experienced suggestion is appreciated. We are new to Mastersbilt but have run dirt late models for 20+ years. We have a 2010 Mastersbilt Smackdown with the wide right front 5010 model options with S7 spindles. We run a 3/8 mile banked track that is wide and sweeping at one end and has a tight corner on the other end. Starts tacky and the car is very good, by the end of the night it WILL NOT enter the corner with any speed at all. It feels like the car wants to skate especially on RR and we looped it twice on our own last night which has not happened in years. The car is really good from the middle off on throttle but is horrible on entry. I have tried by the book, I have tried suggestions from Masters, I have tried suggestions from Shorty who built the shocks, I have used some things we used to do on our Rockets. Nothing seems to help!

Current Setup:
Wheel Weights:
LF: 540 RF: 485
LR: 675 RR: 575
100 lbs. bite
54.5% left side
54.8% rear

Springs: LF500 ( have gone to 550 no help) RF375 ( have been at 400 before)
LR 200 tried 250 no change RR 225 ( 250 last week, no change)
5th coil-350 at 35 inches
side to side 16 inches

Bars (4holes on chassis)
Left side lengths- LRU- 17 inches- 1 hole down from top RRU- 16.5 inches- 2 holes down
LRB- 15.5 inches- 1 hole up from bottom RRB- 15 inches- bottom hole

I have tried dummy shock and without- no significant change either way
J bar is at 18 3/8 length
2nd hole up on pinion (lower and it lifts LF really bad)
8.5 inches up on frame
LR limiter chain at 13 inches
Ride Heights - LF 3.75 RF 3.5
LR- wedge RR- 6
I moved the angled fuel cell to the right as far as I could to get LS% down to 54.5. It was the the left as far as possible at first. I have tried an aggressive rebound RF package, and a mild shock package, same result.All birdcages and heims are new and are from Masters. Fresh low drag Franklin Rear
Caster and Camber set from Masters Book

When I add any more rake, the car lifts badly on LF. If I soften compression on RR it does the same.
We have a 430 CI aluminum Motor with 825 HP. Bert Ball Spline and Carbon Fiber Shaft. Driver does tend to use go peddle like a switch and prefers the bottom groove. Any suggestions please post or PM. I have never asked for help on here but I thought maybe I am overlooking something. Thanks

We had the same problem with our car but its not a MasterSbilt ,I have had the same problem with it running the same springs you are i flopped the back springs but the 225 lr 200 rr dropped wedge to 60 lbs. and the car has ton side bite getting in now just something to think about. We also had one of those cars 09 and after 15 races the car started cracking around the welds on the rf a- arm area and the lr where your j-bar mounts to the frame .

Just curious, what is an aggressive rebound? Fast, or slow? I would think you would want the rebound slow(higher number) on the right side to keep the weight shift hanging on the right in the slick. What about brake bias? Sticking front right caliper maybe?

Why is only 1 bar at the standard length?

I am sorry, i posted the wrong bar measurements. The left side are both set to standard length from Mastersbilt S7 setup book. The right side was set to book length and this week I shortened them each 1/2 inch to try to tighten entry. When I said aggressive shock I mean rf rebound at full +. So, again my fault in description, I guess no rebound would have been better description for rf.

It sounds like something is preventing the car from getting over on the RR on entry.
I would suggest taking the shocks and springs off and moving all suspension components through all possible ranges of motion. Something could be in a bind. Be sure that at all points of motion in the rear end, you can grab the bars and j-bar and rotate them freely. i.e. grab the bar and turn it like you would to lengthen or shorten it if you had the jam nuts loose. If you can't move it easily, that's bad. If you can't move it all, that's really bad.

we run the same basic car, S7 front, we use alot less left side weight, like 53.6-53.8. had a hard time with entry until I got that left side weight down. Also, we have played around with fuel cells that get the fuel weight out of the tail a bit, that helped the car big time, we run top 3 almost every night since we did these things. We are on a soft rf though, so its a bit of a different setup. Have been running 275Rf with bump stop to cushion

6" right height on RR seems low..

I've always been around 7 1/2".

Does that sound right?

Yep I think the book calls for 7 3/8". Whats your rear end side to side measurement?

The side to side was 15 3/4 up until last week and then I pulled it to 16 to try to tighten up entry.

I didn't notice the 6" ride height until MBRacer pointed it out. That's way off. 7 3/8 is starting point.
Also, the LF ride height is a little high. Should be 3 1/2 baseline.

Let me ask you this...How much shock drop do you have on the RR and what kind of birdcages do you have?

The birdcages are new this season and they are TWM Bearing Cages. I will check the RR shock drop today to be sure. Thanks for your suggestions, I really do appreciate it.

I don't understand your rear ride heights. Your rr should be at 7 3/8 and your lr should be around 7 1/2 to 8 inches depending in wedge. But do not go over 8 inches on the lr!!

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Originally Posted by settler98

I am struggling to get a grip on this car so any useful, experienced suggestion is appreciated. We are new to Mastersbilt but have run dirt late models for 20+ years. We have a 2010 Mastersbilt Smackdown with the wide right front 5010 model options with S7 spindles. We run a 3/8 mile banked track that is wide and sweeping at one end and has a tight corner on the other end. Starts tacky and the car is very good, by the end of the night it WILL NOT enter the corner with any speed at all. It feels like the car wants to skate especially on RR and we looped it twice on our own last night which has not happened in years. The car is really good from the middle off on throttle but is horrible on entry. I have tried by the book, I have tried suggestions from Masters, I have tried suggestions from Shorty who built the shocks, I have used some things we used to do on our Rockets. Nothing seems to help!

Current Setup:
Wheel Weights:
LF: 540 RF: 485
LR: 675 RR: 575
100 lbs. bite
54.5% left side
54.8% rear

Springs: LF500 ( have gone to 550 no help) RF375 ( have been at 400 before)
LR 200 tried 250 no change RR 225 ( 250 last week, no change)
5th coil-350 at 35 inches
side to side 16 inches

Bars (4holes on chassis)
Left side lengths- LRU- 17 inches- 1 hole down from top RRU- 16.5 inches- 2 holes down
LRB- 15.5 inches- 1 hole up from bottom RRB- 15 inches- bottom hole

I have tried dummy shock and without- no significant change either way
J bar is at 18 3/8 length
2nd hole up on pinion (lower and it lifts LF really bad)
8.5 inches up on frame
LR limiter chain at 13 inches
Ride Heights - LF 3.75 RF 3.5
LR- wedge RR- 6
I moved the angled fuel cell to the right as far as I could to get LS% down to 54.5. It was the the left as far as possible at first. I have tried an aggressive rebound RF package, and a mild shock package, same result.All birdcages and heims are new and are from Masters. Fresh low drag Franklin Rear
Caster and Camber set from Masters Book

When I add any more rake, the car lifts badly on LF. If I soften compression on RR it does the same.
We have a 430 CI aluminum Motor with 825 HP. Bert Ball Spline and Carbon Fiber Shaft. Driver does tend to use go peddle like a switch and prefers the bottom groove. Any suggestions please post or PM. I have never asked for help on here but I thought maybe I am overlooking something. Thanks

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Try changing the driver if he has no throttle control !!!

Quote:

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Originally Posted by jedclampit

Try changing the driver if he has no throttle control !!!

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That's advice you don't here very often, but its often the BEST advice !!!!!!!!!

Quote:

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Originally Posted by 01_4_life

That's advice you don't here very often, but its often the BEST advice !!!!!!!!!

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Sometimes, if only for a night, it can let someone see if it's them or the car. Takes a driver with the overall team goal in mind to try. Referred to as 'adjusting the loose nut behind the padded wheel'