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pro mod build info.


comp1839

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for you guys building pro mod's or any fast door car. there are 2 really good builds going on at yellow bullet. one is a big tire outlaw car by precision chassis:

http://www.yellowbullet.com/forum/showthread.php?t=599288

and the other is a pro mod by tim mcamis race cars:

http://www.yellowbullet.com/forum/showthread.php?t=600464

both are literally packed with excellent step by step pictures. VERY close up and well detailed. the info here is PRICELESS!

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Man i tell you that is just great stuff really appreciate the info you have supplied us with it is so well presented and detailed it will help out lots and lots and the best psrt is you can mix and match and come up with your own ideas the sites are awsome . Pro Mod/Top Doorslamers just cant get enought .One day i am going to score a burnout in one as i know a few guys here thanks mate lol.

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Great reference links for adding accurate detail - thanks Dave.

I never noticed the chassis bolting to the rear engine plate. Is it normal for this class and how about other classes?

tz5l.jpg

From t he revised 2013 NHRA rule book:

“Where an SFI 6.1, 6.3, or 9.1 bellhousing is mandatory, a full, onepiece

motor plate is also mandatory at the rear of the engine block.

The motor plate must be constructed of steel or 6061-T6, 7075-T6

or 2024-T3 wrought heat-treated aluminum alloy plate, minimum

1/8-inch thick for 6.1 or 9.1 applications, minimum 3/16-inch thick

for 6.3 applications. In addition to the fastener requirements noted

below, the SFI 6.3 flywheel shield must be fastened to the motor

plate with four 1/2-inch-diameter Grade 5 shoulder bolts or high

strength steel (or titanium) fasteners and nuts…”

Dragsters, Funny Cars, Competition Eliminator, Pro-Mod, Top Sportsmen probably Pro Stock.

All V8 cars with a clutch are required to have an SFI 6.1 rated transmission shield. I don't think that's a bell housing.

Dale
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guys you're very welcome. i'm glad to help.

ted, it is normal for the mid plate to bolt to the chassis in all cars using a mid plate. it's actually mandatory i believe.

dale, i really admire your enthusiasm. you should take your time and read this stuff. the part you're stating is for clutch cars. 6.1, 6.2, 6.3 and 9.1 are all sfi certs, for bell housings. not transmissions. the reference to the four 1/2" grade 5 bolts are actually four extra bolts required to bolt the bellhousing to the mid plate. these bolts do not have anything to do with mounting the mid plate to the frame. i believe four 3/8" bolts are required to bolt the plate to the frame. requirements for t/f dragsters and funny cars differ greatly from pro mod, pro stock, comp, and sportsman classes.

you'll note there is an automatic in the car. that requires an sfi 29.1 flex plate and a 30.1 flex plate sheild. the trans requires a 4.1 transmission shield. in pro mod converter drives are required to have a 6.1 or 6.3 clutch can and a 29.1 flexplate.

most of this is probably useless info to most of you. unless you are detailed oriented enough to put the appropriate sfi stickers on the components.

here is a clutch can. note the four "ears" and the extra bolt holes they provide.

Titaniumbellhousing.jpg

here is a converter drive(a bruno unit) with a clutch can. pro mod required.

025.jpg

here is the same drive before with a 30.1 sheild ( the front bell is actually the cert'd sheild.) sportsman required.

03213_zps55ecbbc5.jpg

if you have any questions please ask. my only goal is make sure you get accurate information, not to step on toes or hurt feelings.

Edited by comp1839
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guys you're very welcome. i'm glad to help.

ted, it is normal for the mid plate to bolt to the chassis in all cars using a mid plate. it's actually mandatory i believe.

dale, i really admire your enthusiasm. you should take your time and read this stuff. the part you're stating is for clutch cars. 6.1, 6.2, 6.3 and 9.1 are all sfi certs, for bell housings. not transmissions. the reference to the four 1/2" grade 5 bolts are actually four extra bolts required to bolt the bellhousing to the mid plate. these bolts do not have anything to do with mounting the mid plate to the frame. i believe four 3/8" bolts are required to bolt the plate to the frame. requirements for t/f dragsters and funny cars differ greatly from pro mod, pro stock, comp, and sportsman classes.

you'll note there is an automatic in the car. that requires an sfi 29.1 flex plate and a 30.1 flex plate sheild. the trans requires a 4.1 transmission shield. in pro mod converter drives are required to have a 6.1 or 6.3 clutch can and a 29.1 flexplate.

most of this is probably useless info to most of you. unless you are detailed oriented enough to put the appropriate sfi stickers on the components.

here is a clutch can. note the four "ears" and the extra bolt holes they provide.

Titaniumbellhousing.jpg

here is a converter drive(a bruno unit) with a clutch can. pro mod required.

025.jpg

here is the same drive before with a 30.1 sheild ( the front bell is actually the cert'd sheild.) sportsman required.

03213_zps55ecbbc5.jpg

if you have any questions please ask. my only goal is make sure you get accurate information, not to step on toes or hurt feelings.

No problem. The question I replied to concerned the motor mount bolted to the chassis between the bell housing and motor. I interpreted my cursory reading as "If you have to have this type of bell housing, you need this motor mount". Probably wrong. I think that type of plate also serves as a firewall in tube chassis cars.

Dale

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the nhra rule book is not always the easiest to interpret dale. the "motor plate they are referring to is not the motor mounting plate that is being referenced in the pic that ted posted. it is referring to what is commonly called the "block saver plate" which is mandatory with ALL of these bellhousings. the mid plate (motor mounting plate) which you see in the picture can be used in lieu of the block saver plate but, a mid plate is not mandatory with a clutch can. see the difference?

and yes the mid plate can serve as PART of the fire wall. although again, it does not have to be part of the firewall.

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here is a clutch can. note the four "ears" and the extra bolt holes they provide.

Titaniumbellhousing.jpg

thanks for the links. I posed a questions a while back on modernizing the "pro sportsman" chassis out in the jukebox ford and the 55 and 57 chevys. this will help!!

now, who does that clutch can in resin?

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to take the discussion a little further about the motor plate being part of the firewall or not. since you guys have seen the two builds going on in the previous threads you'll note both cars have the mid plate tied directly into the firewall. here are 2 cars i took pics of that are not like that. one is my buddy mark's d/a beretta. the other is cunningham's pro stock mustang.

the beretta. note the clutch can is well in front of the firewall.

P1010014j_zps2f9a5796.jpg

inside.

P1010002p_zpsc55408c8.jpg

the pro stock mustang.

068_zpsb2690db0.jpg

inside.

069_zpse7154613.jpg

hopefully the difference between the 2 styles is glaringly different. if not, just ask.

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i can't tell you if this is accurate for your build. there are just too many builder variations that can happen. this is from a pro mod not a pro stock. again this is just one of many possible setups.

precisionshopphotos-doug703_zps1b999c68.

you asked if there plumbed the same way as a street car. well, i can say maybe similar. depends on what you mean exactly when you say that. do you mean the routing of the lines probably not. if you mean the design of the hydraulic system then, yes.

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Thanks for the detailed info Dale and Dave. Here is a better shot of the 'block-saver' plate. Looks like 8 bolts are fastening it to the chassis and according to what Dave said, it looks like this car would have the block saver plate AND a firewall - not having the firewall take the place of it. Is this correct?

dy94.jpg

Dave - What is that solenoid at the bottom of the chassis for? Fire suppression? Looking at the line routing, It would appear to be brakes, but a solenoid is either on or off, not incremental.

n7xp.jpg

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^^^ Line lock?

EDIT: I don't build these things, but here's my observation. The front plate and block saver would serve to contain the block within the chassis in case of a wreck or major explosion. It's the heaviest part of the car and could cause the most destruction if it got away. The angled web of tubing leading away from the rear mount are covered with sheet metal that create the fire wall.

Dale

Edited by ScaleDale
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ted, there are 8 bolts there, like i said, i believe only 4 are mandatory. it looks as though the mid plate will become part of the firewall, yes. here's a pic of my own car. you can see the mid plate is part of the firewall. the mid plate here is attached by 4 bolts.

DSCF1507_zpsa776c41e.jpg

the solenoid is a line lock.

dale, that's an interesting observation. you would need to talk to that chassis builder to find out his reasons for build his chassis that way. i will repeat this again. no 2 chassis builders build a car exactly alike. they have their own reason's, thoughts, and secret stuff they do to their chassis to make it (hopefully ) outperform the other brands. there are basic rules they must abide by in construction for saftey(those would be, what are found, in the sfi manuals and the sanctioning body rulebook) after that it's up to the builder on how he builds the car. some work better than others with certain drivetrain combinations. it's definitely a world of black arts and hidden secrets.

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