New/Old 2.5 class

kino_fab

KTPA Tech Official
Joined
Aug 19, 2007
Messages
2,244
Over the weekend, a group of guys including my self, sat down and pitched the idea of trying to bring back the old 2.5 class that was around in 2008-09. We discussed and agreed on a set of rules for the class, plus tossed around idea's on getting the class added to the line up at many pulls. The President and Secretary of KOTTPA were also present and said as long as their are trucks to run the class, that they would add the class to their events this season on a trial basis with only a percentage payback of the entry fee's as the payout. Basically being a free class for the event promoters.

The Rules are pretty basic, and with the fuel and air limits, we estimate this to be around an average of 650-700hp class, plus with a few cosmetic rules, we want to try to separate the look of the trucks in the class from the other classes that are out there.

I made a facebook group page for the class.
https://www.facebook.com/groups/840075396052033/ Here you can find a copy of the rules, ask questions, post up their builds, plus in the future you can find events that will host this class.

These rules are here for anyone to use. If they want to add this class to their event or sanctioning body, they are more than welcome to make changes for their event(s), but we are trying to make this a class that will work anywhere and be very affordable for even the average Joe. There are already 2.5 and 2.6 classes that are 1000+hp classes, and a person really can't even tell a difference between the two. Maybe if everyone works together and agree's on these rules and keep the class very limited, then hopefully it will not get out of hand and turn into another wallet class like what is already out there.
 
Fuel requirements, IMO are a bit unnecessary. No need to limit pump size or number of pumps. Limit power with a charger not fuel pump(s) limits. I would change the verbage to read "shelf style intake required" for Cummins. Not a fan of the inability of head work on a Cummins when you can easily on Ford or Chevy. Changing those two things allows 2.6 trucks to drop down more easily or for someone to use 2.5 as a stepping stone to 2.6.
 
probably not gonna happen... gotta draw a line some where. If a person wants to run a class with un limited fueling, then they are more than welcome to run with the 2.5 and 2.6 classes that are out there now.
 
probably not gonna happen... gotta draw a line some where. If a person wants to run a class with un limited fueling, then they are more than welcome to run with the 2.5 and 2.6 classes that are out there now.


Interesting rules, I don't think you are gonna limit the HP to 650HP-700HP.

Why allow stock appearing CP3's but not stock appearing P7100?
 
up here we have 2 orgs both running a "2.5" class, they went back on rules compared to previous years to make it more of a hot street/limiting street class. most trucks in the class are not over 700hp. yes there are more trucks. but the class is boring. the free hooks from the local street class that are available to hook at most pulls is more exciting and the top few street trucks beat the "2.5" trucks. I don't like our local "2.5" rules but these make ours look good. good luck with the class.
 
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Why do you want hanging weight if you're trying to make the trucks look different from other classes?
 
I like them. Seems like a lot of experience went into deciding exactly what is needed to keep everyone competitive.

No limit on turbo shaft size?
 
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I don't have the facebook, but I sure hope they changed the turbo rules from when this class was around before. That is the class that started the "stepped" charger BS. It was just a bore limit, no othe restrictions back then. Ol' Wes Wade made many a folk scratch their head as he thumped em week after week. :D

If dual CP3s aren't allowed, IMO a ppump truck should be able to dominate this class. CP3s have come a long way since when this class was around originally but I still think the single CP3 will struggle to keep up. It's not a volume issue.
 
Here are the rules for those who cannot view them on Face book

2.5 Limited Street Diesel Trucks

1. 8500lb maximum weight limit. All trucks are to be weighed with driver.

2. Weight ballast is permitted. May be in front of the front bumper, no more than 60 inches from the center of the front axle. All front weights must be visible and securely fastened to the weight bracket. No weight box’s, brackets style only. Front weight ballast must be securely fastened to the frame rails, and only have movable weight on it. No batteries, tanks, cells, or any other equipment allowed in front of the front bumper. Ballast is also permitted behind the cab of vehicle. Absolutely no weights inside the cab.

3. Dual rear wheels are allowed, but must be used on unmodified factory or aftermarket positive offset dually style wheels with a maximum width of 7 inches. Factory front dual wheel adapters are permitted, but must also be used with a singe factory or aftermarket positive offset dually style wheel. D.O.T. approved tires only. No cut tires.

4. Factory frame rails only. Must be from a 1 ton or less truck. Boxing and bracing of the frame is permitted.

5. A maximum wheelbase for the class will be 176 inches.

6. Suspension:
Front: Any factory style front suspension is allowed. Must use the style of suspension intended for the frame being used. Any aftermarket components can be used. Leaf spring style front suspensions may use traction/antiwrap bars, and must have safety catch chain/cable/tether with in 1ft of the mounting points. Absolutely no air bags, limit straps, adjustable bump stops, or hydraulic/pneumatic bump stops. Bump stops must not be touching and have plenty of clearance while the added weight is in/on the front weight ballast. No electric power steering. All power steering pumps must be driven by the engine.

Rear: A factory style rear suspension must be used that is intended for the frame being used. Suspension may be blocked/linked solid. Traction/Ladder bars are allowed and must have safety catch chain/cable/tether with in 1ft of the mounting points. All solid blocks/links and traction bars must be bolted in and easily removed. Welding of the attachment brackets to the frame and rear axle is permitted. Rear axle housing may be braced to reduce axle flex. In no way will the hitch be allowed to connect to the rear axle.

7. Hitch: The hitch must be a receiver style hitch and mount solid to the frame rails. No draw bar style hitches. Pulling load must pull from and thru the receiver box/hole. Reinforcements are allowed. All reinforcements must be no farther forward than the center of the rear axle and no higher than the top side of the frame rails. No part of the hitch is allow to connect to the rear axle or rear suspension. Hook point must be no less than 48 inches from the center of the rear axle. The hook hole must be at least 3inches wide and 3 ¾inches long. 26” maximum hitch height. All hitch adjusting devices must be connected to the receiver hitch and/or hitch reinforcements. Rear suspension blocks/links maybe used to adjust the hitch height.

8. Engine: Engine must have been and option in a 1 ton or less truck. Maximum 444 cubic inches. No aftermarket blocks or cylinder heads. Cummins heads must have the factory casted intake tunnel on the head. All others must use factory intake manifolds that bolt to the cylinder heads. Aftermarket intake horns and turbo piping is allowed No filled blocks. Coolant must flow thru all factory coolant passages. No electric water pumps. No deck plates. All other internal modifications are permitted.

9. Fueling: All p-pump engines must use a 12mm plunger and an automotive governor. Common Rail engines are limited to 1 stock appearing CP3 injection pump, and factory size housing (i.e. no CP3.4, grand puba, Franken pump, etc…) Injection conversions are allowed (i.e. p-pump 24v, common rail 7.3 power stroke, etc…) Ford 7.3L engines are allowed to run dual HPOP. All injection pumps must be mounted in the factory location for that engine. Any aftermarket supply pump may be used. Fuel cells are allowed, but must be mounted behind the cab. #2 pump diesel fuel only. No additives. No propane, nitrous, or any other compressed gasses.

10. Turbo: Single turbo only. The turbo charger is limited to a 2.5 inch inducer turbo and must maintain this diameter both in front of and behind the MWE groove. T6 exhaust housings are prohibited. Adaptor plates and pedestals may be used. First time and random quick checks will be checked with a 2.55 plug. Compressor wheel is limited to a maximum 99mm exducer. An un-modified, factory style compressor cover must be use (i.e-No Race covers).The MWE groove must remain in the factory location and can be no larger than 0.200” at any point. Bushing of the inducer bore is prohibited. No stepped covers or stepped wheels. Wheel must protrude into the inducer bore and contour back into the exducer area of the compressor cover. 6.4L Power Stroke engines may utilize the factory compound turbo configuration in OEM stock form only(2.6" atmosphere inducer. If at any time the quick plug check is found illegal, or under protest, the compressor cover can be removed to measure the compressor wheel dimensions. The puller or crew member will be responsible for removing the compressor cover.

11. Air to Air intercoolers only. No water injection or water/meth. No spray bars or any other charge air cooling agents are allowed while the vehicle is on the track.

12-A. Manual transmission: Any manual transmission from a 1-ton or less truck is allowed. Up to a 3 disk, conventional style clutch. No Glide style clutches. Aftermarket bell housings are allowed and must be SFI approved. Any truck using a non SFI approved bell housing must use a SFI approved bell housing blanket.

12-B. Automatic Transmission: Any automatic transmission from a 1 ton or less truck is allowed. Must use a torque converter. No clutch setups allowed with automatic transmissions. All other aftermarket components are allowed.

13. Transfer case: Any transfer case from a 1 ton or less truck is allowed. All internal modifications are allowed.

14. Drive Shafts: After market drive shafts and U-joint yokes are allowed. All U-joints must be covered by a minimum 4” wide, 1/8” steel or ¼ ” aluminum shield, 360 degree’s around the u-joint.

15. Axles: Must be an option in a 1 ton or less truck. All aftermarket components are allowed. Bracing of the axle housing is allowed to reduce flex.

16. A full interior is mandatory. Must have full length factory dash, 2 upholstered seats, door panels, and any/all street equipment. No cutting or gutting inside of the cab.

17. Exhaust must exit rearward of the cab and exit up or down. Must have two bolts, 3/8” in a cross pattern within 4ft of the turbo.

18. A kill switch and/or air shut off is mandatory inside the cab and at the rear of truck near the hitch for the sled. All Mechanical injected vehicles must have an air shut off. Electronic injected vehicles Must have either an electric kill switch or air shut off, or both.
 
I've said this for years. Why limit fuel when you limit air? Is your air rules not good enough so you think trying to limit fuel will help? No, I have about 1300 In a dual cp3 setup. I can go spend stupid amounts of money on a single cp3 to flow/jack up pressure. Might not live long and trash a fuel system but if someone wants to dominate and win that's what they will do. Let someone run 10 cp3's and a 14 mm p-pump if they want. If your TURBO rules are good enough you will be able to limit hp to what ever you want it to be. I don't have FB. On edit: Like the idea. I would like to weekend pull in something like this. IMHO its just going to be another outa control class though
 
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I've said this for years. Why limit fuel when you limit air? Is your air rules not good enough so you think trying to limit fuel will help? No, I have about 1300 In a dual cp3 setup. I can go spend stupid amounts of money on a single cp3 to flow/jack up pressure. Might not live long and trash a fuel system but if someone wants to dominate and win that's what they will do. Let someone run 10 cp3's and a 14 mm p-pump if they want. If your TURBO rules are good enough you will be able to limit hp to what ever you want it to be. I don't have FB. On edit: Like the idea. I would like to weekend pull in something like this. IMHO its just going to be another outa control class though

I don't have a dog in this fight....but I agree. Limiting CRs to 1 cp3 is just forcing them to spend more money. I can tell you from experience 3 stock cp3s won't out flow a maxed out 13mm p pump. Who cares how fuel they use.
 
How are you going to police 12mm p-pumps, random removal of fuel lines and pulling DV holders?
 
Probably wouldn't be a random thing. Just under protest or if who ever is putting on the event want to check the 1st place or top 3 or 5 trucks... it's up to them. Wouldn't take 5 minutes to check using a plug gauge. Make the plug 12.5mm so that if it is legal it will not go in, or if it is too big, then it wouldn't be tight enough to cause any damage. Just who ever is doing the check would want to make sure the plug is clean, doesn't have any burrs, and have it lubed with WD40 or similar.
 
You're asking for opinions and we're trying to give you them. If you want a "different" "2.5" class than your common 2.5 purpose built just change them to no hanging weights and factory appearing charger. Limiting fuel is a waste of time and energy. Air is what everyone uses to limit power, why try to impose even more rules? You have to make it realtively straightforward and also attractive to potential trucks. When you say no dual CP3's you're almost instantly eliminating anyone with a newer Dodge or Chevy who would be interested. Since real 2.5 uses purpose built S400's predominantly, start by imposing rules against them. You want less power, restrict them to factory style chargers. You're not going to make a reliable 700+ on a Cheetah...
 
I never asked for anyone's opinions. I was just making the post to let people know about the class that would be interested. The Stock appearing turbo BS has been done before in the past and was just a big mess. As for limiting fuel, everyone here knows that the reason for multiple CP3's and 13mm p-pumps has nothing to do with the amount of fuel they can flow, It is the capabilities of turning higher RPM. Although with the charger limits that we have will limit the RPM any ways, so there really wouldn't even be a need to allow unlimited fueling. Just trying to keep the cost down... Yes A person could spend "Stupid amounts of money" on multiple parts and systems in this class, but honestly the one's that do will not have much of an advantage over the next guy that has no more than $10K in their entire truck.

Like I said, I didn't post this to ask for opinions. And I'm not going to continue arguing over this. This is how all of the other classes got out of hand so fast. A few people make claims that they can't compete with other setups or would have to spend more money for different reasons, so the rules get opened up more and more Every year and more loop holes get created. It's been this way for years and in more than just the diesel classes. The only thing that gets accomplished is the fact that every class becomes competition for who has the most money and makes the sled guy add more weight and more gear. Yes, eventually this class will probably get out of hand just like the others, but it can be prevented or at least take longer to do if everyone will keep the class as limited as possible and not allow the rules to be opened up.
 
It looks good to me. I might add that brakes are mandatory on all wheels and must use the factory style rear suspension with a minimum of two inch travel. The idea of a fun street class is good. The air to water intercoolers, stripped interiors, and hood stacks is where the things went wrong with the other classes.
 
I never asked for anyone's opinions. I was just making the post to let people know about the class that would be interested. The Stock appearing turbo BS has been done before in the past and was just a big mess. As for limiting fuel, everyone here knows that the reason for multiple CP3's and 13mm p-pumps has nothing to do with the amount of fuel they can flow, It is the capabilities of turning higher RPM. Although with the charger limits that we have will limit the RPM any ways, so there really wouldn't even be a need to allow unlimited fueling. Just trying to keep the cost down... Yes A person could spend "Stupid amounts of money" on multiple parts and systems in this class, but honestly the one's that do will not have much of an advantage over the next guy that has no more than $10K in their entire truck.

Like I said, I didn't post this to ask for opinions. And I'm not going to continue arguing over this. This is how all of the other classes got out of hand so fast. A few people make claims that they can't compete with other setups or would have to spend more money for different reasons, so the rules get opened up more and more Every year and more loop holes get created. It's been this way for years and in more than just the diesel classes. The only thing that gets accomplished is the fact that every class becomes competition for who has the most money and makes the sled guy add more weight and more gear. Yes, eventually this class will probably get out of hand just like the others, but it can be prevented or at least take longer to do if everyone will keep the class as limited as possible and not allow the rules to be opened up.

Uuummm no!!! The reason I went with 2 cp3's was to gain rail pressure and volume. I spun my stock cp3 2.5 turbo truck 4K down the track back in 2008. I just didn't have enough fuel for the turbo. I bolted on the second pump to gain 5k in psi. A single cp3 has never limited me in rpm's. Was it efficient? Prob not. Could I do it? All day long.
 
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