What's the diff between NHRA and IHRA Pro Stock cars? (1 Viewer)
- Thread starter jim
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Buzzz Miller
I believe the IHRA cubic inch limits are still at 826 cubic inches for a hemi style head and 840 cubic inches on the wedge stuff.
Plus the IHRA stuff can have a 5.0 bore space engine, which in turn makes a much larger bore, which in turn allows a larger intake valve and increased air flow. Split carbs allow better placement of the venturi over the intake port and better geometry there.
Then everything else stems from that. The chassis are more rigid to overcome the increased torque. longer spoiler by 2" (If I am remembering correctly. doing this off the top of my head.) And 10" longer wheelie bars. The clutches are different obviously, and the transmissions as well.
Without getting too technical, that is about it.
Plus the IHRA stuff can have a 5.0 bore space engine, which in turn makes a much larger bore, which in turn allows a larger intake valve and increased air flow. Split carbs allow better placement of the venturi over the intake port and better geometry there.
Then everything else stems from that. The chassis are more rigid to overcome the increased torque. longer spoiler by 2" (If I am remembering correctly. doing this off the top of my head.) And 10" longer wheelie bars. The clutches are different obviously, and the transmissions as well.
Without getting too technical, that is about it.
Agreed. Throw Ford into the mix and it makes for alot of ford vs. chev vs. dodge(albeit only 1 dodge) racing. Should be exciting this weekend at the rock as I think a few guys have a shot at winning the title at the season ender.
Eric L Williams
Nitro Member
They did great over there!! WJ, Bob Glidden(?), Lee Sheperd, were all world Champs In the IHRA in the eighties. Although the engines were smaller (600-700(?))than they are now, these guy's were players in the moutain motor p/s class!!!! Hell, Lee Sheperd won both the NHRA/IHRA titles in the same year(I think). Rickie Smith was voted #1 Mountain Motor P/S driver earlier this year.
luxexpress
Nitro Member
I totally agree. Nothing, in my opinion, sounds meaner than an IHRA Pro Stock at idle. I am glad that Torco is drastically increasing the Shootout purse next year for this class.
hellfirejim
Nitro Member
I like to hear the air sucking in from all over the county into one of these 800+ inch pro stock motors at idle. What a terric and unique sound.
jim
jim
When Glidden, et. al, were running IHRA, they ran their NHRA-legal cars with a weight-break. Buddy Ingersoll also opened some eyes by running competitive times in a turbocharged, small-displacement Buick. It was almost as much fun as Comp Eliminator with all the different engine and weight combinations...
Good point, Larry. IHRA has always been open to trying new things. Unfortunately, they didn't always follow through. They pulled the plug on turbos in a heartbeat when Ingersoll was runner-up at a race. Neither Buddy nor Buick was pleased at how things went down and in my mind it was the main thing that drove Buick away from drag racing. Up to that point they were getting more and more interested, even assigning GM engineer Bernard Santavy as a full-time member of the crew charged with keeping the high tech engine packages in top shape.
As for variations,the year Jerry Haas won he was driving a small block Vega on nitrous. Back then there weren't any big cubic inch small blocks and when a St. Louis builder figured out how to build 450+ cubic inch engines it put him on the map for a couple of years. Sad, but I can't even remember his name now.
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Buzzz Miller
"What's the diff between NHRA and IHRA Pro Stock cars?"
About $20.00...and about 2000 RPM???
That is absolutely awesome!!
And we hear about the "What ifs" quite a bit when we start with this same discussion. "What if the Ken Black team had two weeks to build a mountain motor team and went IHRA racing. How much quicker would they be than the rest of the IHRA cars?" I get so sick of this type of talk. If you thing anyone, (and I mean anyone), can jump into this and can jump ahead of Kasse, Sonny, Miller, Fulton and the like, I believe you have another thing coming. These guys are not as out-back hillbilly as many are thinking. They know their stuff. It would take the Warrens of the world some serious time and some serious testing to be toward the top of that pack.
And there's diminishing returns as power increases. PM's are running 3 tenths better than IHRA PS and most of the IHRA AFC are appx 2 tenths quicker than PMs....SO the 4 tenths (give or take) the IHRA cars have on the NHRA versions indicate a considerable power increase.
The engine guy fron RM explained a lot about this subject but those posts went bye bye after the transition of the site.
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Buzzz Miller
Darin knows his stuff and really explains things well. He was a great asset to the Mater, but have not heard from him in a while.
But suffice it to say, that the IHRA stuff is no puppy. It has the highest piston speed of any race engine on this planet. When you get to those items, you get into some real problems with flame front travel, time close to TDC, and the valve size for the air needed to run in optimum performance for that cubic inch. There are physics in play that the NHRA guys do not deal with. The IHRA engines are intense!
But suffice it to say, that the IHRA stuff is no puppy. It has the highest piston speed of any race engine on this planet. When you get to those items, you get into some real problems with flame front travel, time close to TDC, and the valve size for the air needed to run in optimum performance for that cubic inch. There are physics in play that the NHRA guys do not deal with. The IHRA engines are intense!
Case in point; NHRA PS, touted @ 1500HP, NHRA TF, 8000 hp.
So, that 6500 HP gets you 2 full seconds in a slightly lighter car with a huge aerodynamic and engineering advantage.
A some folks assume if you throw 250 ci into a NHRA PS engine and test a few weeks, you'll rule the roost.
Man I wish I could retrieve that old thread.
Eric L Williams
Nitro Member
Darin Morgan---www.darinmorgan.com
