Results 1 to 18 of 18

Thread: It7r

  1. #1
    Join Date
    Jan 2006
    Posts
    31

    Default It7r

    As many of you are aware, here in SEDIV there are a couple of really good though differing proposals floating around to try and save IT7. Both involve using the Renesis engine from the RX8. Both have pros and cons which can be debated.

    One version, set forth by Blair Stitt, uses fuel injection and includes upgrades to brakes, etc. The proposed rule set for the injected version can be found here: http://www.ncrscca.com/it-7r-rules. I can't provide a lot of information about Blair's version, as I have not been involved in that one. Hopefully, someone with more information can contribute to this thread.


    The other proposal, advanced by Estus White, is a carbureted version which utilizes the carburetor, front cover and distributor from the 12A. This version is intended to produce a car comparable to and able to race alongside the current IT7. An adapter is used to fit the 12A oil pan, as well as the intake. It makes use of only four ports to limit horsepower. Plus, using only four ports allows either the manual or automatic version of the RX8 to be a donor car. The Renesis engine is essentially used as a replacement “short block.” If the Renesis based engine is removed, you can reinstall a 12A and you have a fully legal IT7.

    Several years ago, I bought an IT7 to run in track trials and hillclimb events, with the intent of eventually going road racing. I chose IT7 because, in my mind, it was a lot of bang for the buck and I had always heard that rotary engines were pretty reliable. The car was a pretty good car, and I managed to set the course record for IT7 at the Wolf Ridge Hillclimb and run competitive times at other hillclimbs and CMP. However, like so many others have experienced, I eventually broke the engine. When I started looking for a replacement, I discovered what so many others already knew – they were hard to find and expensive. I wasn’t prepared to try rebuilding a rotary motor, especially as expensive as the parts were. I’m a pretty fair backyard mechanic, but all my previous experience was with Ford V8s. I figured out I could buy another car for what a new motor would cost, so I bought one from Jim Hess up in Maryland (2 time MARRS IT7 championship winning car), and put the first car in the garage. I figured if I wrecked the new car, I’d have a spare chassis, but I really wanted to find an engine so I’d have two cars.

    A mutual acquaintance told me that Estus was looking for an IT7 to use as a prototype IT7R. I offered the use of my spare chassis, and Estus pulled the broken engine out and put the Renesis in. A carbureted IT7R was born!

    Recently, the carbureted version of the IT7R ran its first two events, first at the Chasing the Dragon Hillclimb in late June, and then again at Roebling Road June 30 - July 1.

    At the hillclimb, the car (driven by Estus, who has tons of hillclimb experience including holding the course record at several sites in RX7s) posted a time of 2:21.817, compared to the course record of 2:20.922 (set last year). (The only other IT7 at the hillclimb this year broke on its first run. Another IT7 needing a new engine).

    At Roebling, Estus' son Ess drove the car. After the race, Estus sent me an email saying "The car is dead even competitive with IT-7. Less than 1/2 second difference in lap times compared to the IT-7's. Not over competitive, not under competitive. We ran what would be 2nd place in IT-7 for most of the race...." A late problem with the fuel pump both days caused the car to begin missing, so the car fell back at the end of the race both Saturday and Sunday.

    There have been a number of threads on here about IT7s and the motor replacement issues. A couple mentioned these two proposals, so I wanted to give everyone an update on the progress to date on the carbureted version. Hopefully, both versions will be represented at the upcoming MARRS / SARRC at Charlotte Motor Speedway in August.

  2. #2
    Join Date
    May 2008
    Posts
    21

    Default

    If I am to put such an upgrade in my IT7 the last thing in the world I want is the carb and the dizzy. Those are two things I can do without. As for the brake upgrade, why wouldn't I want that already? 2nd gen guys go forever without replacing pads and rotors, and when you do, you pull the rotor off and throw a new one on rather than changing out the studs and packing hubs between sessions. The injected version in my mind is the only way to go. If I stuck with the carb, I would still be dealing with fuel issues as it sounds like the test mule did, plus you can't even get gross jets and other parts for the carb anymore. Why keep it? Heck, NASCAR finally got rid of the carb, why not us too.

  3. #3
    Join Date
    Jan 2006
    Posts
    31

    Default

    I repack wheel bearings between every race weekend and replace rotors regularly. Its just part of my routine maintenance. I've never had to replace a rotor on a race weekend. I've not had a problem with the distributor or carb. As I stated in my initial post, the problem at Savanna was the fuel pump. Having said that, I would like to see a Holley option worked into the rule set.

    The intent of the carb version is to create a car which can compete on an even footing with current IT7 cars. The injected version is more of an "if I could change everything I don't like about my car, what would I change" version (my words, not Blair's). That's not what I want to do. By the time I pay for the Renesis engine, fuel injection, brake upgrades, new wheels, etc. I've spent a ton of money. Plus I have to wire the engine management from scratch and learn how to set up electronic engine management. Not for me. The carb version conversion is estimated to be around +/- $1500 plus the donor Renesis.

    Based upon comments made by Blair at the SEDIV meeting in January at Jekyll Island, the injected version is projected to produce 180 - 190 hp. This car would not be comparable in potential to current IT7. Based upon the results of the first two outings, I believe the carb version could be classed as an IT7 car and compete heads up with the current cars, with perhaps slight weight adjustments. Plus, other than the "replacement block" it is an entirely legal IT7 car. Like I said earlier, drop a 12A in and its a fully legal IT7. That's no where close to true with the injected version.

    Again, not an either - or argument. BOTH cars should have an opportunity to compete. The market will decide.

    However, I think there would be enough interest in both versions, and there are enough of these cars out there with bad engines, to support both version.

    Make no mistake, I think they are both GREAT options, they are just NOT interchangeable.
    Last edited by highwayracer; 07-11-2012 at 02:00 PM.

  4. #4
    Join Date
    May 2005
    Location
    Staying off the walls
    Posts
    1,049

    Default

    I have no dog in this fight since totalling my IT7 in May and having parted most of it out already. However, if given the choice between the two options I'd have to go with the FI, no dizzy, better brakes, no adapters, etc.

    Why take two steps forward and one step back?

    BTW, anyone need a 3 link & pandhard 4:88 LSD axle, or a set of RA1 rains, or 7 heat cycle RA1 shaves, or a couple of complete race prepped front struts with Tokicos and brake ducts?
    Tom Sprecher

  5. #5
    Join Date
    Nov 2005
    Location
    Woodstock, GA
    Posts
    547

    Default

    Since we're still very much in the developmental stage for both options we will NOT try to submit anything for approval by the SEDiv REs at the July 21 Mid-Year meeting. All the principles are planning to attend the Double SARRC / Double MARRS weekend at Charlotte August 17-19, so I'll be able to knock some heads together and still have time to get things approved prior to the start of the 2013 SARRC season (Oct 13).

    My main objective (besides achieving relative parity) is giving people a choice.
    Butch Kummer
    Former SCCA Director of Club Racing (July 2012 - Sept 2014)
    2006, 2007, 2010 SARRC GTA Champion

  6. #6
    Join Date
    Feb 2008
    Posts
    601

    Default

    Quote Originally Posted by tom_sprecher View Post
    I have no dog in this fight since totalling my IT7 in May and having parted most of it out already. However, if given the choice between the two options I'd have to go with the FI, no dizzy, better brakes, no adapters, etc.

    Why take two steps forward and one step back?

    BTW, anyone need a 3 link & pandhard 4:88 LSD axle, or a set of RA1 rains, or 7 heat cycle RA1 shaves, or a couple of complete race prepped front struts with Tokicos and brake ducts?
    How much? Specifically the 3 link, panhard, and tires,

  7. #7
    Join Date
    Mar 2002
    Location
    Black Rock, Ct
    Posts
    9,594

    Default

    I used to own an IT7, and....I blew my last good engine a couple years ago. Mazda lacked the seal kit to repair it for about 6 months, and life has taken over, so I'm an interested observer. But not a committed participant.
    From my point of view, ANY difference between an IT7 and the 'new IT7' is enough to create a non even class.

    in other words, you have had ONE driver at ONE event and you're calling them 'even up". That isn't really anything near enough testing. And I predict no amount of testing will convince everyone that they are the same. Different torque curves, different power curves, etc etc.

    Understanding that, then, why deal with the headaches of carbs and those awful brakes??

    The rotors are getting more expensive and they go through them like water when you start pounding on them...(like you have to).

    If I were in the position, there's no way I'd choose the choked down version.
    Also, there's NO way I'd accept a Renesis powered "IT7" as an IT7 that could reset track records. Thats the bottom line to me. I raced for wins and track records. I maximized my car based on the ITCS rulebook. If it's going to be called an IT7, it has to be built to the SAME rules as the cars that set records.

    Just some thoughts from a guy who used to swim in that pool....
    Last edited by lateapex911; 07-13-2012 at 11:20 PM.
    Jake Gulick


    CarriageHouse Motorsports
    for sale: 2003 Audi A4 Quattro, clean, serviced, dark green, auto, sunroof, tan leather with 75K miles.
    IT-7 #57 RX-7 race car
    Porsche 1973 911E street/fun car
    BMW 2003 M3 cab, sun car.
    GMC Sierra Tow Vehicle
    New England Region
    lateapex911(at)gmail(dot)com


  8. #8
    Join Date
    Jan 2006
    Posts
    31

    Default

    Jake,

    The "even up" comment was not meant to be a declaration of the potential of the car, but rather a description of the way the car ran at that one event. The upcoming MARRS / SARRC at Charlotte will give another chance to see how the car runs.

    As to "...why deal with the headaches...?", you answer that question yourself in your post when you make reference to the ITCS rulebook. In rare instances, parts substitutions have been allowed in IT when there is no availability of the original part. Those substitutions have been the minimal amount required. The carb version is an attempt to address the parts shortages with the least deviation from the ITCS rulebook. As I stated in my original post, take out the Renesis based engine and put a 12A back in, and you have a fully legal IT car.

    The FI version, while a neat concept, is NOT an IT car.

  9. #9
    Join Date
    Mar 2002
    Location
    Black Rock, Ct
    Posts
    9,594

    Default

    yes, there have been some allowances in the ITCS, but those were years ago. I would bet money the ITAC will not make any similar allowances in the near or distant future.
    And they'll never put the Renesis in LOL.
    But hey, it's cool, and I hope the guys have success, and can keep running races, as opposed to walking away from the sport.
    Jake Gulick


    CarriageHouse Motorsports
    for sale: 2003 Audi A4 Quattro, clean, serviced, dark green, auto, sunroof, tan leather with 75K miles.
    IT-7 #57 RX-7 race car
    Porsche 1973 911E street/fun car
    BMW 2003 M3 cab, sun car.
    GMC Sierra Tow Vehicle
    New England Region
    lateapex911(at)gmail(dot)com


  10. #10
    Join Date
    Feb 2008
    Posts
    601

    Default

    If I was going this route I'd choose the FI better brake version, sounds a little more complicated and probably costs more, but the end result would be more satisfying in my opinion.

  11. #11
    Join Date
    Jul 2004
    Location
    Raleigh NC
    Posts
    3,682

    Default

    The carbed version is appealing due to relative simplicity and lower cost. But, having recently kicked the carb habit at chez Earp I'm really enjoying EFI and would choose the EFI IT7R option.

    However, I suspect the EFI IT7R option will take more money and loads more development time. And of course the performance of that package is going to necessitate further changes to other subsystems of the car.

    In the end, neither are IT7 in the current form.

    It appears that people are finding ways to continue racing the 13B in ITS. Was the 13B considered for "IT7R"? Although it'll face the same problems as the 12A at some point. And, the Renesis might also experience difficulties with cores at some point far down the road now that Mazda as pulled the plug on the Dorito motor.

  12. #12
    Join Date
    Jan 2006
    Posts
    31

    Default

    Ron, you hit the nail on the head. My belief is the carb version is much easier for the backyard mechanic type (me) and a lower cost option.

    By the way, I've followed with great interest your Mustang build, as I bleed Ford blue. In addition to my IT7s, I recently bought the ex-Capaldi ITS Cougar that was listed in the classifieds here six months or so ago. Its a fun car, but I've got to learn how to drive front wheel drive. Plus, after years of driving on the IT7 spec Toyo RA1, I think my butt's been lying to me.

    Are you bringing the Mustangs to Charlotte? If so, I'd like to stop by and say hi and check out the cars.

    Larry

  13. #13
    Join Date
    Jul 2004
    Location
    Raleigh NC
    Posts
    3,682

    Default

    Quote Originally Posted by highwayracer View Post
    Ron, you hit the nail on the head. My belief is the carb version is much easier for the backyard mechanic type (me) and a lower cost option.
    Maybe.....

    Today's younger racers are more at home tuning with a laptop than wrenches. And, to be honest while I can do both well I much prefer dickering with fuel and spark maps on my laptop than changing jets, turning dizzys, and adjusting needle heights.

    So is the goal to placate the older IT7 group, or to get new blood into an entry level class?

  14. #14
    Join Date
    Mar 2002
    Location
    Black Rock, Ct
    Posts
    9,594

    Default

    Quote Originally Posted by Ron Earp View Post

    In the end, neither are IT7 ......

    .
    This is something that must be understood....
    THEN a strategy can be formed.
    Jake Gulick


    CarriageHouse Motorsports
    for sale: 2003 Audi A4 Quattro, clean, serviced, dark green, auto, sunroof, tan leather with 75K miles.
    IT-7 #57 RX-7 race car
    Porsche 1973 911E street/fun car
    BMW 2003 M3 cab, sun car.
    GMC Sierra Tow Vehicle
    New England Region
    lateapex911(at)gmail(dot)com


  15. #15
    Join Date
    Jan 2006
    Posts
    31

    Default

    Quote Originally Posted by Ron Earp View Post
    So is the goal to placate the older IT7 group, or to get new blood into an entry level class?
    Both!

    As I stated in my initial post, I believe there are enough of these chassis around to support both versions, but they are NOT interchangeable.

    But think of this perspective. The number of IT7s is dwindling. Several of the participants in this thread are former IT7 drivers who have not been able to find or are unwilling to pay the cost of replacement engines / parts, especially for a class with an uncertain future. On the other hand, there are some IT7 campaigners who have plenty of parts. I spoke to an IT7 driver last year at an event that said he has, I believe, 11 running 1st gen cars. He has parts to last forever. At some point, IT7 car counts are going to drop to the point that it can't support its own class. I understand the argument raised earlier against allowing the carb version into IT7, but unless something is done, those guy with plenty of parts are going to end up back in ITA. If the choice is running with a carbed Renesis or in ITA, I suspect the carbed Renesis might be a little more attractive. I'm not saying more testing and adjustment isn't needed, but having the discussion is a step in the right direction.

  16. #16
    Join Date
    Feb 2008
    Posts
    601

    Default

    Bumping this back up because I saw the SEDIV site had the class added to the regional rules now. Seems very appealing, especially after looking at 12A options recently as I'm worried about the future of my motor.

    Looking around at used RX-8 motors they aren't too hard to find at a good price and with the brake and transmission options I think I'll go this route when my engine goes.

  17. #17
    Join Date
    Mar 2002
    Location
    Black Rock, Ct
    Posts
    9,594

    Default

    Glad it's an ADDED class. Just changing engines and not changing the class name would be really, well, not smart.

    That said, I imagine that conversion to an RX-8 motor and trans, plus the needed brake upgrades will cost easily what the car is worth. But yea, it keeps the car going so thats good.
    The end of the line is always a tricky time for a racing class...
    Jake Gulick


    CarriageHouse Motorsports
    for sale: 2003 Audi A4 Quattro, clean, serviced, dark green, auto, sunroof, tan leather with 75K miles.
    IT-7 #57 RX-7 race car
    Porsche 1973 911E street/fun car
    BMW 2003 M3 cab, sun car.
    GMC Sierra Tow Vehicle
    New England Region
    lateapex911(at)gmail(dot)com


  18. #18
    Join Date
    Jan 2011
    Location
    raleigh area
    Posts
    4

    Default

    well as a long time mazda racer (ita rx3) and crew on a it7 and 2nd gen car, and now a 2nd gen its owner, heres what i think. yes i am biased, estus is my car builder and friend. the thing is putting a rx8 motor in with fi and completly open engine management is not what it7 was concieved for in the first place. the class was started to give rx7s a place to run where they didnt have to compete agaisnt computer fi cars.
    i think that there is too much potential for the fi cars. not to mention adding better brakes axles and so forth. if you want to run a st car build one for that.just my7 two cents. i like blair, ive known him for a while and even bought a racecar from him. i think that the open version of the it7r has the potential to run its times, given the money to develope the setup and engine management

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •