Right now I'm rocking the BHR Midpipe...well..I guess the Midpipe prototype since he is releasing the revised edition soon. So far, with a stock catback (HKS Hi Power single was still over 90DB at 75feet) everyone says the car sounds like stock with an extra growl, and with a Borla or something else put on as a test, car sounds amazing. Weighs something silly like 7lb..? That's just my 2 cents. Not sure what I plan to pair it up with next year... we'll see.

 

Thanks Marc. That's definitely another option to consider (albeit a very pricey one). My only hesitation would be hacking up a $425 resonated mid-pipe to add the 100cpi cat. I'd much rather do that to the RX7store resonated mid-pipe.

 

Chiketkd, I track and AX my 8. I have the HKS single side exhaust also. I wanted the cat out for the track, since the heat tends to destroy the cat material. But then needed the cat in for AX.

I bought an RP Supercat pipe from RX7Store, we cut the cat off and made a short section of straight pipe. We used V bands for quick disconnects.
http://www.amazon.com/OBX-Steel-V-Ba...6829654&sr=8-9

This way I can quick swap straight pipe / hi flo cat pipe with just 2 bolts. I can post pics if anyone wants to see.

 

Interesting stuff. In my new class for next season, STX, I'll need to run a cat. I'd also like to run one one the street for environmental reasons, so a quick release change out like that wouldn't be necessary for my application.

FWIW, my 100cpi high flow cat is all-metallic and can withstand the heat a rotary dishes out! If the cat in your RP Supercat ever fails, shoot me a pm and I'll send you a link to where you can buy one.

 

Why not the Racing Beat dual-resonated mid-pipe? It's only slightly more expensive than the RX7Store pipe, and I expect it would be relatively easy to replace one of the resonators with a cat.

 

I burned up a stock cat this year. That's why I'm a little hesitant on the issue.

 

Take a look in the index of the FSM: SHIELD, SPLASH---------- 5390A -1

Maybe if you would have looked there you would have kept yours and been legal.

 

For what it's worth, Charles has mentioned it's their intent to sell an STX legal version of the pipe but they need to ironout the issues with their fabricator and the resonator first. Oh, and they have to select a Cat... I think he mentioned picking between a $100 one and a $500 one...

 

Well, I'm not a fan of buying more than I need. Only reason I'm considering a mid-pipe with a resonator is b/c I want add a header and I want to be sure my car isn't too loud afterwards. Otherwise, I would just get a catless midpipe, add the high-flow cat and call it a day.

 

Get the rx7store unit. I bought the RB non-resonated straight pipe, mainly because it had one more hanger than the rx7store pipe, but with the lighter weight unit (even with the cat & resonator added) you don't need the second hanger. In fact, my unit is light enough that the stock hangers are not stretched very far, and that, coupled with the larger diamter of the piping, results in the occasional rattle against a weld seam in the underbody, although it doesn't do that so much any more. So, to reiterate, the rear hanger on my setup is too close to the body to use the rubber link, so it just sits there unused. If I had to do it again I'd get the rx7store unit and save $30. Not that $30 amounts to much when you add it all up.

So, i'd say get the rx7store pipe, the RB "medium" resonator and have somebody mimic my configuration using that great davesport cat you've got sitting there. Great power, not too loud, and reasonably light. It's tempting to forgoe the resonator to save weight but it seems noise levels are becoming a bigger issue at nats. The locals complained this year.

 

That's my thinking George and probably the route I'll take. What 17x9" wheels do you have btw?

 

I still have my el-cheapo 17" Hot Wheels. They look cool and I get some great comments (Ron Bauer told me, when he was the starter one day, that he wanted to turn my car upside down to see what kind of car it was) but they are 4 lbs too heavy, or 1" too small, depending on how you look at it.

Given that I was .65 secs off Bryce on the east course at nats, I'm seriously thinking of going 18s next year. Heck, if you believe Jason's testing, if I had just switched to Dunlops I would have been FTD that day. I know it's not that simple, and those last fews tenths can come slowly (and expensively!) but I'm close enough now that I'm really starting to sweat the details. I just have to decide how many pairs of shoes it's worth...

 

Another thing I'd say about exhaust is you may want to see what Mark does. He may find a new trick or two the second time around.

 

Giving up on the 17's so soon? Do you think a different tire on your 17's might have given you better result?

I'm glad I don't have to make a decision for another 3-4 months...

 

Yes, it would seem that the Toyos were not a good choice, another tire on the 17s probably would have been faster. What is unknown is if the 18s would be faster yet. With Karl co-driving perhaps we'll be able to do a legit A-B comparison earlier in the season, and put the faster set aside for the NTs & Nats.

George

 

Exactly. That's why I said "probably." Clearly, the Toyos are fast on the ST cars at Lincoln. I've heard people complain about them overheating on heavier cars, but I never had that problem (but then I've never run them over 90 degrees ambient). And my treadwear is dead-even. So I do wonder if the spread Jason reported is valid at Lincoln.

 

Absolutely not, we even say so in the story. Those results are only valid for that track, that car, on those days. Different surface, different car, different time of year - even a different driver - will all yield different results.

I would have loved to do the test on concrete, but that stuff is in short supply (for our needs) in socal.

Based on the lack of any OPR on our tires, I am sure curious as to why they were so good on asphalt, but were not soft enough to pick up anything.

 

My Toyos picked up lots of OPR at Lincoln. The inside edges were completely squared off.

 

In my quest for STX wheels I'm currently trying to decide how much of a negative impact an extra 20mm of scrub radius would have on the steering and handling of the car (one wheel is +55et, the other is +35et)? Conversely, would the extra 40mm in track on the +35et wheel outweigh any negatives?

FWIW, both wheels fit under the fenders and wouldn't increase the overall 'width' of the car on course.

 

10th grade geometry.

 

I remember from a post of yours a few months earlier that you picked up a set of those +55et SSR's. I'm just trying to understand the advantage/disadvantage of the +55et over the +35et...

 

You can always add a spacer to the +55 wheel.

 

+40 with massaged fenders and 265's is a tight fit. I'm not sure you could squeeze a 265 on a +35 without limiting your camber options.

 

Also, don't give up on the Toyo's if you live in a colder climate. They are noticably faster than the Dunlop's at ~60 degrees.

 

Not sure if the +35mm offset Chike mentioned is a 17" wheel or not...

I just picked up a set of +35mm 17x9 RP-F1s for STX next season. Same size and offset as the FN01RC track wheels I've been running for the last two years. I honestly think the 17/255 vs 18/265 difference is going to be negligible at best, and with a baby on the way I can't justify the added expense for 18" wheels/tires. Besides, I'm still not convinced the 18s are the best option, money no object.

FWIW, +35 17x9 with 255/40-17 RA-1s/R888s fit under all four of my fenders without any massaging at all.