I recently purchased a J's Racing 70RR headerback in stainless steel. I was doing some searching and came across a few old threads that mentioned running the 70RR can cause a lean condition in VTEC at wide open throttle. However, it was not clear whether they had an '06+ or used it with an aftermarket header.

The general consensus I gathered was if you use an aftermarket header with it, you will definitely cause a lean condition and knock without proper tuning. However, I found conflicting opinions regarding conditions using it with a stock header. I did come across this post:

So has anyone with a stock header datalogged their air/fuel ratios with the 70RR, particularly AP1 owners? Will my '02 AP1 need a tune?

Exhaust should be here later this week, I'll be sure to post a review when I install it.

Feel free to chime in if you have a non-resonated 70mm+ single exhaust with a test pipe (Berk 3", Challenge TA-R, etc). results should be comparable.

 

Need one? No. You won't need one. It will run a tiny bit lean with just means you won't get every HP out of the exhaust that you could but the stock comp will compensate some just not as much as a custom tune could. You will be fine.

Also you don't have many options for tuning. You have the stand alones which cost way more than the exhaust and then you have Greddy Emanage which is ok but there does not seem to be many people that tune it and at the end of the day it is still a piggy back so its not as robust as the stand alones.

Something you could do is install a wideband which will tell you your AF ratio so you can see if it does go lean at any point.

 

I can get you one the next time I stop by the dyno.

While you'll be *okay*, you'll be running on the leaner side than stock, obviously.

 

Thanks for the input guys. The problem from the researching I've done is that the few people who warned of leaned conditions posted data or actual A/F numbers from first hand accounts, but were dismissed by the majority who just said "you'll be fiiine", but I never saw any data confirming that. And that seems to be the general consensus, despite the little data out there stating the opposite. Most point to data from other 70mm exhausts w/ a test pipe, but most other 70mm exhausts don't flow as well as the J's.

I'd wager 00-01 owners with the rich factory tune would be ok, and I might be ok with my 02 ECU. I'd certainly be nervous if I had an '06+.

A dyno graph with A/F ratios or just feedback from those who have datalogged would be helpful so I know what I'm going into, as well for the significant amount of people also running this exhaust. I'd bet a good portion of those are still on the factory tune.

I'll have to see about getting some dyno pulls to see where I'm at.

 

So fed ex dropped it off today. Have to say my initial observations are disappointing, though it might be just because of false expectations.

I don't know, you guys tell me.

The box. HUGE lol



just unwrapped the canister. Hmm...I thought it was supposed to be polished? why is the finish so dull?

A far cry from the mirror shine my GReddy SE had





At least its authentic, sorry for the glare



welds...disappointing. I mean, functionally I'm sure its fine and won't leak, and this is the rear of the canister so you won't see this once it's on the car. Still disappointing comparing it to my GReddy SE, where every weld was super tight, especially since this is just a non-resonated single and it was more expensive.





Looks good here, except for the scratches





There were also fairly deep scratches on the canister I didn't take pictures of. Meh

What's weird though, is the piping is polished and super reflective and shiny, but the tip and canister isn't...what the hell is up with that?!

Haven't put it on the car yet. I might try to polish the canister...I've refinished polished aluminum wheels before and the process for stainless steal is the same, just more difficult because of the hardness of the metal I've heard.

 

Thats definitely a brushed finish and they should have said so in their advertisement. I'm guessing they had different people do the welds. An experienced welder for the visible part and a novice for the places you cant see probably to save money on labor.

On another note, I think the brushed finish looks good

 

Whyed you get rid of the greedy? Was that a dual or single? For sale? Sucks about the welds and the not shinnyness, return it since you spent so much and not perfect?

 

I like the look of it, I agree about the one weld looking bad, the front weld looks nice, I agree with the comment above that they used a better welder for the visible part and cheaper welder on the rest.

 

the weld on the tip to muffler is a machine weld, while the other is hand welded. that's why they look so different. a lot of times, there is a restriction on machine welding due to size/shape of the exhaust. Most likely, the tip was machine welded to the muffler first, then the muffler assy hand welded to the rest of the piping.

 

Yeah definitely agree that one was machine welded, the other is by hand.

I mean there's no leaks, I'm sure it'll hold up fine, just not what I'd call pretty ha.

Anyways, it's on the car now, pics later. I only drove it around for about 3 miles, had to pull it in because of rain, I didn't even get into VTEC. It is loud though, obnoxiously loud.

Pics later