jasonsr1

According to Mazda Motor sports the Efini Y-pipe adds 10 hp. Has any one been able to confirm this in any way, boost or actual dyno tests?

wickedrx7

iTrader: (14)

I have heard of people getting .5-1 more pounds of boost. This might add up to 10 horespower, but I am not sure. I think it is an overestimation but it might be close. It is a good investment just for the fact you don't have to worry about the crappy rubber joints.

jr

Yeah I got it for the reliability factor and I installed it at the same time I did my downpipe so I can't really comment on it's effect on HP. It is great not to have to worry about that damn coupler popping off, and comparing it to the stock Y-Pipe I can see how it is designed better to provide smoother airflow thus possibly adding some HP. 10? Maybe at the flywheel, I doubt it's to the rear wheels though.

Jetlag

I got about 1psi increase over the stock Y-pipe. The stock y pipes have alot of proturdsion (BOV) on the casting and the bent on the cross over pipe is very tight.

Check out the Y: http://communities.msn.com/Meko/phot...oto&PhotoID=46

KillerRX-7

My car gets 15 PSI and all i have is downpipe, GT-Spec exhaust, and the y-pipe. I never heard of anyone gettin 15 psi with only downpipe e exhaust, so maybe the y-pipe is involved in that. yea i know,.. i need a ecu soon, i dont push my car that much right now, i just do it once in a while to see how much boost im getting. It jumps to 15 psi, then drops to 13, and 13 on the secondary turbo.

jasonsr1

Where can the Efini Y-pipe be purchased?

pp13bnos

iTrader: (1)

Mazda comp is the cheapest place to get them. I don't have the number right now though, CJ

jr

Jason's got them at the RX-7 Store for $225. http://www.rx7store.net/intercoolerpiping.htm

jasonsr1

Don't you have to be a member to Mazda Motorsports to purchase from them? I don't race.

jr

Only if you want to buy parts that you can normally get at a Mazda dealer. If the part is not available at a dealer (Competition stuff, J-Spec stuff, etc) then anyone can buy it from them.

Rx7aholic

iTrader: (22)

Hey Little info that I found out about the efini y-pipe leaking air and this is what I have found out. The front pipe on my primary turbo leak's and I removed everything to confrim where is the problem really is. After I remove eveything I noticed there r some black exhaust fumes on the front pipe that connect's to the primary turbo anyhow even putting to 2 gasket did not cure the problem, I looked at the front pipe and noticed that mazda stamp a # on it and that is where the leak is, also it does not sit neat on the primary turbo so I sand it down to have smooth finish it look better now only thing is to put it back together and test it, I remember soneone had post a question inthe summer saying have anyone noticed their intake make a louder noise after they installed the efini y-pipe this might be the solution.

SleepR1

I plan to replace my tired old stock twins with JDM J-spec '99 twin turbos.

I've been reading about this Efini Y-pipe, and it sounds like a good reliability mod, but I'm worried about the increase in boost pressure.

I have the stock ECU, with downpipe, high-flow cat, Trust catback. The boost is limited to 10.5 psi spikes using a slightly larger-than-stock waste gate control pill.

How will the Y-Pipe affect my boost tuning?

I'm not crazy about changing the boost pattern. I understand that the JDMs add a little more low end boost response?

FWIW, I have very stout SAMCO silicone couplings along with heavy duty clamps, everywhere where there is boost pressure being routed. I also use silicone rubber sealant at the joints for added boost leak protection...IMHO, I think this will be enough...??

Any informed opinions out there?

Flybye

My y-pipe DID give me an increase of almost 1psi, and I was actually spiking to about 13 psi before bleeding back down to 11, and this was BEFORE I had a DP. It was scary

It's a nice upgrade, but consider it if you ever plan on purchasing an IC that will require q rubber coupler above the Y-pipe. You can't attach one to it there because the efini is bolted to the upper pipe. If you plan on gettin an IC that would use the stock outlet location, then it's no big deal.
Mine may have spiked a bit too much because I had mine coated.

SleepR1

Thanks.

I do plan to upgrade to an M2 Large IC. From what you're saying, the Y-Pipe will not be compatible with an M2 IC Large with associated piping?

Flybye

Not as is. You would have to cut the efini-pipe to accomodate the rubber coupler for the pipe included with the IC.

The only other alternative I see would be to have a custom inlet pipe made designed to bolt up to the efini Y pipe so that you wouldn't have to cut the upper pipe.

jasonsr1

What does coating the y pipe have to do with boost spikes?

SleepR1

Well, I may just stick with my current setup with the stock Y-pipe, SAMCO couplers, etc, and not worry about all that stuff!

Thanks, Fly!

2-Rotor

I have a quick question where can i get good couplers for my intake? If you can name a supplier that would be great. Mine are stock and i am not having any problems now, but would rather change them before there is. Thanks

2-Rotor

Btw i am all stock and want to retain the stock air box and main plumbing to the throttle body. I just want to change the rubber couplings and clamps.

SleepR1

SAMCO silicon couplers are available from Advanced Import Motorsports. Call at 317.381.0898. Talk to Shane Benson.

Flybye

Jet-hot's coating leaves a finish similiar to as if I would have had the y-pipe polished. It leaves a much smoother surface giving airflow more speed.

Similiar example: My friend is having a custom exhaust manifold built for a single. The shop told him if he coats the exhaust, his spool up time will increase by about 500rpms.

jasonsr1

Don't you mean your friends spool up time will decrease. The rate of spool-up is in terms of time. The time it takes to reach effective rotational speed or speed at which boost is created.

Flybye

Yep Sorry. I meant DECREASE not increase. Why the hell would you spend a few bucks to reduce performance :p

GoodfellaFD3S

iTrader: (213)

The only thing I know about the Efini Y pipe is that I can hook it up to my bum , my roomates bum and his girlfriends bum and together we push about 18 PSI. Just Kiddin dude, I only know of one friend with this Y pipe and the dyno results are about a 7.5-7.8 HP gain at the rear wheels.

JeffShoots

$225 for 7HP that's cheap HP and your F-ing upper boost hose can't come off racing your best bud in his new 5.slow, only time he ever Won!!

Later, Jeff