Ranger Yi

yup.. with the restrictor plate that chuck gave me.. it fixed the boost creep.. so thats good.. chuck said my car should be making close to 300whp with the mods i have on the car.. do you guys think thats about right?

JONSKI

At 10psi, yes.

You could probably run 13 or 14 psi with the stock fuel system.

RotorMotor

iTrader: (5)

the ristrictor goes where? your talking about twins yeah?

dgeesaman

iTrader: (7)

Call me a wiseass, but what's the point of putting in a midpipe (and getting all the noise and stench) just to put in a restrictor plate? Why not do a high-flow cat in the first place? Does a restricted mp still make more power than a high-flow?

Dave

mibad

^^Wiseass. Talkin bad about about the creep's midpipe...

Jodeny

iTrader: (3)

I agree with the wiseass<grin> It is a WASTE of time to put a restrictor plate in to control boost creep. You modded the car to go faster...and then you slow it down? Rotaries need to breathe, take out the plate(band aid) and get an adjustable orifice to steady your boost creep and then use a boost controller on the PFC to control it.
John

cewrx7r1

iTrader: (2)

Oh grasshopper, you do not know what you talk about!

(1) Boost creep with the stock turbos is caused by the stock WG being too small to controll boost with any boost controller that I know about when running a straight through exhaust system.

(2) A proper restrictor plate might reduce power back down to that of a hi-flo cat
but is cheaper and WEIGHS less thus an advantage. Before porting my WG and using the same restrictor while running 12PSI boost, I hit 170MPH while testing the same restrictor and ran out of road.

(3) With the air pump still working and pumping into the exhaust manifold, it does not smell that much.

(4) Since Ranger Yi could not currently afford a hi-flow cat, or get his WG ported, this was the next avenue to more power.

Jodeny

iTrader: (3)

Grasshopper my ***. Dont get wise with me, Chucky... we spoke on the phone 5 years ago and you were a nice guy...what happened? Ego got stroked? If you dont like my post fine, then disagree intelligently. I know what causes boost creep and I'll say it again, a restrictor plate is a band aid fix that IS NOT necessary. I know you've been working on these cars for years, you should know how to control boost creep by now.........I shouldn't have to tell you. I ran my stock turbos for years...on a ported engine and still easily controlled the boost creep...all the while using the PFC to control boost. Hey..it's not my car losing HP...

John

RotorMotor

iTrader: (5)

first of all.... if you get the same performance from a HF cat and a midpipe.... for gods sake use a HF cat. i do. i have a cat with a metalic core, and it only weights 10lbs total. there is no excuse to not run cats.

first of all, our FDs pollute enough... theres no reason to make it 1000 times worse.

secondly, it smells. bad. your clothes stink, your hair stinks, and youll be lucky if your girlfriend comes near you.

third, theres not much of a performance gain over a metalic cat. i had to port my wastegate after installing my metalic HF cat cause i was getting boost creep as well. trust me when i say the metal substrate ones are where its at. all the benifits, none of the drawbacks.

fourth... i loved the performance of this cat so much that im using one in my 20b FD! depending on how far i decide to push the motor, i may decide to run a dual cat setup (in parallel) which should be possible seeing as the entire core is only 4" in diameter.

if you want links to various metalic substrate options ican post them if youre interested. just ask. -heath

Mahjik

iTrader: (1)

Guys, I seriously doubt a restrictor plate is restricting the exhaust that much to rob it of any real power.

The only power it's really robbing the car is of the extra boost that was obtained by not being able to control it in the first place. Think of the size of an exhast gasket , that's about the thinkness of the plate just to cause enough restriction to bring the boost under control. So you are looking at about an 1/8" restriction. How long is a converter? A little longer than 1/8".

cewrx7r1

iTrader: (2)

I thought my 4 points described the situation intelligently so that you would understand Ranger's situation, but evidentily all you want to do is argue.

McBride61

Ummmmm *Raises hand*

How the F-CK am I supposed to learn about these cars when everyone just argues about what is right/wrong.....

For me I had a clogged stock cat. My options were to get a high flow cat or a midpipe. I knew I would have to get a
PFC w/my midpipe. (I dont want to do anything close to the edge of blowing a motor) PFC was also for future upgrades.

I was told by a few different mechanics. Rotary and non that if my cat was clogging a high flow cat would eventually clog
also(After a long while). A midpipe it was....

My non-car realted logic:
So High flow cat...... still has a cat right? If it does, then whats the point? If I have to replace it every 30k(or so) I mean
a high flow cat is still more restrictive then a midpipe, right??? I live in BFE so I don't need to worry about emissions.

Ranger Yi- What mods do you have?

G's 3rd Gen

iTrader: (11)

I think you answered your own question. Basically its your own preference at this point. If you don't mind the noise, the stench and can get away w/ it. Use a midpipe! A resonated mid say from Pettit cuts the noise at low rpm a bit. A borla center section helps alot. In your case I would def. midpipe it!!

cewrx7r1

iTrader: (2)

Since he is having fun in Vegas right now, I will answer for him; his mods are listed in his post which started this thread.

dgeesaman

iTrader: (7)

A couple of the high-flows out there handle the heat much better than an ordinary cat. Now if a muffler shop just welds in any high-flow, yeah 30k might be all it lasts. So the clogging should not be a major problem with a good hi-flow (e.g. Bonez). I dunno how long they last - 60k, 100k, that's not a big deal for high-maintenance cars.

Dave

cewrx7r1

iTrader: (2)

As far as the comments about stench of not running a cat; if you run a PFC along with a working air pump, you can tune the idle area so that there is almost no smell.

This includes overridding the main cause of the smell which is Mazda's very retarded idle timing. If you look at the displayed timing as compared to the map, it does not match and has more retard. If you use a DATALOGIT you can force the PFC into submission where it will allow you to adjust idle timing to how you want it.

When you do this your rpms go up due to the engine burning the fuel more efficiently. Thus you then adjust for less air and less fuel. You end up with a more lean burn. Here is my idle timing for N1-N5 for P1-P5:
17 17 17 23 28
17 17 17 23 28
17 17 17 23 28
17 17 17 23 28
17 19 19 23 26

Did you know that Mazda retards idle timing by 15 degrees when the water temp is below 60C/140F. Just by increasing it to 5 degrees most have found that cold starting/idleing is better.


You can also lean out the cruise area of the map for a cleaner burn and better mileage. But then you have to have the proper tuning equipment and know how to tune the PFC.

OKRX-7

You could remove the twins and port your wastegate, about a 3 hour job, and well worth it. Just avoid the OMP lines when pulling the turbo's out!

John Magnuson

Well... not running a cat would trap less heat in your exhaust system. Might make the car a little more reliable under extreme conditions? Kinda like removing the pre-cat?

FWIW I've always run with a cat even at the track without problems.

RotorMotor

iTrader: (5)

it seems like us CA folks (because we are FORECED to run a cat here) have found ways to deal with problems with the stock catalictic converters. yes the stock cat and pre cat will eventually clog. usually this is due to the ceramic honeycomb disintegrating and restricting flow channels. this doesnt happen with metalic substrate cores.... as they are METAL. also they are much more efficient (less material = more flow), and also heat up quicker (negating the use of a precat for cold start emmissions). they are said to flow "almost as well as a midpipe" and after owning one i do not doubt that. they also weigh almost the same as a midpipe. AND if you already own a midpipe.... you can buy JUST a core, and have a muffler shop simply weld it into your midpipe.

Its light, efficient, and flows well. i cant see any reason NOT to use one. come on guys, its not 1967. (infact... my 1967 MGB smells better than my FD without a cat). catalictic converters are here for a reason, so please use one. (i feel like im trying to convince 7th graders to use condoms or something ) if you want resources let me know -heath

cewrx7r1

iTrader: (2)

I hope you do not attend any legalized racing event since that would mean that you are supporting racing without cats.

If you also fly on commercial aircraft, it is even worse. http://www.sdearthtimes.com/et0400/et0400s7.html

Then are own goverment pollutes with freedom from execution.

What me worry?

RotorMotor

iTrader: (5)

hey man.... im just trying to do my bit.

and if there are nothing but benefits from the metal cats... then why not? i dont know... you guys do what you want. im just saying theve worked for me very well.

re_rotary7

to answer the original question.....mcbride61 (who posted in this thread) put down 298rwhp with dp/mp/stock exh/pfc/intake. this is on base mod map with conservitive timing at about 12psi with no creep. so yeah, you should be about 300hp.

Ranger Yi

thanks for all the replies guys.. yea like chuck said i've been away in vegas and just woke up ahah.. it was a fun trip. .but i lost money.. and thanks for answering my questions..

PS: CHUCKS the man when it comes to rotaries.. too bad he's moving away..