100% stock car how much more hp from dp?

[b4n30n3]

So say you have stock car with only a dp. What would that dyno at? And does anybody have a dyno of that?

[MS3kid08]

0 because its going to blow up.. needs and ap/fp

[bigriver]

[8.5MS3]

jesus fucking christ.....really

[b4n30n3]

Originally Posted by MS3kid08 0 because its going to blow up.. needs and ap/fp

I thought you could add a downpipe with stock computer.

[Alpha]

Originally Posted by b4n30n3 I thought you could add a downpipe with stock computer.

Stock computer... Yes.

Stock tune... Good luck.

Seriously, as long as you floor it from idle and no higher you should be fine. It gives the computer enough time to adjust.

PS - If you search and research you'd know I'm joking.

[G26]

You can do whatever you want, but why be an idiot and get bolt-ons without a tune on a motor that runs 15psi stock?

[Tokay444]

You need to read moar and post less.

[b4n30n3]

What happens if you put on a dp with no tune exactly? What are the problems that happen.

I have been reading quite a bit.

[G26]

Originally Posted by b4n30n3 What happens if you put on a dp with no tune exactly? What are the problems that happen.

Stock cam driven fuel pump could take a shit, which would cause the motor to run very lean, which would cause the motor to blow up.

[speeed]

Originally Posted by b4n30n3 What happens if you put on a dp with no tune exactly? What are the problems that happen. I have been reading quite a bit.

Zoom-Zoom-BOOM

[b4n30n3]

The guy with the ebay dp said his runs fine with no tune.

Are you saying that with just a dp you get fuel cut?

[SWAY]

Troll??? Or idiot???

[MS3kid08]

The stock pump has issues keeping up with the stock motor.. ESPECIALLY on a gen 2

Bolt ons just add that mush more stress to the pump.. fuel cut isnt the issues.. its lack of fuel pressure

you obviously havent read much, because every single thread says FP first

[Tokay444]

Originally Posted by b4n30n3 What happens if you put on a dp with no tune exactly? What are the problems that happen. I have been reading quite a bit.

MOAR!!!
With less posting.

[HARPER306]

op needs moar dying less living

[b4n30n3]

Why am I getting flamed so bad for asking a very simple question?

[G26]

hmm

[MS309]

Originally Posted by b4n30n3 The guy with the ebay dp said his runs fine with no tune. Are you saying that with just a dp you get fuel cut?

What everyone is trying to say nicely is that adding a DP would free up backpressure and increase airflow which would cause stress on the stock fuel pump and the stock fuel pump will crap out on you which will cause you to throw a rod through the block because not enough fuel. But every car is different and you could try your luck but in all honesty if you have the time and money to buy and install a DP it would be suggested that you buy an AP First instead which would be a much safer route to take. Or keep it all stock and live a trouble/tension free life.


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[greenespeed]

Originally Posted by b4n30n3 So say you have stock car with only a dp. What would that dyno at? And does anybody have a dyno of that?

What car are you driving ?

[b4n30n3]

Is it a fuel pump issue or a software/tune issue?
Speed3.
I do have a tune with my hypertech actually as well.

[MS3kid08]

your getting flamed because there is a search function which would have provided the info, that bolt ons with a stock tune and pump are a BAD idea... unless you have a spare block

[b4n30n3]

Originally Posted by MS3kid08 ESPECIALLY on a gen 2

What switched on the second gen exactly?

I have gen1

[greenespeed]

Originally Posted by b4n30n3 Is it a fuel pump issue or a software/tune issue? Speed3. I do have a tune with my hypertech actually as well.

Gen Won or Gen Poo

[MS3kid08]

HYpertech doesnt tune for a DP, IIRC

And the issue is both, stock tune sucks, and the pump is Barely adequit for the stock demands of the car

[MSMS3]

OP, please do some reading. There are numerous threads here on the subject. I'll give you one personal opinion. It ain't worth shit, scientifically, because its just one guy's opinion. If you are looking for opinions, I'll give you one. But, damn it, read and learn.

First, do you have a generation 1 or generation 2 car? It makes some difference. Mazdaspeed 3's from 2007-2009 have different ECU's and other differences from the current 2010+ model. Gen 2 is much harder to safely modify without upgrading the fuel pump.

I'll limit my remarks to gen 1, like my 2008.

1. Installing a downipipe without first addressing the high restrictions on the intake side is absolutely stupid. I can't think of any responsible owner who would slap a downpipe on to increase exhaust flow without first getting rid of the super-restrictive air box on the stock intake. An engine is an air pump. You have to increase flow on the intake side first. Any good SRI or CAI will do that and you will immediately gain about 15 whp.

2. If, and only if the intake flow has been increased with the CAI or SRi, then, and only then would adding a downpipe begin to make sense. We have a two piece downpipe and midpipe with two different catalytic converters. You do know that, right?

Both of those cats are low flow and introduce significant restrictions to the system. You could begin by taking out the midpipe and substituting a straight through "race" pipe. That will help.

Now, regarding the downpipe, you do know that is a very serious installation procedure on this platform? It is not to be attempted by someone who does not work regularly with hand tools and has access to a good lift or other easy access.

Are you in a state that has emission testing, and, if so, what kind of testing? Running catless v. catted makes some difference.

3. Now, having said all of that, I ran the MSCAI intake and a fully catless TurboXS downpipe/racepipe into the stock CBE and with one step colder plugs and did so without a tune, running on the stock ECU mapping for over 30,000 miles. It can be done and the combo does make a lot of power.

4. But, and this is a very important but . . . I also did this on the stock fuel pump, but I DO NOT RECOMMEND THIS. I only did this because I have monitoring equipment and was able to monitor boost, AFR's, fuel pump pressure. You WILL see boost spikes up to 21 psi running without a tune, and these can be dangerous. The colder plugs helped me somewhat. My pump pressures were o.k., but that was when the car was new and had lower mileage. Pump pressures have dropped over time and I've installed upgraded pump internals to remedy the issue.

5. I've also gotten an ECU tune. I chose HT, while others have gone AP. HT did eliminate the boost spikes and gives me a nice 18 psi target boost with gradual taper while maintaining safe AFR's.

Conclusion: Yes, you can do it. No, you'd be stupid to do it without first addressing the intake side and giving yourself a little safety margin against detonation by running one step colder plugs. No, you'd also be stupid to do this without monitoring boost, fuel pressure and AFR's at a minimum.

As to how much power you'd get from adding a downipipe to an otherwise stock MS3, I'd just have to say the question is too far out there for anyone to answer, because no one would do this and take the car to a dyno in that condition. If pushed for an answer, I'd say that if you installed a combination of a good CAI or SRI intake with a catless downpipe and racepipe connected to a stock CBE, you would have a serious power gain, probably in the range of 50 whp, but would be doing so recklessly unless you monitored and made sure you were safe.

[b4n30n3]

Take it easy on me I haven't been on mazda boards for years.


I have gen1.

[greenespeed]

Chalk up another fail for the Gen Won crew.

[MSMS3]

OP: People are not jumping on you for being new, they're jumping on you for being lazy and not reading the numerous threads. You do not have to be on the boards for years, but you do not need to be asking everyone else to do your homework for you when its already all here for you to read, if you take the time.

[captain slow]

This totally smells of troll. "Why are you picking on me?"

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[b4n30n3]

I know their are two seperate pipes with a cat on each.
So hypertech works good for dp? I run hypertech already.

As far as needing an intake first I am not sure if that is neccisarry. The k&n typhoon 69 costs $300 and an ebay dp is only $200. I was thinking to do a dp before an intake due to my limited budget and I was thinking to get rid of some of the heat in the engine/manifold/turbo area. If you let the exhaust flow faster out you should drop the temp wich should be good for safety I was thinking.

[greenespeed]

Bwaaaa Ha ha ha .... t r o l l...

[TexasSpeed3]

i smell troll on this one

[MS3kid08]

you will see little/ no gains, you obviously do not understand how an engine works..

you will not make more power unless you can supply the engine with MORE air and or fuel

and a Corksport intake can be had for 250

This guy is a tool he isnt even taking the info he is being offered

/thread

[b4n30n3]

I am doing my homework more than you guys think. I have been reading build diarys and dynos and big turbo threads. I have gotten quite a few pics off the board of engine and transmissions beeing rebuilt.

[MS3kid08]

then why dont u get the point that a downpipe as a first mod is DUMB?

[TexasSpeed3]

because trollololololol

[b4n30n3]

I understand exactly how an engine works. I am a mechanic, that's my job I do it everyday.


Because I think for just doing 1 mod to your car you will get more hp from a dp than an intake. Dp also cheaper than intake

[vrspeed10]

The only Bolton that can be done safely without AP and fp internals is a sri. Moddes to be done in order

1 fp internals
2 rmm
3 AP/tune
4 sri/tip
5 colder plugs
6 dp
7 upgrade intercooler
8 bpv

[greenespeed]

Just pull out the factory dp and leave it like that. Sounds amazing and really cools the engine fast. Thats how I'm running mine and I get compliments on it all the time.