heidihi

for being somewhat reliable first off.. cause i know if i stress everything it is possible but i want to keep it working for a while!

is it possible to take stock ported motor, and stock twins and get it to pump out around 350whp? if so what mods would be needed and how much boost will need to be ran etc.. i know its all dependant on the tune of course but to make the tuners job the easiest what all would be needed?

ive searched but its like i said at the very begining..

rx7store claims 340whp with there stage 2 performance mods.. so i dont see why i couldnt get more than that or same as.. anyone wanna walk me through this?

:-D

Stage 1: 300 RWHP Upgrade Package.

Catback Exhaust System, Intake system, Apex Power FC, Downpipe.

Stage 2: 320-350 RWHP Package.

Stage 1+, Fuel Pump Upgrade, Midpipe, Intercooler Upgrade.

this also makes me wonder can the stock injectors really hold 350whp? i thought they were done around 330hp or something like that? cause if your on there site it says injector upgrade should come at 380hp?? sorry just a lil confused by there site.. i could be way wrong tho thats why im asking.

Mahjik

iTrader: (1)

Possible? Yes. Likely? No. You'll probably need around 16-17 PSI to get there.

heidihi

what do you suggest, i just editied my post to add more information. id love to be at 340whp on a stock motor n twins and run stock injectors. but at the same i find it hard to be reliable etc.. its why im askin :P

pinkrx7

iTrader: (2)

to get there realiably u need a new turbo. whether bnr or single its up to you. stock turbos aren't reliable at hi psi

FearNoPiston

iTrader: (17)

do the mods get a tune and see if your happy with how fast it is not what numbers it shows.

You will need to get some more fuel if you want to be under 80 percent injector duty.

j9fd3s

iTrader: (3)

on a stock motor 320ish hp occurs at 15psi, which is already kinda high for reliability/longevity. its plenty fast though

if you use a boost controller, you could have a high/low boost setting.

moconnor

iTrader: (14)

True. Too many people aim for arbitrary horsepower numbers. 300 whp is already stupid fast in this car because of its weight. Most modern sports cars are 300-500+ lbs heavier.

The jump from 300 to 350 whp on a stock motor and turbos will take the car outside of its already poor reliability zone.

grimple1

iTrader: (1)

i really want to make 349whp... but 350 is also tempting.

heidihi

didn't say that.. I'm questioning there mods list and claims.

bryant

very good point.

sounds like with your goals it would be safer to upgrade your injectors, fpr,fuelpump and if your going that far stick a big single on it and achieve your goal very easily.

bryant

but that still wont make it reliable.lol

matty

i am surprised that alot you feel it isnt achievable. 350 rwhp on stock motor stock twins used to be a dime a dozen. do all the boltons with some fuel mods and run 15psi and you are there, easily!

heidihi

matty that is kinda what i was thinking.. i mean people are hitting 400 doing this at 17-18psi with all the bolt ons so i dont see why the 350 mark isnt there with the bolt ons and 15psi?\

then i go tot he rx7store website and they have there levels of performance like i listed in the first post. and they are claiming near 340whp with there stage 1 and 2 mods on a stock port and stock twins at 14psi.. so why couldnt 15psi do it?

i do plan to upgrade my injectors and so fourth also, as i already have a pump installed.. but i was refering to the rx7store website as how there stage 2 mods still dont list injectors and there claiming up to 350whp.. and there stage 3 mods shows 380whp and it includes injectors.. im not arguing anyone im just stating there site claims this and im curious about it.

Mahjik

iTrader: (1)

There has been one person to do that (i.e. 400 rwhp on stock turbos and stock ports). This is why I said it's possible, but not likely. At 15 PSI on stock ports and stock turbos, typical is around 330-340rwhp. That's realistic.

FearNoPiston

iTrader: (17)

+ the guy mahjik is talking about turn the boost on the stock turbos up to 19 to 21 psi.

heidihi

holy crap.. that i didnt know about.. but still were talkin around 340whp at 15psi.. which is still pretty decent with all the bolt ons..

moconnor

iTrader: (14)

Didn't you use the word 'reliable' in the original question? 15 psi will curtail the life of the stock twins; 13 psi is a good compromise between reliability and power, and will give you ~320 whp on a good day.

heidihi

i did say reliable.. but i mean more for the motor itself.. the twins can go out i wont care.. that will just get me ready to upgrade them.. but im more worried about me hurting my engine itself.. and that being said i dont want my car trashed in the first week.. id like to get a good year driving out of it.. granted my year of driving prob equates to 2500-3500miles which most are not me with my foot in it hardcore..

Tom93R1

iTrader: (2)

I can believe the 320-350 on stock injectors but thats seriously maxing them out and leaving no safety margin. It will require a higher AFR tune and maxing out the duty cycles. It seems more like 300-320 as being the upper limits of safe. Running 4x850cc injectors will get above 350 safe.
Stock unported motor at those boost levels not confident about the numbers either. I could only manage about 310 @ 15psi before I ported my motor (with intake, IC, full exhaust and no cat). That was with Steve Kan tuning, I know he is a bit on the conservative side but like you were saying you want "reliable".

moconnor

iTrader: (14)

You will need a duty cycle of ~95% to get 350 whp:

http://www.rx7.com/cgi-local/3rdgencalc.cgi

While there is a lot of debate on this, some report running those sort of cycles on FDs for many years. I've been running 90% for several years.

However, running twins at 15 psi not only wears them more rapidly but will generate lots more heat than stock, accelerating coolant seal wear.

heidihi

like i said im not really planning to run stock injectors, it as more of a what the when i seen there site. but then again 15psi on the stock twins if you do plenty of cooling mods and have a super good front mount it should keep it fairly cool, but then again like i said also if i can get a good years use out of the twins chances are ill be single or upgraded twins within a year or two anyways..

heidihi

do you think that possibly rx7 store upped the fuel pressure to keep duty cycle down on the injectors? that being said what is the stock fuel pressure? 42lbs?

Mahjik

iTrader: (1)

heidihi,

The other thing to consider is that these dyno charts/numbers you see are typically not what people run most of the time they are driving their cars. I have a buddy who dyno'd 359rwhp on stock twins with a ported motor and the Pettit ECU (which means stock injectors). Now, that was at 15 PSI which he only ran every now and then.

If you are only looking to run the higher boost every now and then, the stock injectors can definitely do it providing the rest of the car can (i.e. good charge temps, good ignition, fuel pump able to supply the demand). If you want to run that kind of power daily, then increasing the injectors should be a must.

heidihi

my diving habbit with this car will be one day a week, as long as weather is nice that day. My car very well could sit in my garage for 2 weeks before i get to drive it. and during winter roughly early november till late march my car will sit in my garage..

so basically my time frame for driving this car is april till october, and then it only will be driven on very nice days.. if it looks like rain she will sit at home.. im very picky on driving it since its my nice car and i put too much money into it already..

i thought about the pettit ecu many times but then again i have the pfc and commander and id much rather just have a tune done for my car exactly.

thank you Mahjik for the info tho man! do you know what the stock fuel pressure is anyways tho? I am curious about that? cause maybe if i were to runt he stock injectors but up the fuel pressure 10 or so psi it will give me a lil safety margin.. not that im going to do this, but its an idea.

Mahjik

iTrader: (1)

Idle pressure is around 38 PSI. I wouldn't just increase the pressure across the board. If you really want to increase your fuel pressure, look at a Rising Rate Fuel Pressure Regulator which will allow you to increase fuel pressure at a higher than 1:1 ratio with boost.