Ok, so i got my rx7 about 2 weeks ago. I just installed a catless turboback exhaust and an intake. It makes the turbo respond great. I have a fuel cut defensor on the way because obviously i hit fuel cut. im just driving her easy. stock compared to now is rediculous in terms of turbo spool/lag, its MUCH better, you can tell it really wants to pull. Im getting some gauges in a week or so. I have a turboxs manual boost controller on it, but its fully turned down, and still doesnt help keep boost down. So im thinking or figuring its the wastegate spring? because it spools while standing still. i have been getting really bad gas mileage also (about 11-13 mpg just driving it around any help?) anyway. Im trying to see what i can get out of this car with a few mods. I dont mind spending more money on it. I just want to know what is considered safe. and what steps to go to. walbro pump...injectors...what do you feel would help me? i figure 300 flywheel horse power on the stock setup shouldnt be a problem. thanks for your time in advanced! I figure if i have a t4 larger turbo, i'd need to redo the seals and maybe port the motor a little...

Josh

 

dont go over 8 psi, at all, keep towards the lower boost. The next thing to do, is get a haltech, standalone, becuase for that much hp u want a standalone, and get a bigger turbo, port and polish (streetport) 255lph fuel pump, 720cc secondaries.

id say keep it close to stock before upgrading everything and get a nice suspension for the car. Itll make it more of a fun to drive.

 

if you put the fuel cut defenser on chances are you will blow the engine. it can't take over8-10 safly in stock form.

first thing you need to do is install the boost gauge. then buy a bigger fuel pump like the walbro and search on how to rewire it.

now put the FCD in and carefully boost while watching the gauge. if it goes over 11-12 let the hell off. this is your new safe limit.

chances are it will still go over this. at this point either you can port the wastegate to bring the boost down (take off turbo and make the holes bigger) or you can get bigger injecters to hander the higher boost.

the boost controller can only raise boost, not lower it. the higher boost is perfectly normal (however not safe). the only way to lower it is to port the wastegate or restrict your intake / ehaust back up.

 

Boost contollers cannot reduce base boost levels.
The exhaust and intake increases base boost levels due to better engine efficiency.


http://fc3spro.com/TECH/FM2W/power.htm


-Ted

 

Thank you very much, Im going to get the fuel pump, rewire it, and port my wastegate.

Josh

 

The only way to change boost is by changing the wastegate? please let me know if there is any other way. We installed a turboxs manual boost controller, but didnt work. Who ports wastegates? i have a 47,000 mile rx7...so i dont want to get rid of that turbo. Anyone know near Fort Myers FL (southwest FL) where to get it done? Im ordering guages (egt and boost) as well as walbro fuel pump. and i'll have it rewired as well.

Thanks for your time, the rx7 feels like it'll be so much more fun when i have all this settled and the problems fixed.

Josh

 

10psi all day long with stock injectors, stock ECU, and a fuel pump rewire. Oh. And it'll still run rich.

 

The wastegate opens via pressure. It should be fully open by 5psi.

A boost controller changes/bleeds off(depending on type) that pressure refernce so it takes more pressure to open that 5psi spring.

That's why you cannot lower pressure only raise it.
To lower boost you would need to get a weaker spring/wastegate.

Currently I push 8-10psi on my setup. This is all due to boost creep though(you'll learn about it). I have cleaned injectors and a Walbro. I HIGHLY recommend upgrading to 720 secondaries if you plan to go over 10psi.

Boost creep happend because the wastegate hole cannot bypass enough exhaust and it has to go through the turbine spooling it higher than desired.

If you want 300 hp you will need a turbo upgrade.
I think I've only seen one person hit close to 300hp on a stock turbo but I'm sure it didn't last long.

The stock turbo over 14psi runs out of it's efficiency range and it just produces more heat.

 

i've head that 680cc and fd pump will support anything the stock turbo can throw at it.

 

with my mods i hit 10 psi, and havent seen it go over that mark yet ... which is awesome, cause thats right where i wanted to be...im at a good standing point. ...

my wastegate is ported however ...