hello guys, my buddy upgraded his 93 rhd stock turbo setup to the Night Sport Turbos, with no other mods, whats happening now is the he.. spiking boost to a bout 11-12 psi around 4500-5500 rpm then just dropping off, just start to buck and backfire, or even when trying to excelerate hard, it just dies, false flat on it face, we have tried swapping the wastegate diafram, to see if that would help control the boost spike, even test TPS, sysyem, everthing checks, good. now that why iam here, what does he need to invest in to get this car making power again,, like it did before the new turbos.... would bov help,fuel management system, iginition system upgrade,?

 

It sounds like he doesn't have the proper boost control and/or ecu for these turbos.

Dave

 

anyone out there running these turbos or somthing similar that can give us some advise on what to try next, dont want to start spending too much on uneccessary upgrade...

 

List your mods if you want help...

 

Sounds like might be a mistake with installation, that's the first thing I'd check.

 

Yea, sounds like a vac line or something got switched or is still disconnected. I would check all of them again. Are you still sequential or non?

 

is the car even tuned?

 

Installing upgraded turbos and blowing your engine because it's not done right is what I call unnecessary.

To handle turbos like that you need a boost controller and/or a boost gauge. Otherwise you're flying blind and bad things can happen without warning.

Dave

 

all you guys have very good points, iam not a rx7 or that intuned with turbo setups my self, but all what you guys are saying is what i figured he needs, he bought the car with bad turbos, so i guess he figured buying these turbos {sequential} was going to be close enough to stock that he didnt have to change anything.. wrong...
he has no upgrades what so ever, no tune, no chiped ecu, no injectors, no boost controller,just got a boost guage nothing, ok, so now we know that, assuming all is assembled correctly, what would be your guys first step to solve this dilema... me personally i told him to get a boost controller,guage and bov... about tuning, iam a Honda guy, i know about programs/chip that i need to get what i want out of and engine, but i was under the impression rx7 ecu tuning is a little different,, can you guys fill me in... thanks

 

For a stock car you should be at 10psi max. Using the boost gauge will tell you this before and after installing any mods. If you stay at 10psi you will have enough fuel. BOV will not help/hurt so don't install one unless you want one.

You can install a couple mods in most cases before boost moves above 10. I'm guessing that the Knightsport turbos are pushing boost above 12 right now. Then it's time to install the boost controller to dial it back down there.

Dave

 

you guys have any suggestions on the most economic PFC, I should look in to...

 

also just another notes, his fuel mpg sucks, he going through a tank every 3 days, iam not really sure why it would be high since he cant really accelerate or even run a higher boost level... any thoughts... the only theory i have is that, the car runs fine at higher speeds/ rpm as long you dont step into it, maybe the fuel delivery is off for the untune ecu at the boost hes running...

 

Is the car throwing a check engine light or any sort of codes?? Sounds like the ECU is in safe mode and just dumping fuel. Try to reset the ECU and see if that helps.

 

Look for loose or unplugged vacuum hoses. My guess is that he's bouncing it off of fuel cut on a regular basis or it's in limp mode.

 

mmmm interesting limp mode? what is that... is that the same as safe mode? how would i go about reseting the ecu thanks guys..
quick qestion, why would the ecu dump fuel in safe mode, wouldnt it cut fuel off to save engine..? just wondering

 

What kind of mpg is he getting? And what kind of driving? Rx-7's aren't Honda's you know

 

lol haha, iam not really sure on the exact numbers, but i would think going through a tank of gas every 3 days would be reason for concern, regardless of what your driving... as for driving style, he cant really do anything to burn that much fuel, cant burn out,drift, cant do any donuts, cant luanch hard, nothing... he can just drive, he actually does a bit of high way driving to work, but that should help his mpg...

 

FDs can get 15mpg in general driving and be perfectly normal.

Fill the tank, zero the trip meter, drive it down, and fill back up. Divide the trip meter by the fill-up miles and you get MPG. Do it several times and you have some useful data.

"I need to fill up every 3 days" means little. My wife needs to fill 3x week and she drives a hybrid.

Dave