nathan_s

Ok so when I speed up my boost goes up like it should, up to 16 PSI but there seems to be no effect on the motor like it doesnt speed up off the boost or anything so I let off so that the boost can be released. Since the boost builds I figure there cant be a manifold issue or a BOV issue because boost wouldnt build. It seems liek fora moment the car starts to pick up on the boost but then it doesnt speed up any from it. The only thing I can think of is an isuue with the Wastegate. Help plz !!

Rx7_Nut13B

iTrader: (1)

If you are building boost then it cant be the wastgate, What are your AFR's under boost.

If you are overly rich then it will bog, it would have to be overly rich because if you where lean at 16psi the motor would be gone.

Jack

iTrader: (2)

Sounds like something in your exhaust is restricted, broken cat etc...

Project84

First question that comes to my mind: Is the vaccuum/pressure hooked up to your wastegate properly? Something has to tell it when its time to start bypassing the exhaust around the turbine.

Also, is your setup stock or do you have some thing aftermarket? Has it worked and then recently started acting up? Or has it been acting like this only since the last time someone stuck their hands under the hood to do some maintenance?

nathan_s

Aftermarket. T04S turbo, Street ported, 3mm apex seals, Power FC, 550 Pri 1680cc sec, 3 in downpipe, stock exhaust, Greddy RS BOV, MOP deleted, AC and power steering del. Block off plate job done. And I have a vacuum line running from the Manifold directly to the waste gate. The other vac line runs to the BOV, Guage, and Map sensor. In like 4th gear the car seems to respond better but then in 5th at about 3000 when I hit it the Boost goes up but the car just kinda starts to speed up. AFR is lower part of optimal. Possible its getting too much air and is leaner than should be? One of the guys at RX7 store did my mapping for the setup in my PFC. But its like it spools up and I get boost, but then the car jsut kinda starts to speed up and it worse in 5th than 4th. AFR drops when I hit it but then starts to come back up and hovers between edge and middle of optimal. But then like I said, still doesnt seem to really speed up.

Project84

Hmm, sounds strange. You build boost, but the car does not respond to it? I'd get with who ever programmed the ECU and have them see what you are experiencing and then check the spark timing, fuel delivery, etc to see what is up. Have them ride with you and see what is going on; data log the drive if your ECU has the capability to do that. Then you can print it out or look at it later.

nathan_s

Suppose its possible I need to replace the gaskets to my intake and side manifold and re torque the bolts? possible its losing the boost there ?

JasonDowney

iTrader: (1)

If you had that bad of a leak, which isnt really possible, you wouldnt be registering 16lbs of boost. I just put on a turbo and was boosting to around 17lbs, but it wasnt fast at all because I was dumping fuel into it. It just sounds like you need it tuned better.

Rx7_Nut13B

iTrader: (1)

Do you have a copy of your map that i can look at, this all seems to be fuel/timing. The wastegate is working just like it is suppost to, if it wasnt then you would be in the 16+ range. All the wastegate does is keep the boost at a level you want, and it is doing its job.

When you have to much fuel or to retarded under boost it really doesnt help power, when you are tuning a car you want to get to the edge of safe then come back a little from it.

When you said "AFR is lower part of optimal" you answered your own question, this means that you are in the 9-10.5AFR when you need to be in the 11-12AFR

nathan_s

Uhm aside from writing it all down by hand...no. Which map would you want to look at ? and are you saying its running lean then ?

Rx7_Nut13B

iTrader: (1)

Well by your reply I can tell you don't know much about Air Fuel Ratio's and tuning.

When I said "9-10.5AFR when you need to be in the 11-12AFR" I was saying that they bogging and low level of response is most likely caused by a overly rich condition or it is retarded to much.

10AFR= VERY RICH
20AFR= VERY LEAN

14.7AFR= Stotch

11-12.5AFR= Under boost
14.7-17AFR= cruising

These are just Ideas for the AFR's

Project84

Stoich, not stoch. But he is right. For gasoline, a stoich mixture is 14.7 to 1. More fuel in the mixture changes the ratio, bring it down to something under 14.7:1 leaving you with a rich mixture. If you have less fuel and more air, your mixture changes to something greater than 14.7:1 creating a lean mixture.

As for your maps, most aftermaket ECUs or piggyback devices just provide humans with graphic interfaces to the engine programming. They also usually have a way to download the current engine programming as a file so that it can be transported to other computers and viewed by other people. Someone who is familiar with the engine and the type of ECU running the engine should be able to tell you what settings the program needs in order to run the engine properly.

nathan_s

I can view the map on my commander.. thats why I said by hand. Secondly it seems to be closer to lean than rich. Its still optimal but closer to lean than centered. And no lo. idk much about that stuff, Im nota tuner.

nathan_s

I guess my next question then would be Are there any tuning shops in vegas that I could go to?

Rx7_Nut13B

iTrader: (1)

Well if it is lean under full boost them you have a SUPER retarded timing in the boost area. If it didn't then your motor would have all ready blown up.

You do have a wideband, what is the AFR at max boost?

With a PowerFC you need a Datalogit to pull the maps off the computer.

nathan_s

Its not lean, its just kinda closer to it than rich, no I dont hava wide band. I dont have the car goin off the o2 sensor. I turned that off in the options. Should I go ahead and turn it back on? And as far as it being retarded itsa T04 so usually it takes a sec to spool up as it is...and I dont hava datalogit.

Rx7_Nut13B

iTrader: (1)

Well, how do you no where the AFR is then, you say that it is closer to lean than rich. WHERE DO YOU GET THIS DATA???

The O2 setting is only for cruise, just leave it off.

The turbo size and spool doesn't have much to do with timing. It will decrease your spool time if it is advanced.

What I am trying to say with the timing is simply this, if you have a really retarded timing map, then this will happen

(This below is hypothetical)
10psi of boost + 13 degrees of timing@Full Boost= 300hp
10psi of boost + 5 degrees of timing@Full Boost = 230hp

16psi of boost + 13 degrees of timing@Full Boost = 400hp
16psi of boost + 5 degrees of timing@Full Boost = 280hp

The timing has allot to do with the HP output, but

DON'T PLAY WITH YOUR TIMING WITHOUT A WIDEBAND O2 SENSOR TO MAKE SURE THE AFR IS SAFE

nathan_s

I do have an AFR Gauge hooked up and its on my dash. So I do see the AFR Ratio.

nathan_s

Looks like im gona buy a wideband then.

Rx7_Nut13B

iTrader: (1)

Good Job!!

That O2 gauge is probably a Narrow Band gauge so it is mostly useless.

But the good news is you can wire the wideband into the narrow band gauge and it will be as actuate as the wideband