tundra2000

The guy i bought the car from told me he had it tuned at 15 psi but running 10psi for daily driving, but when i turn up the boost to about 11 or 12 psi, but then i get overboost. Why would it do this if it was tuned so it got me thinking that maybe it wasn't tuned because some people told me that if it doesn't lean out toward the end then it's not tuned, when ever i step on the throttle and stay in it the a/f ratio stays in the green but when i let off the gas it goes lean. SO is it tuned or am i missing something?

and by the way i don't have a missing link, would that cause it to think it's overboosting?

boostedeg302

First off, you cant change the boost pressure without re-tuning the engine. So it may be tuned on 10 psi but if you up the boost, it will no longer be tuned for the correct scenario. The best thing to do, would be to get it tuned yourself so you know for sure what is going on with your car. The worst way to find out the car isnt tuned is to blow it up. The second thing is it sounds like you are using an a/f guage which is narrowband. The only way to really read your a/f ratio is with a wideband. The one you have now is just a show of lights. If you wanna run over 12psi, you will need a bigger map sensor as the stock only reads to 12psi. If this was my car, I would grab a 3 bar map sensor and get a reputable tuner to tune the car. He should have his own wideband so really there is no need for you to have your own unless you have the extra cash. Another thing you can do is take the ecu out of the car and open it up to see if it is chipped. If not, then your not tuned.

tinctorus

Why couldnt he have 2 different tune/fuel maps??
On the srt-4 I had I was running 2 different tunes and so were NUMEROUS other guys

We have have a tune for high boost and a tune for low boost that changed the fuel maps and numerous other things

boostedeg302

He stated that he simply raised the boost. In order to run a different tune, you would need to flip a switch or something of the sort in order to change tunes. Since he did not do that, the fuel map would not change.

dpetro1

well he said the car was tuned for 15psi but dialed back to 10 for daily driving, so technically he sould be tuned safely to 15psi wothout changing anything.

OP, a few things...
1. when you say you are getting overboost, what do you need. is the CEL coming on? or is the car bogging out from boost cut controlled by the ECU?

2. you should not use a missing link when tuned on a chipped ecu.

3. as mentioned above, it sounds like you have a narrowband o2, which cannot accurately display a/f ratio.

4. you cannot properly run 15psi unless you have an aftermarket MAP sensor. the oem sensor can only read up to about 10.5psi before it reaches maximum voltage.

Are you running and obd1 ecu? If so, my advice would be to open the ecu and see if it has been chipped. The ecu should have these components installed http://www.phearable.net/images/ecusocketingins.gif

If it is chipped, you should have a tuner do a new tune so that you know everything is running properly.

If the ecu is not obd1 or is obd1 and not chipped then the car is not tuned properly.

tundra2000

Yeah when i hit overboost the CEL light will come on, and i will check the ecu latter on.

dpetro1

well then my bet is that the ecu is not chipped and the car is not tuned properly. get that sorted out and until then do not boost the car.

turbociv910

srt4s are srt4s, not honda b series bud.

take it to a shop

tundra2000

Doesn't the stock untuned b20 redline at 6700 rpm? Mine right now redlines at about 7500 rpm.

boostedeg302

+1 pretty much what I said

boostedeg302

Srt-4 have a much different way of tuning then a honda. They can adjust the tune accordingly when small changes occur. This is still limited but a honda ecu pretty much runs one setting and doesnt adjust on its own.

dpetro1

please dont redline the car until you confirm if it has been tuned.

tundra2000

I took the p28 apart and this is what it looks like, So is it tuned?

2k.civic.si

something tells me the stock map sensor is still in the car and the 15psi was bs
the ecu is socketed and chiped but that still doesnt mean its tuned
i can tell you this much for certain....it has a hondata s100 in it

skuded

if that is s100 good luck finding someone to get it tuned, i dont know of anyone around where i live that still tunes s200 even

dpetro1

as stated above. the ecu is chipped/socketed with s100. so it may have been tuned. if the car is on a stock MAP sensor you are probably getting a CEL becauase the hondata tables were only expanded enough for the stock map. if you want to bgoost higher you need to go with a 3 bar or similar.

EG6 Love

iTrader: (1)

you will read 'lean' when u get off the gas. thats normal.

tinctorus

No **** dude no need to be an *******...My point was that there IS a way to have 2 different fuel maps, one for high boost and one for low boost and I was asking IF he had that

No need to be a smartass, I may be new here but I aint new to cars OR tuning/building them