HELP!! SRT-4 Overboosting with 9r18

[kmskovenant]

I have stock srt-4. When i purchase predator, it was flashed with U7134-9r17.crom. When i flash it with 93oct tune, car was runnign great at 14 psi. Now i decide to update predator to 9r18.crom and car start to run with horrible overboost, i'm getting like 16psi on second and 3rd and 4th are 20 psi. Car become slower then it used to run at 14psi. I need help to go back to 9r17.crom tune which was avaivable on this site few weeks ago and now i cannot download it anymore. Only 9r18 avaivable which is works horrible for me. Right now i'm running stock tune which came with car. Anyone can provide me with link to download previous crom? You can downgrade predator croms, right?
Thank you.

[kmskovenant]

Found it..previous crom...so i shoild be able to downgrade back to 9r17.crom right?

Also wonder what cause these overboost issues?

[gizmodo]

It would be helpful if you posted what you have done to the car. Are all the vacuum lines setup as they were from the factory? Do you have any other type of boost controller?

[sfla_srt4]

Sorry to say but 16-20 lbs is not overboost... those are good boost levels, but only if your not lean on the afrs or have knock. I find it very hard to believe the car is "slower" on the higher boost too. Sorry I cant help on finding the older crom.

[duster360]

If 9r18 is "horrible", you ain't using it right. 19-20psi is what you want.

14psi is stock level and is reserved for little girls or your mom.

[kmskovenant]

It would be helpful if you posted what you have done to the car. Are all the vacuum lines setup as they were from the factory? Do you have any other type of boost controller?

It's a bone stock srt-4, all vacum lines are stock..turbo, wga, pcm..it's canadian srt-4. The only mod i have is AME short arm intake..and never had with previous .croms.

[kmskovenant]

If 9r18 is "horrible", you ain't using it right. 19-20psi is what you want.

14psi is stock level and is reserved for little girls or your mom.

it's a stock turbo, stock turbo supose to be limited at 18 psi or whatever after 18-19 become uselless? I even get 22 psi and car doesn't push any harder at all... it just doesn't run smooth as it did with 9r17. I don't want to blow my motor with 20 psi. 93 oct tune supose to be already tuned so you don't have to worry about anything running lean or rich since it's bone stock srt-4.

[gizmodo]

The stock turbo is limited to what the PCM is commanding of it. It can push more than 20psi without problems. I am guessing you are referring to people saying the stocker just blows hot air above 17 or so pis. That isn't true.

Are you saying it is spiking at 22 or holding 20? A 22 psi spike is fine. Do you have a wideband, if not you need one.

[duster360]

If 9r18 is "horrible", you ain't using it right. 19-20psi is what you want.

14psi is stock level and is reserved for little girls or your mom.

it's a stock turbo, stock turbo supose to be limited at 18 psi or whatever after 18-19 become uselless? I even get 22 psi and car doesn't push any harder at all... it just doesn't run smooth as it did with 9r17. I don't want to blow my motor with 20 psi. 93 oct tune supose to be already tuned so you don't have to worry about anything running lean or rich since it's bone stock srt-4.

No, no,,,a brief 19-22psi spike is perfectly fine, because with a stock turbo the spike above 18-19psi only lasts 1-2 seconds.

Get a wideband O2 sensor but until you do, you can use Knock retard as a guide so you "don't your motor". You should always datalog anyway but Here's a helpful thread on Knock. http://www.srtforums.com/forums/f384/kn ... ou-534338/

[kmskovenant]

Thanks guys.. btw with 9r17.crom i got 15psi spike and 14psi hold..car runs great..but with 9r18.crom spikes 20, holds 18 then when getting to redline it actually holds almost 21, suprised that it was increased but it happend on 4th gear. It's just too weird for me with latest update because stock or 9r17 don't really spike much for me...they spike almost the same amount of boost what they hold. I don't have wideband because i though why would i need one if i use canned 93 tune on stock srt-4, it's not like it's a custom tune.

[gizmodo]

You still need a wideband. All cars react differently. If you are actually worried about the engine, you would get one. When you do get one, make sure it is capable of logging.