so just got my car back from a tune. and in all gears 1-4 im hitting 25 psi and holding. but once i shift to fifth it stops at 15 and flutters. here is a video. im using a ebcs grimmspeed. Tuner didnt have room to tune it in fifth. could this be a tune issue?

 

anyone?

 

I would call the tuner and ask him to look over his boost settings. It seems like a tune issue because if it were a mechanical issue you would be hitting 15 psi in all 5 gears. Most people have issues overboosting in 5th. This is the first time I see a drop in boost pressure.

-pal215

 

What's your speed and rpm when your going WOT in 5th?

 

I was told by a fairly reputable tuner that boosting in 5th gear is asking for big problems.
Maybe someone can elaborate.

 

yes when i got my car tunned my tuner turned off the boost in 5th gear cuz he said the load would be to high for the stock rods. I personally didnt like that so I borrowed a friend tatrix cable and changed the boost settings. I just coppied the boost setting from 4th gear and added it to the 5th gear colomn

 

Turned the boost off in a gear? How do you do that?

 

i dunno lol. Ill try to add some pics when i get off work of what my map looks like.

 

Heat + Load is what ruins rods. If you're running a fairly conservative tune that does not allow for so much heat, aka, a bit on the richer side, you can afford to hit full boost in 5th. It's not the best choice in the world, but I would at least want to have that option.

-pal215

 

I can also confirm my tuner advised the same thing. Stay out of boost in 5th unless you want blown rods. Which apparently is much more of a concern on e85, but still true for pump gas too.

 

You guys need to find different tuners. If you'd like me to elaborate I will do it through pm's, not on open discussion.

 

How so? Its common knowledge that you shouldn't boost at low rpms due to load and 5th gear is a pretty low rpm gear. I would appreciate an explanation via pm if you dont mind. Maybe there is something I dont know.

 

Pm'd you winston

 

I would like to know as well. Post for everyone to see. High loads in fifth + boost will window your block and is a rod killer. This is known as well as to keep torque around 400 on stock rods. If you do copy the tables for it i would never go wot unless you are at red line in fourth.

 

Thanks for the proper explanation reaper. Makes sense.