Boost Cutout

[moparturbo84]

I got my exhaust put on my car today. It is 2.5 inch with no cat or muffler on my 84 New Yorker. After I got it installed I floored it and it pulled hard to 35 when it the engine started cutting in and out. I guess that it must be hitting boost cutout but I'm not sure. Can anyone tell me for sure?

[oldgregg]

Sounds like it.

When you open up an exhaust you also gain a few lbs of boost.

[moparturbo84]

What is the cutout on a stock computer? What about on a MP computer? Would a new computer keep it from hitting cutout???

[sup3rfr3ak]

stock t2 computer cutout is 14.7 i do believe

[OmniGuy123]

Quote:

Originally Posted by sup3rfr3ak stock t2 computer cutout is 14.7 i do believe

All 2 bar computers made by mopar wether MP or otherwise cutout at 14.7PSI, as that is the max of the 2 bar cals. It just might take you LM a little while to adjust to the larger exahust?

[Marcus86GLHS]

"......I guess that it must be hitting boost cutout but I'm not sure. ......"

do you have a boost gauge and if so what's the reading when the engine cuts out?

[iTurbo]

I had to gap my spark plugs down to .030" to prevent misfires when I was running open exhaust..

[moparturbo84]

I dont have a boost gauge. I thought I heard from somewhere that 84 cals cutout at like 10psi but I might have heard wrong. When it happens it cuts out for a second and then kicks back in and then back out and so on.

[moparturbo84]

The power loss light flickers on when it cuts out. I have put 75+ miles on it since then and cuts out every time you jump on it. It is hard for me to believe I doubled my boost from swapping my exhaust. I just want to identify the problem.

[anonymous_user]

So, you're doing modifications without a boost gauge. I suppose you don't have any gauges telling you if your air/fuel is OK either? This is step one. Not optional. You don't know what is happening without this infomation.

Boost cutout - it feels like you hit a brick wall for a second. The car is accelerating and BAM spark and/or fuel is cutout NOW. Then, BAM, it takes off again.

First, check to see that there is a restrictor in the line to the wastegate. Without one I can see uncontrollable spikes. You could play around with different size restrictors and see what happens. This would be the cheapest thing to do.

Best thing would be to install a Grainger valve and control the boost yourself. Of course this is AFTER you've installed your boost gauge and A/F gauge. Very important and very cheap - for example, here's a $6 boost gauge:

http://www.grainger.com/Grainger/wwg...mId=1612699699

[tryingbe]

Quote:

Originally Posted by moparturbo84 I dont have a boost gauge.

Keep doing it, I love to see your engine melt down.

[Marcus86GLHS]

yes you should get a boost gauge, and an a/f ratio gauge, pronto.