# What's limiting by boost....detonation?



## Player1 (Apr 3, 2004)

*What's limiting my boost....detonation?*

I've got an 86 turbo with a manual boost control a K&N filter kit and a HKS cat-back exhaust . I can only adjust it so far until the engine breaks up or studders a little. It doesn't sound like like pinging so is this detonation? When i dial back the boost control a little it goes away. I always use high octane gas. Would a downpipe or colder plugs allow me to use more boost?


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## asleepz (Feb 24, 2004)

how much boost are you pushing until you get pre-detonation ( and yes that's what it is)

I wouldn't go over 14PSI MAX


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## Player1 (Apr 3, 2004)

*How much boost?*

This is a really low tech answer but the manual boost has a dial you turn. The less threads left showing the more the boost. I have to keep about five threads showing to keep the detonation down. I don't have a boost gauge except for the stock one on the car. The gauge goes past 7 and into the red.


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## asleepz (Feb 24, 2004)

Whoa Dude!!! You Need An Acurate Gauge Before You Start Tuning!!! Rip That Thing Off Before You Blow That Baby Up!!!!!!!


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## Zen31ZR (Mar 24, 2004)

Yes , definitely get a real boost guage. 
I'm running 15 psi with no issues , so you must be spiking quite a bit beyond that. I'd say you were getting into some MAF over-run , which will probably happen around 17-18 psi , I haven't tested that theory yet , though. Be careful , the studdering can be a side effect of the knock sensor wigging out because of knock and pulling timing into the negative. You may or may not actually hear the knock , depending on if the knock is in a cylinder near the firewall. Be careful with that , because knock WILL kill the stock head gaskets , for one , and heavy knock in even one cylinder WILL melt the piston.


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## JAMESZ (Mar 12, 2004)

Until you can measure how much boost your playing with take off the boost controller. You could do serious damage to your engine if you do not.


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## Player1 (Apr 3, 2004)

JAMESZ said:


> Until you can measure how much boost your playing with take off the boost controller. You could do serious damage to your engine if you do not.


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## Player1 (Apr 3, 2004)

Thanks...I'll dial back the controller until i get an accurate gauge.


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