N/T Boost Levels

[aspekt9]

What is preventing me from running 15psi on the 14b with the given mods in my profile on my N/T to turbo swap? I know detonation is the determining factor so what can be done to minimize it to the point where I can run a decent amount of boost?

 

[bagged420a]

i wouldn't run that on your stock internals. you'll need to get lower compression ratio pistons

 

[gijoe985]

I second that. I don't know about how the internals vary on a nt vs turbo, other than no oil squirters, but that's not a big deal. What I can do is some math for you, to help paint a picture.

1g NT= 9:1 compression
1g Turbo= 7.8:1 compression

So the NT is 1.154 times more compressed. So running 15psi would be more like 17+psi. And as far as I know, 17psi is starting to push it on stock internals, especially if you don't have the supporting fuel mods.

I guess, if you figure you have the same mods as a guy running a turbo 2g at 17psi, then you'll be ok.

 

[aspekt9]

Is a good tune and timing control the key to control detonation? I've heard the N/T pistons with the higher ring lands can handle the power fine it's when detonation occurs that they crack and blow up.

 

[JusMX141]

The thickness of the amount of metal between the piston crown and top ring groove are different between the non-turbo and turbo cast OEM pistons. If you run excessive boost on stock cast non-turbo pistons, they will break.

http://www.dsmtuners.com/forums/420a-turbo-conversion/141210-non-turbo-pistons-cant-take-boost.html


Higher compression Pros:

- More off-boost torque.
- Less turbo lag due to increase exhaust energy.
- Less boost required to achieve the same horsepower as lower compression.

Higher compression Cons:

- Higher octane fuel required to prevent knock.
- Lower peak boost threshold without PERFECT tuning.
- Water / Meth injection use almost mandatory to run over 20psi on pump gas.

 

[eclipse94turbo]

dude if i was you i wouldnt go over 10 psi.id run 8 at most.thats a safe level now if you run meth and or race gas id say 10-15 psi would stll be iffy.now if you dont care about ya motor run ova 10psi but have a wreaker on speed dial man trust me.maybe a lil nitrous would get you that lil extra power you need.

 

[gijoe985]

Is a good tune and timing control the key to control detonation? I've heard the N/T pistons with the higher ring lands can handle the power fine it's when detonation occurs that they crack and blow up.

I can't input about stronger ring lands, but concerning detonation-

Tuning and timing does control detonation, but it does only go so far. Read this first:

explaining knock and how to get rid of it

That will give you an idea bout what detonation is, what causes it, and what prevents it. You mentioned timing is a key. Well increased timing can increase power, but eventually it will create detonation. Same with boost, more boost = more power, but it eventually leads to detonation.

Hope that all helps.

 

[aspekt9]

Thanks for the link, it helped out a lot.

 

[92tsifwd]

I would say 7-9psi for 91 pump. I have run 13psi with no problems on 100 octane and turned 14.0 at the track. It ran great till my boost controler malfunctioned and spiked to 21psi & spun two rod bearings and broke all four piston's ring glands on my 1g 7 bolt.