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max psi/stock l28t


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Guest Anonymous

Whats the max psi of boost I can push my stock turbo on my stock engine with no modification.max hp?

What is the max boost the stock ecu can hold.

 

Thanks!

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Originally posted by FreakZ:

Whats the max psi of boost I can push my stock turbo on my stock engine with no modification.max hp?

What is the max boost the stock ecu can hold.

 

Thanks!

Do a search on this, and you will find the question asked and answered multiple times.

 

In short, the stock turbo can be pushed to 18psi, but is hugely inefficient at that level. The stock ZXT ECU can also fuel for that with a mild injector upgrade (370cc), but driveability is terrible. But answers to these questions and many more can be found in the archives.

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With no mods, I'm assuming you mean no intercooler, stock injectors and stock fuel presure, stock exhaust system, and so on. I'd say you're safe to about 9psi without any problems. Still good to get an air/fuel ratio gauge to make sure you're not running lean.

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Find a calculator online to find the maximum output capability of your injectors. I'm more familiar with pounds per hour instead of cc's, so I don't know of any myself offhand.

 

I assume thats what you mean with "no mods", you will need injectors at some point, an intercooler would be nice (pump gas sucks), most guys grab a better MAF, exaust, etc

 

If you plan to road race or do more than drag with the car, you will want to keep injector duty cycle low, 65-75%.

 

Good luck

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Tony is right. If you wanted to squeeze more then a rising rate fuel pressure regulator would help get the last bit of fuel out of stock injectors. Then next step would be larger injectors; I/C;Larger TB;on and on and on. Your wallet is your only limitation!!!!!!Be sure and get a Air fuel ratio gauge to analize your mix!!

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You might do a serch and check out past posts on correct year 240sx tb. I believe the 300zx TB is around 55mm. the the 240TB is 60mm. Also I think the 300sxTB you may not have to build a 1" spacer(it has correct stack height) but you need to do a search on that to be sure. You'd be amazed at what information you will find by doing a search. SuperDan did a great Job on this websight! hail.gif

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  • 2 weeks later...

As usual there are alot of unknowns, that need to be known.

1. What type intercooler?

2. What size injectors?

3. Did you upgrade to larger exaust?

4. Did you upgrade your fuel management systum or using stock computer?

I believe Scottymiz has gone the farthest with regards to maxing out somewhat stock systum. You might read past posts Scotty has made before last spring when he installed his larger turbo 2thumbs.gif

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Originally posted by Rags:

I'm more curious to know what is the hightest boost levet someone has run on a stock long block that has an intercooler and has the fuel system upgraded.

 

Joe

Shane has run 23-25 psi with a T3/TO4 hybrid turbo, upgraded fuel system, and a JWT ECU. That's the most boost on a stock engine I know of.
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I stand corrected Sleeper; I misread the original post. In my mind (before my cup of coffee this morning smile.gif )I was thinking of what max on stock "components" with only the addition of I/C & larger injectors (around 14lbs). Not max with max upgrades on "assessory's" using stock block!

Believe your right concerning Shane. I don't remember but did he O ring his block?

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Guest Zcarsmakemyheadhurt

12psi broken head gasket for sure, if you swap the gasket to a fel-pro you could do something exciting. Ive boosted 18psi on race gas with a good clutch 3.90 gear and Mcquery G60 13.60 for sure. Enjoy the ride.

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I don't think Shane did much of anything to his block other than just being in sound condition. He has switch to a SDS system and is making a ton of HP. burnout.gif If you look down the page some you'll see a post be him with his numbers. Also check out his intercooler it's one of the best looking units out there and I think he got it for a good price. ;)

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Originally posted by Len:

I stand corrected Sleeper; I misread the original post. In my mind (before my cup of coffee this morning smile.gif )I was thinking of what max on stock "components" with only the addition of I/C & larger injectors (around 14lbs). Not max with max upgrades on "assessory's" using stock block!

Believe your right concerning Shane. I don't remember but did he O ring his block?

:D

 

No, as a matter of fact, he never cracked the head off the block out of the junkyard...

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Guest Tom Scala

I've hit 20psi a couple of times on my 78 80,000 mile n/a block P90A head,new stock Nissan HG with new turbo bolts with no ill effects (& no detonation). It's just been for short bursts on the street, I wouldn't try it for more than a few seconds at a time though without a full load of race fuel. I can run 14-15psi or so all day on pump gas and intake temps stay down pretty well at that level with the smallish Spearco IC I'm running.

t3/t4oE

SDS

420cc injectors

2.5" mandrel bent straight through exhaust

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Boy that just dashed my thoughts concerning the need to O ring above 18 psi! We got some mighty good engines I must say!!!!!!!!!!!!!! b_hand.gif

Shane if you read this; thanks again for selling me that NPR I/C. Just about have it installed!

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