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What's the maximum boost you can throw at a stock DOHC 4? safely, anyways

I have done 22 psi on a t3 super 60

This is an old post I know, but just thought id ask......Hey minimonster, was that 22psi on a stock mx-3 1.6l dohc 4cyl? No internal work? Im currently running ~8psi on the stock SOHC 4cyl in my mx and just curious as to your setup...........plus im bored and looking allover the new ubb

With my 1.8 BP (swap) in my MX-3 i run 23psi last year with a
GT 35-40 R garrett .
No problem at all.
My redline was set at 9000 rpm.

Run : 11.28 @ 125

^ I think the guy meant how much boost on stock internals.

hotsiit wrote:This is an old post I know, but just thought id ask......Hey minimonster, was that 22psi on a stock mx-3 1.6l dohc 4cyl? No internal work? Im currently running ~8psi on the stock SOHC 4cyl in my mx and just curious as to your setup...........plus im bored and looking allover the new ubb

Yes it was a stock internal motor. But it had a great ecu on it.

So on a stock engine (1.6 DOHC) without any mods (stronger rods/pistons/bearings) you did 22psi??? That's awsome. Did you also leave the compression rate the same (9.0:1).
So in fact you can run everything under 22psi on just a stock engine??
One last question. I've done over 160000KM with my car, would this be a problem when turbocahrging it??

please note that 22psi doesn't really mean much. all that means is how much the turbo has to work to get to a certain point. running 15psi on a vj20 is different than running 15psi on a huge t3/t04. the bigger turbo flows more cfm, so it's psi level will be lower to achieve the same outcome. the more air, if compensated correctly with the proper fuel and spark, will create more hp. so you have to take into consideration the size of the turbo for each application. also....tuning is EVERYTHING!


drag323, what do you have done to the valvetrain to support a 9k redline? have you put it on a dyno to show it's still making power that high up? i know the turbo will still make power, provided your manifold/exhaust isn't choking it.(based on your times, i'd say no) just not sure if you'd be floating the valves that high up.

Stock valvetrain.

Ok I understand, but if I keep my engine stock, and I put a standard b6t turbo on it, how much psi can I boost than??
My father is always saying that I can't put a turbo on it, beacuse I will blow my engine. And how is this standard b6t turbo cooled? Oil or water.
Thanks

Ben

Hey RazorMX-3

It is all about tuning, most of the guys on here who have turboed their DOHC MX3 4cycl are running anywhere from 7-12psi. I currently run 10psi on a bone stock engine. Once you have proper management like a Link or Haltech standalone ECU, you could easily run 14psi+

Thx. So I wont have to change anything when boosting around 8-10 PSI. I am only lokking for 150-170 hp. Not the mega numbers all the guys are talking about like 300-400hp. But is the turbo water or oil cooled.
Thx

The stock IHI VJ series turbos found on the B6T, BPT etc are both oil and water cooled.

How much boost do the standard b6t's have??
And to come back on my question. Can I run 10 psi on my standard engine like osargeant said. My engine has run 160000. Won't I blow it??

I put a VJ-11 on my mx-3 with 140,000 miles on it. She had a weee bit of a oil leak. Lasted 4 months and I blew 2 pistons and a headgasket. I am now awaiting my B6T motor. I don't think running anything over 7psi is really a good idea on a high mileage motor unless you do a rebuild off all your seals and all. Thats just my opinion.