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Reynard
June 9th, 2016, 12:11 PM
This is well out of my wheelhouse... a good friend owns said car and it has an electronic boost control installed. The engine & intercooler are bone stock but of course it has an aftermarket exhaust (not sure the brand/model). He is wanting to know what is the safe max boost he can run and doesn't trust all the internet experts. Well I trust you guys so I was wondering if anyone here has any experience & could give me a reliable answer I could pass on.

Thanks!

thesameguy
June 9th, 2016, 12:46 PM
Safe boost is factory boost. :)

Really, the only way to safely move beyond that is with feedback. Tuners make big bucks eeking out that extra performance by watching feedback on a specific engine and making adjustments - a level of detail manufacturers just won't engage in. Everything from fuel quality to ambient temperature to build variances will affect performance. I don't know much about the Evo, but if it has a wideband O2 sensor I'd encourage him to get a monitor on it - if it doesn't, have one installed and monitor it. I would probably also consider EGT, but ultimately that's probably less important the mixture. With that information, you can start slowly ratcheting up boost until you find yourself in the DANGER ZONE!!!!

IME, typically anyone can add 3-5psi to a factory tune without consequence, but I would really encourage investing in the right tools before making WAGs. :D

Godson
June 9th, 2016, 01:35 PM
Just take it to a reliable and well known tuner in the area. THe e36 BMW guys are known to run 8-10psi on stock internals. I have no idea on the Evo. I could ask a buddy of mine who would know, but I don't see him on a super regular basis.

Random
June 9th, 2016, 03:29 PM
We're the internet experts, don't trust us. :p

Peak stock boost* on an Evo VIII is in the high teens, Tyler. :) (Peak boost on a FiST is 22ish, FWIW).

Individuals cars vary enough that it's definitely worth taking the specific car in question to a reputable tuner and doing some data-logged dyno work.

*from the factory. As opposed to max boost, which would be what you could run in a given car.

thesameguy
June 9th, 2016, 03:40 PM
Look, if I can run 20+ psi on the XR and the SPG, a fancy shmancy Evo whatever should be good for 30+. That's all I'm saying.

Random
June 9th, 2016, 03:47 PM
Tim had a customer's Audi 200 wagon doing boost spikes to 32psi (frequency valve was busted)...he said it was a rocket ship. :D

thesameguy
June 9th, 2016, 04:08 PM
THE INTERNET HAS SPOKEN!

:lol:

CudaMan
June 10th, 2016, 11:21 AM
I don't know about EVOs but on some cars (FD for example) a free flowing exhaust with the unmodified ECU will cause a lean condition and potentially do damage to the engine.

A dyno tune on a programmable ECU is the right way. :up: Not always feasible though. Can the EVO ECU be flashed? The 350Z is easy, just buy software and a cable. MR2T? Gotta buy expensive hardware, wire it all up, etc, then find one of the probably few tuners who still knows how to work with this old stuff. [Still holding on to my pipe dream of ~40 extra hp and torques someday - why don't I just do it? I digress.]

A tuner who knows EVOs well (and is reputable) will be able to help the car owner judge risk/reward goals when finding a max boost number.

Reynard
June 10th, 2016, 05:08 PM
Thanks for the input guys. A bit of miscommunication on my part I found out that while he was concerned about what was a safe maximum, what he really wanted to know was what the stock psi level should be. :o So I was able to d/l a factory service manual and get that info easy enough. Yeah he's not too internet savvy. ;)

He'll get a kick that you replied though Cuda, he watches all your races thanks to me. :cool:

Jason
June 10th, 2016, 05:27 PM
We're the internet experts, don't trust us. :p

Peak stock boost* on an Evo VIII is in the high teens, Tyler. :) (Peak boost on a FiST is 22ish, FWIW).

Individuals cars vary enough that it's definitely worth taking the specific car in question to a reputable tuner and doing some data-logged dyno work.

*from the factory. As opposed to max boost, which would be what you could run in a given car.

Not all FiST's ;)