Compressor surge under high rpm + heavy load
 

This is my first post I'm pretty sure.... So I'm a newbie do move this if need be

I posted this on the Facebook post however I wanted to post it here too just to get a wider variety of answers...

Let's see if you guys can help me with what's going on...


First off, hello my name is Kris and I am the proud owner of a freshly boosted 1.6 1993

Secondly, this is my first turbo car and I have no clue where to begin any diagnosing regarding turbos

Now the problem:
I just recently made the switch over to e85 and of course there are gonna be problems before tuning your ve table.... However , im experiencing compressor surge, not the whatever cool sounding flutter, but surge under load...

A possibility I was thinking was maybe I'm running too rich in that area of my fuel table...
However when I do a pull , the afr in that area is 11.5-12 . It's around 7PSI of boost, how the AFRs should be no?...

I'm not necessarily asking for a solution, but maybe more ideas on where to start in fixing this problem

To give y'all further details , I'm running a mspnp gen 2, base ignition map, and rx7 460cc red top injectors.....

Also if anyone running a similar set up could provide me with a screenshot of your WUE table, you would bless me 😁

Maybe a screenshot of your Accel enrichment graph too 😘

Why not datalog this and post it here? Save us all a lot of time.

Sure thing ! I'll do a pull and log it before I arrive at work tomorrow.

Maybe it's over fueling ? I'm not leaning out at all , so my injectors shouldn't be getting maxed...

Maybe post a video as well as tune? I'm not picturing surge under load.

I honestly wouldn't be surprised if it wasn't surge.. but I'll gladly do a pull on the way home after work. I'll post it tonight.

Actual compressor surge only happens under load. But i'm not seeing it happen in this scenario either. Require video for science! :)

It's much easier to get into surge with a big turbo and small engine. 1.6 is small engine. What size is turbo?

He's not mentioning that he is running E85 without having tuned for it, and he has a T25 off a SR20DET which admittedly isn't a very big turbo... His idea of surge under load was boost loss when he is trying to hit 7psi, which I think probably comes more down to intake leaks, or wastegate/electronic boost control if he has any, than anything else.

Lol. A 1.6 won't have surge issues with that turbo. Intercooler couplers make crazy noises when they leak.

Yeah... He made a post on the Facebook page and people tried to help him, but he just started saying yolo and that he wants to blow his car up

Which is another good reason why I ignore Facebook.

LMAO I'm hella dead 😂

It's really hard to hear , I'm suspecting my fuel pump is maxing out tbh , but if you watch you will notice that it loses power right at 4k and then when I go on to 5k it loses power again. It makes a nice little fluttering noise , kinda hard to hear with my rattling cracked dash

Thinking of switching back to pump gas , but regardless I want to know what is happening just so I can know what exactly happened the next time I experience this

Well, since you're running E85, you're going to need a lot more fuel. You're also not tuned for it. Surge is caused from air going backwards into the compressor and causing it to stall, making the stu-stu-stu sound. Misfires and closing the throttle plenum are the two surefire ways I can think of to make air come back out the intake. The fact that you are not letting off the throttle, and you are losing power, makes me think it is the former.

And you should listen to peoples suggestions instead of saying you know what you're doing when you clearly don't, or "lmao I'm hella dead" when someone tells you you already were told the answer - in fact, you just told them they were fat because it wasn't what you wanted to hear and started trolling

I mean I admit I did go a little crazy there yeah haha, I apologize for my childish attitude, but in my defense most of it felt a lot more hostile than what I received here(much appreciated by the way)

ANYWAYS

Sounds reasonable, but what do you mean by the former?
The car is currently going through Dyno prep so the tune is next , just looking for a reliable spot to get it tuned at

Do you have a flex fuel sensor or are you tuning for 100% E85 usage? If you are tuning for 100% E85 usage, did you change your req_fuel to adjust for the additional fuel required?

Employing a Dyno operator to tune your car is not necessary. Tunerstudio will auto-tune for fuel. You did buy tunerstudio didn't you?

No sensor and I was planning on 100% e85 usage! And yes I did change req fuel !