Built 13b hard cough under boost. Video
 

Here is the problem


I have another thread but feel this section may be much more suitable, here is a link to the original thread if you feel you have a solution someone else hasnt already offered. Im not shrugging off anyones suggestions im just looking at ALL the info presented to me before i go spending money.

https://www.rx7club.com/rx-7-audio-v.../#post11359336

Thanks everyone for all the support!

Throw in some fresh plugs or verify the ones you have are in good condition if you haven't done so yet, and if you can try to borrow a twin power. How much boost are you running? Does it run smooth if you go lighter on the throttle?

sounds like boost cut in your EMS.

some electronic boost controllers will give a similar symptom if you reach the boost threshold and have a large step in the warning % set. Greddy Bspec2 comes to mind and have something rediculous set like 25%+ in the warning setting. it will basically clap your wastegate wide open and dump all boost if set too high.

basically you are overshooting your target boost level settings, either due to the wastegate hooked up improperly or your boost settings set too high, or boost cut level set too low and you have surpassed it.

more info on your setup would be very helpful.

It doesnt happen everytime, mostly at wot though. Before it was happening higher in the powerband, say around 7k. Now its a bit more sperradic but settles right around 4500 for the most part. Feathering it helps.

Possible in a limp mode (?) since im test driving it without some sensors (oil press, water level sensor) My commander is at 7800 cut. No EBC for setting gain/boost or anything.

I will do the plugs and get everything hooked in nicely to avoid spending money i dont have to.

Mods are all in sig except; 340lph aero pump, Kg fuel rail, fuel lab fpr@40 idle, full 3' exhaust with a twinscroll mani and divided turbo on a .84 hotside.

Earlier that week, the problem happened much less but got progressively worse.
The broken power band makes me cry :(

Fd rx7 hard pull - YouTube

i wouldn't be flooring it like that lol it sounds like leaning out and hitting fuel or boost cut for sure.

Do you have a wideband? Is it leaning out or going full rich? who tuned it?

boost is not always going to be set at a steady number, there are a number of things that affect boost levels like ambient outdoor conditions and ambient underhood conditions.

look up the things i mentioned or send the car to a tuner shop for diagnosis.

I've had quite a few cars with quite a few turbos for each one so I understand how boost fluctuates. Ill look at the commander to see if it is set at a specific cut though, thanks for the advice.

It's running off a power fc commander. No wide band yet

do you have a wideband a/f gauge?

default setting will hit cut at about 14psi. so how much boost are you running?

It's getting to 8-10psi. I didnt find a boost setting on the power fc commander, no afr yet

i forget the table it is under but the setting is in Kg versus psi and default is .75/.85 iirc.

I only saw a boost option to change a percent and their are 4 for sec and pri, you can text me if you think your onto the answer and itd be easier for you. 8134825048

This may not be your problem but I had one cell in my fuel map with an incorrect value. whenever that cell was hit it sounded exactly like that.

Did I miss where you posted the afr at that blip?


nvm I saw the "no wideband".
I personally would not be pushing a car into positive manifold pressure without an AFR readout.

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Here is the commander info, let me know if anything weird is set, thanks.