Hey guys my evo 8 rpms fall really low like 200-300 rpm after I push the clutch in if I just accelerated with the car way past maybe 4k rpms, but it recovers. I'm glad I don't have it stalling everytime.

Is there anything I can do tuning wise to fix this? I have the tuning cable and have already messed around with many setting in the ECU just have not messed around the fuel map. Not even sure if messing with the map would help this. Or if there are any other settings I could change to fix this issue? Maybe setting for the idle control valve? I set my idle rpm at 1000 by adjusting the big screw on top of the TB.

I know I don't have a boost leaks nor a vacuum leaks, I already fixed the TB seals and tested the piping up to 35psi with a compressor. MAF Is also clean and car idles perfect.




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Do you have a wideband installed?

 

Lightweight flywheels can cause this hence, a lot of people use stock flywheels for better heat transfer and also to prevent what you are speaking off.

 

Yes I have a wideband bud


And my evo has a act flywheell, not sure if its lightweight (bought the car with it), with a twin plate clutch.

Also just remembered its set up to use a BOV not a recirculating valve, maybe this is my issue? Car was tuned by AMS I'm sure they took this into consideration.

But I'm not even into boost when this happens, I just accelerate up to say 3500rpms, no boost, push the couch in to say slow down or just coast and the rpms drop to almost stall and recover a second or so later. Add thing is that it doesn't happen everytime, maybe even 5th or 6th time. Other times rpms go down slowly and just stop at 1000rpm. Its almost like the idle control valve is slow to recover the rpms. Do these have issues with idle control valves? Perhaps its dirty, we on Hondas had issue with these all the time.



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Just as an FYI, most aftermarket flywheels will be "lighter" weight then stock. If your BOV is no recirc and you are running via the maf, please recirc and report back.

 

I was afraid of that. I have a very nice and expensive r2d2 BOV on the car. To recirculate it I would have to do some ghetto engineering. And my intake now doesn't even have a opening for a recirculation. I'll try to figure something out.



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Could always go speed density. Im running the same turbo as you and I would never consider going SD past 600hp. To me, it hurts driveability and isnt as consistent as a MAF setup. I would sell your BOV for some good $$ then go buy a recirc BOV.

 

I can make an Evo On SD drive 1000x better then a MAF is physically even capable possible.

Not to mention, The more airflow you produce the MAF is a bottleneck. Setups for example extracting 700WHP+ if you throw a MAF on there, they will drop 70-100WHP from being restricted so badly. Its a very big loss in power.

 

Yea I'm thinking I'm going to sell the BOV and buy an new intake and recirculating valve. Intake I have now like I mention doesn't have a hole for the recirc valve. Its just a custom intake from he MAF to turbo

What intake is everyone running with there recirc valve? I saw a few smooth silicone intakes on eBay, they look like they flow way better than the stock rippled intake.

I don't really want to go SD, I'm only pulling 400whp, don't really need more honestly as this is my daily.



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Some people think the stock rippled intake actually helps idle and driveability. I'm too lazy to put mine back on, but I had thought about it.

 

Went SD wish I could have done it 13 yrs ago. Drivability is insanely better than it ever was even 100% bone stock.

 

 

Yea stock intake is suppose to make the idle better and when the recirc valve opens but any other times is just huge restriction in your intake. If I had to guess it would problem be 25hp restriction on my 500hp car.

Plus my car is now tuned for a bigger smooth aluminum intake between turbo and MAF. Putting the stock intake back on would mess up the tune. I'm trying to fix my issue by changing as little as possible so I don't have to get another AMS tune.


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