Yes, my cam pullys are adjustable, but are currently set to 0,0.

As for AFR....13 at tip in, then to mid 12s. I am still having a bit of an AFR issues that won't allow me to get the AFR any richer than 12.3-4.

Ideally I would like to have 12.5 at tip in. Then 11.8 to redline.

 

I have an APS dual vent that is recirculated and quite tight on the adjustment. I have a single vacuum line running from it to the intake manifold on the large nipple that faces forward and is toward the inlet of the intake manifold.

The BOV has been re-built/lubed and tested. It does lose it's vacuum over time. I believe the primary piston seal is worn slightly.

 

Hi,

I have adjusted the pulleys before to try and make the car spool later on and this did get rid of some of the surge from the turbo, I take it you are on the stock ecu ?

Can you not change the lean spool afr table so it runs richer on spool or fit a FRP or is it a fuel supply issue ?

Lee

 

Well my loose vaccum hose was not the issue, I still have the surge. Do you guys think that a retune will fix this?

 

I replaced the spark plugs.....no dice
I tuned the spool leaner.... no dice
I double checked, tightened, zip tied every vacuum line....no dice

It appears that there is something electrical going on. My next step is to remove the HKS DLI II from the ignition system and test again. Then I will try the MAF.

In the log I get a huge load drop at the point of the "surge". AFR goes rich at this point too.

 

Try decreasing the gap a little on the plugs

 

Gap on the plugs is .020. Can't go much smaller.

I am not getting spark blow out at high rpm. I don't believe the plugs are the issue.

 

What kind of spark plugs are you using?

 

Was on NGK BR8EIX....switched to BR7ES

Same result with both plugs. Both were new when installed. Both gap was .020.

 

Bigger cams that slow down spool would help, but the simplest, best and most expensive solution is a 2.3 shortblock. I tried all the tuning stuff and eventually gave up and went 2.3 with my gt3076r and now make 200whp at 3000 rpms with the stroker motor with no surge except with a highway pull in 5th.

 

Sweet!!!!!

 

I have HUGE lift cams. The problem lies in the fast spooling smallish turbo and the tons of porting I've done. By correctly adjusting timing, fuel, and EBC settings I am able to control the surge.

What I am experiencing is a bit different. It is as if the car hits a brick wall when coming onto boost at about 18psi below 3500 rpm. It is as if the ignition completly cuts out for a brief moment, then the car pulls like hell. There is a cut in load and a moment of rich afr, then everything is normal.

I thought a re-flash with a fresh rom would solve the issue....nope. It is still present. I just learned to drive around the condition by not trying to boost too low by downshifting if I feel the desire to get on it.

 

Your right, that does sound like more of a tuning issue-when my turbo surged the car shuddered vilolently as the air backed up to the turbo.

 

Hi, can anyone post a VDR graph showing this type of problem? I was having something similar with my car (Evo5 RS ported stock turbo) when hittings 26 to 28 psi on 4th gear pulls. The car would not shake or make strange noises, it would just go nowhere until it hit like 4500 rpm and then it would realy push.

I have since changed the hotside from the original dual flapper Evo 5 to a more modern single flapper hotside, which I also ported. But now since I also cleaned up (slightly ported) the waste gate channels of the single flapper hotside I think this hotside is too efficient and can no longer boost past 22 psi, even with the Hallman MBC turned all the way closed. Anyway I´m still debuging my setup cause there may be a pre turbo exhaust leak that is also not helping in building boost.

Cheers,

Ricardo

 

Appauldd I just had this issue when I was trying to use a 36A mac valve (that I got with my HFS-6 kit) for ecu based boost control. First the stock solenoid was starting to surge in 4th and 5th, so I put in the 36A mac valve and everything went to hell. I would build 27lbs by 33-3400 and it would just surge like mad. It would buck really bad too, it wouldn't do it part throttle but when I went to do a pull it would. I tried for about a week with that valve and got fed up with it and bought a Grimmspeed BCS. I installed it and left it unplugged to make sure it wasn't a wastegate issue, it wasn't and then I plugged it in and it held 18 lbs no problem with no surge and now I am just tuning it to get the boost that I want.

Just a story of what happened to me and it could be that your Avc-r solenoid went bad. It happened to me on my old electronic boost control setup on my old Rx7.