Big H1C (hx35) Spools to fast causing surge?! help!

[volkri25]

Had my car tuned today. Runs great minus 1 thing. Im building to much boost to fast with my car causing a pretty severe compressor surge at a low rpm range.

Im getting 30psi by 4k rpm with my H1C and it seems my car cant flow enough at 4k for it. Its really bad in 3-5 gear, and is obviously unoticable and short lived in 1st and 2nd. Now If I do pulls through the gears, and shift into the next gear while boosting around 5k rpm the surge doesnt hit. Its only from 3.5k to 5k and at around 7psi to 15psi. Never surges after im past 15psi. I know this isnt as bad as having a stuck wastegate with a full load of boost but the car performs slow in a cruising state of driving.

Mod list:
9.0:1 wiseco pistons
eagle h-beam rods
6 bolt block

bc 272 cams
bc retainers and valvers
fidanza adjustables
7 bolt head

evoIII intake manifold
1g 60mm throttle body
vrsf intercooler

fp exhaust manifold
H1C on a .55ar bep housing
punishment racing 2.5" o2 housing
tial 38mm external wastegate w/ 17psi springs
tial 50mm q bov
megan racing dp
tsudo n1 exhaust


Basically I am looking for the most reliable solution. Got the car tuned today, however cams where not adjusted, not sure if this would alleviate the surge. I have a 10psi spring in my q which is 2 psi too strong for my vaccuum level, however the surge happens in boost, which means BOV couldnt be the culprit.

I feel helpless on what to do. The 9.0:1 pistons are helping it spool just way to fast, same with the evo3 intake. I feel like switching to a t3 .70 ar system would lesson the backpressure enough.

Opinions and help would be GREATLY appreciated!

-Kyle

 

[Ceddy]

Enable boost control.

If you can do boost by gear, just lower boost at lower rpm and affected gears.
(Where you are having surge.)

I feel helpless on what to do. The 9.0:1 pistons are helping it spool just way to fast, same with the evo3 intake. I feel like switching to a t3 .70 ar system would lesson the backpressure enough.

Compressor surge is caused by the turbo spinning up to fast and crossing its surge line, not by back pressure. Although a larger hotside will slow down spool up and help.

 

[volkri25]

Cant do boost control, dont have an electronic boost controler, or even the stock one on. Ill see what I can do though. Great idea. And yea im going to attempt some other solutions first. Getting a softer spring for my Tial BOV, as mines too stiff. Im currently running my MBC and BOV on the same vac line which will be fixed, and ill be running the correct vac line sizes, not a size to small like i was. Im also going to play around with my cam adjustables to see if I can eliminate some of it. Hopefully all these little things with nearly exstinguish surge.

 

[turboglenn]

Trade me for my t3/t4 hybrid Nd let me deal with th surging problem I'm making 438hp at 29 psi on e85

 

[volkri25]

hahaha im making 380 at 28 psi on 92 octane. So you got me beat. However Im starting to think my BC cams which advanced because there ground off a little, giving me just enough bottom end increase to cause my surge. That and I have some BOV issues. Im shooting for 400. By hybrid you mean HX40/35?

 

[spoolin ddub]

hahaha im making 380 at 28 psi on 92 octane. So you got me beat.

If you are making 380whp at 28psi I can't see that turbo flowing enough to be surging. What rpm does it hit 7psi and how much hp is it making at that rpm?

 

[Twistaye]

Hm..... Honestly I was having the same issues you're describing on my IX with my stock turbo. I couldn't get on it in 3rd, 4th or 5th without the car surging. All it took to get my issues fixed was a tune. I know you just said you got tuned but I know the tune fixed it for me.. I can put it in 5th gear at 20 mph now and just stomp my foot to the floor, no more surging issues.. Just a thought of course. Hope you get it figured out.

 

[19BLACKGST98]

However Im starting to think my BC cams which advanced because there ground off a little, giving me just enough bottom end increase to cause my surge.

Do you mean your cam lobs are worn or what? Just seeing what you mean by "ground off a little"?

 

[JusMX141]

I assume he means that the lobes were not aligned perfectly to the placement of the cam gear dowel....hence being "off a little".

As time progresses we're finding that Brian Crower cams are among a few brands that more than likely will need to be degreed upon installation. Some guys install them straight up and have great results, others need as much as 4* or more of correction to bring everything into alignment.

 

[volkri25]

and because of that, that 4* or whatever degrees its off could be causing me to gain a few hundred rpm in spool, causing this surge. He is an amazing tuner (the person that tuned my car) but he didnt have time to tune the cams in. So its GREATLY possible that there off in degree. Not to mention I bought them from a member on here (new) but maybe he knew they were off, idk.

If you are making 380whp at 28psi I can't see that turbo flowing enough to be surging. What rpm does it hit 7psi and how much hp is it making at that rpm?

Im making 7psi by 3250 rpm and 28 by 4k.

 

[forcefed86]

Sounds totally bogus to me. Unless your off a tooth, it is very unlikely the cam is to blame. 10:1 it's in your tune.

Decrease the overlap in your cams a few degrees and give it a shot. I have no surge issues. Running a smaller housing and turbo on a very similar setup.

 

[volkri25]

Got the corrent 8psi spring in my Tial Q bov and all surge between shifting gears and on decel is gone. However I still have surge from 10-15psi in 2nd-5th gear when wot below 3k rpm. Its not a bad surge, but its still there. Even at part throttle in low rpm it surges. Whenever im above 4500 rpm and wot 0-28 psi with no hickups. Could it be the tune, maybe. But It was tuned by a very reputable shop. Im going to see if my cams are the issue and do -3 exhaust +1 intake to increase overlap, and hopefully flow colder gases at low rpm

Also noted though is from 1200-2000 rpm the car bogs a little bit and dosent want to go. Maybe It because i moved my AEM 3.5 bar map sensor onto the same lines as my fpr and boost controller but im not sure.

The car may need a fine tuning. I mean im pulling 28psi with less then 1.2 degrees knock so it is tuned to wot.

 

[a1320eclipse]

I would say thats in the tune. Do you have a wideband in the car? What are the AFR's when its surging. Its sounds like an overly lean or rich condition down low, which in the past ive personly seen high end reputable shops not get right. Ive seen a lot of cars tuned 100% on the dyno that dont really drive that well and have issues in boost at lower RPM's cause dynos cant always fully replicate the street. ###### nothing a touch up in the tune cant fix.

 

[volkri25]

Ive attached some logs. A few things catch my eye. Airflowperrev at idle is .40 when it should be .25 on a 2.0l. Not sure how this affects anything however.

When surge happens in my run log. My A/F goes to about 11.2 pretty quick which seems right. Timming is around 5-6 degrees. LTFT Lo and Mid are both around -10.

And the highest knockret I ever get is .04 on two occasions, so I have some room to play with I believe.

Input por favor!