From what I understand you don't need an anti surge housing until you bump up to a large-displacement engine. I don't know, other than that. I keep things on my car OEM looking and super simple, so I've never really looked into them.

 

Yea I was up until about 2 am researching BOV and DV had it down to a synapse DV and then Drew at Map said stock is fine. Lol But it did save me a few hundred. Ordered the EF3 with all the options except anti surge. Now ten long wait until it comes in.

 

My experience with the stock DV is somewhat different. It would hold 25 psi no problem during a boost leak test, but when I was running 25-27 psi peak boost, no matter what I did to my tune, I couldn't stop AFRs from going rich during spool. I eventually installed an aftermarket DV, and the rich dip disappeared. I can't explain why it mattered, but it was the only change that I made at the time.

 

The stockers are designed to leak so people don't make so much boost. (sorta)

I agree with Mr Fred though, I have had lots of boost leak issues on a stock non modified DV. I crushed my stock one back in the day which helped a lot but since have gotten a proper aftermarket one that doesn't leak.

 

Weird. I have a crushed, OEM diverter and have no issues. The tune is spot on. This is at 25psi on an ef2.5. I admit I have not tried any more boost, though, as I am on 91oct.

 

2.4/EF4 on a dynojet

today I made 420/415 on 91 pump @ 30ish lbs. in 100 degree weather.. it was running super rich so still need to do some more tuning ill be back with more updates...

 

I have a question for anyone with experience with the EF 2.5 turbo. A ring land in my motor broke a couple months back, and I shipped the car off to KevinD for repairs. Ended up doing an EVOD stage 1 rebuild good for 600whp. I had them pull the turbo, and apparently the previous owner had been running the car with no air filter, or chewing on the rotor. The car was modded before the ring land went, but it never made the power it should have, or spooled the way it should have, and now I know why.

Anyway, I decided to upgrade the turbo to the EF 2.5. My question is what kind of power should I be expecting with the new setup? Mods listed below:

Megan O2 housing
Megan 3" DP
HKS carbon Ti catback
Ported stock turbo manifold
Mil.spec 3" 100 cell cat
ETS intake
ETS upper and lower IC piping
ETC 3" wide tank EVO IX intercooler
Walbro 255
Sparktech COP
FIC 780 injectors
Grimspeed 3 port
Forge WGA
Stock IX BOV
And the motor is fully built as I said earlier.

The car also has a TRE 6 speed, Fortune Auto 500 coilovers 10k/12k setup/corner balanced by Kevin.

 

The injectors look to be your limiting factor. On 93, I'd say 420 on a dynojet is not out of reach.

 

That's it? I was figuring a bit more than that. I did think about the injectors, but I didn't think they'd be that much of a hindrance.

 

I haven't checked IDC's with my 780cc injectors, however I'm pretty confident you can go higher than 420 DJ on those injectors ODUB.

 

my rule of thumb for estimated horsepower is your injector cc/2. I make it a bit less for safety. for example, I am at 390whp on 1050s but limited to crappy 91oct. I have more injector left and can check the IDC, if you're curious.

Using that math, 780/2 = 390whp safely. If you're gas is better than CA 91, then you should make a bit more.

 

^^^Difference probably due to temperature of the bov especially the spring when test is conducted vs. when the bov is exposed to the heat from the engine. I would imagine if you did a boost leak test with the stock bov and put a heat gun to it you would be able to make it "leak"at a lower psi than than 25 psi.

 

It should seal better when there's heat on it. Everything expands, and clearances get smaller, and tighter.

 

I suppose there could be some temperature affect, but a quick Google search reveals that Young's modulus for spring steels (and most other steels) does not vary appreciably between room temperature and 150F - maybe 2%. So its not a huge effect. I think its more that the DV was at its limit.

The interesting aspect to contemplate is how would it even cause a rich dip. Since the DV recirculates, the air should already be accounted for, and there should be no change in AFR with a leaking DV.

 

Well....IM is still seeing less air than the MAF, so kinda makes sense.