JIMMYZZ28

Where did you get the intercooler? What size is it? Did you step down in plumbing size to connect to the intercooler? What is the before and after PSI?

ddnspider

iTrader: (26)

im with frcefed,got the OBX one yesterday and the pressure drop is rated to only .2 psi at 15#'s.check piping like they said and check the tune.

BOOSTAT4500

iTrader: (17)

I got the boost pressure back up, the by-pass valve needed to be adjusted despite what Vortech told me. The pressure is now back at what it was before, 10psi. We threw the car on a dyno and the first pull was down 45rwhp from before. However, it was way rich, so I turned the fuel pressure down a little as a temporary fix and the power came back and then some. My old best was 635 and it did 641 with tires spinning at 5500rpm. So I don't know what the actual power is now. I'm getting it re-tuned this week hopefully and I'll post results. As far people seeing a boost increase with a FMIC, I think it's from the aftermarket blow off valve they use ( that don't leak) vs. the ones that come with the ATI kit, and not the intercooler itself. The ATI BOV's leak really bad so they won't hold high pressure.

Blackbird

A few on here had aftermarket bypasses already and then saw the increase in boost when switching IC's.

JIMMYZZ28

The intercooler can have a generic rating but the compressor efficiency is what delegates the rating in the intercooler. So what may be good for some may not be good for everyone. It could go either way to big or to small of an intercooler could hinder performance.

TeeKay

Hey, I'm glad you found and fixed the problem. It's always something, ain't it?

But here's some basics. I've got some IC background and I'll tell you for sure the IC is an additional restriction that, if you don't do anything else but add it, will use up about 1-2 psi. Just for S&G, imagine a 10' long pipe from the blower output to the TB. Now take out about 2' in the middle and add a double S-shaped 6' piece of slightly smaller diameter. What do you think the boost will do?

Here's the deal, the psi at the blower outlet will stay exactly the same (the wastegate setting - unless it's referenced to MAP), but the psi at the TB will drop. If the charge is cooled on top of that, there's less volume (and psi) at the TB than at the blower outlet because of the temp drop. The charge has got the same amount of oxygen molecules, just in a smaller space. The "goodness" of the IC comes with running the same or higher (!) boost at the TB (adjust the wastegate setting) on a cooler charge with less or 0 knock. In my experience, if you add intercooling, the boost drops and you add timing and you gain power. If knock will let you, add timing AND increase boost readings to what they were before and you gain even more power! Boost is not HP! Boost is one of about 3 basic ways to add HP, timing's another for instance, proper AFR is another. They all have to work together. This all assumes almost no knock!

I hope that makes sense, it's true.

Slowhawk

iTrader: (12)

When your on the dyno throw away the inlet hat for 1 run.We gained 4lbs of boost and gained 100hp on a car recently Now we are working on a custom inlet hat

SSprayn

Gez I hate reading something like this. I have been looking for a while now at taking off my vortech aftercooler and putting on a FMIC since I drive the car on the street alot. Let me know how everything turns out before I go spending all this money!

JIMMYZZ28

Yeah its like sitting around talking about cams. Let me know if you are interested in one and we can size it right for you. Just make sure you have all the information from your compressor and envelope size you have to work with when you call. Remember when sizing the unit that the larger the core face area is the thinner the core can be thus more efficient (less residual heat). If anyone is interested we have a limited supply of units that are listed on ebay here is the link. http://cgi.ebay.com/ebaymotors/ws/eB...tem=7969481874

ktmrider

Yep, a more efficient IC will cause a drop in pressure at the TB due to the denser/cooler air. The IC does induce some drop too due to restriction. Some of the STS guys saw similar issues when installing the IC until they changed the wastegate tap location downwind of the IC so it saw the "reduced" pressure.
Ever notice how your tire pressure is lower when the outside temp drops? Same idea. The air did not escape, it just got denser. This is why you should always check your tire pressure with the tire cold as it could give you an incorrect reading.

F8L Z71

Jesus is anything good on the ATI kit besides the head unit? It seems like everyone loves these kits but throws everyhting away except the head and replaces the parts with afteremarket or custom stuff. LOL

Go ATI! Hahaha

MelloYellow

Didn't read entire thread.
Did you re-tune after the change?
Your A/F may be off, losing power.