I have a question..

Just received my UPS notification -- my FI exhaust will be here on Tuesday :happydance:

got my notification on my 18'' cbe,cant wait:driving::driving:

Exhaust and HFCs will be delivered tomorrow!!! :leghump:

Hey Tony or whoever,

Two questions, one has been answered a few times on this thread before but I cant find it, what is the "hissing" noise that i get when i am off the gas pedal? does it have to do with backpressure of some sort? just curious. Next question, having the HFC's and Exhaust, has anyone noticed an increase in oil temps? just curious because yesterday i was cruising around, not even really romping on it, and the oil temp was at about 240 steady in 80 degree weather... thats higher than normal from what ive seen with the car...

Hey Pelican,
While I don't have HFCs, my understanding is that the hiss is inevitable. I'll let someone more technically savvy explain it better.

In terms of the oil temp, I've been in the 220 range before. Limp mode kicks in at around 280 I think? I don't think 240 is anything to be concerned about, but again I'm not up on the details of the oil temp thing.

yea, the hiss isnt a problem, i actually think its kinda cool lol, just wondering what it is exactly. And the oil temps I was just curious about because i havent seen them that high until i put the bolt ons on... Thanks for the help though...

I've never fully understood the technical reason for the hiss, but all our cars seem to have it HFCs at least. It happens on decel at a certain RPM range. Personally I kind of like the sound, but I'm wondering if it will change or go away with LTHs. I'll find out soon :)

Re: oil temps, keep in mind the ambient temp is warming up everywhere as we enter summer, and this has a huge impact on your oil temps, it's likely the reason you're seeing a rise. I'd say as long as you're not regularly staying up past 240 (e.g. 260+) you don't really have anything to worry about. A good oil cooler is the solution if you're tracking the car, or driving it hard in hot climate. The exhaust setup isn't really going to change the oil temps situation much, except that maybe you're more prone to pushing the car harder now that you enjoy the exhaust note more.

I understand the fact that its getting warmer out, but last year even in the hot humid summer, it never got past 220 and now when i was driving mildly on the highway, it was sitting at 240... thats strange and never happened until i got the bolt on's on...

What other bolt ons do you have besides CBE and HFCs? It could be you're running a bit lean.

thats it besides the HPS tubes and AFE dry flow filters... I dont see them causing it to lean out. Im just going to keep an eye on it. If it starts hitting the 260 mark, ill probably spring for the oil cooler...

First point - The hiss comes from having an X-Pipe. Has nothing to do with Stock cats or HFCs or test pipes. If I recall correctly it is from the equalization of backpressure between the two sides of the system... Tony will have to come in and 100% answer that one. But the only way to defeat the hiss is to have either a complete dual system or have an H pipe as with the Nismo exhaust.

Second Point - The overheating issue... When you installed your CBE/HFCs, did YOU do it or did you take it to a shop and have them do it? In either instance, did you get it tuned afterwards? If no tune did you at least pull off the negative battery terminal for a few minutes to reset your ECU? Adding these breathing mods allows your engine to flow more air = more power. However comma if you haven't reset your ECU to adapt to this, it might still be running the same cooling maps as it would for stock. Which now that you're getting more power your block is heating up faster and the ECU isn't compensating for this. If you haven't done the battery reset, I would suggest to try that, remove the NEGATIVE terminal for about 5 minutes. Then return it and crank. Let it sit and idle for about 10-15 minutes. Then take it around the block a few times without getting on it. And let your ECU learn how your engine reacts with the new mods. Maybe this will help it adapt better and keeps your temps back down where they were. Or it could just be due to the weather getting warmer/more humid...

LTH's will not effect the sound at all. It's still there loud and proud. :tup:

Are there any other advantages of having a true dual exhaust over something like the FI? Does it make more power?

I don't believe there have been back to back dyno's to show whether or not it does. For an N/A car it's a bit excessive to have a full dual. If you are F.I. then I think it does benefit if you have a TT setup to run true dual 3" tubes...

Thanks :tup: