The stock intercoolers are very restrictive, i have herd 30 pounds of boost before the ic and only 20 out. They limit u to around the 500 hp range. The fuel rails u shouldnt have a problem with but i would suggest a split second ARC-2 w/ upgraded mas,and a fuel pump hot wire kit, maby a ken bell boost a pump if u plan on turning boost up.
Intercoolers will make a big difference, and inless ur planning on 800+hp i wouldnt worry about fuel rails.

 

Upgraded fuel pump with Hot Wire. The rest of the fuel system is fine for anything 15Gs are capable of.

Stock ICs will be fine if you are only boosting to 17psi. If you want to get the most out of 15gs by bumping the boost to 21-22 (w/ race gas), then you would probably want to consider DSM upgrades at a minimum.

I liked my ARC2, but there are cheaper alternatives out there now. 83mm MAS will be plenty for the 15Gs. I ran PTE 680s. Probably a little big, but my 550s were reporting over 100% IDC (found out later that that was not accurate). 550s would be fine for you.

You will love the 15Gs. I ran an 11.6x@121 with an unported/unclipped set and made 471AWHP on a mustang dyno. Great turbos.

Mark

 

I have 13Ts (comparable turbos). I am running my stock I/C and fuel rail. No problems here. Although, I do plan on upgrading my I/C so I can get a little more efficiency out of the turbos. I also believe the lower temps from the I/C will help supress knock some. If you have the money for the I/C then go for it, otherwise just put it off till u have the time/money.

 

You don't 'need' either... but I'd highly recommend getting some upgrade to the IC.

You can also just inject some form of heat quelcher or octane boost like water/alcohol just before the TB to help out as well.

But like i said... 17psi... you shouldn't 'NEED' either... you can always use stock ICs... but the boost pressure you see will have more HEAT than actual oxygen.
Stock IC's definitely aren't designed to run 300CFM+ from healthy bigger turbos for too long.

 

I'm in the middle of my 15g upgrade and I've got the DSM ICs already on the car (a worthwhile upgrade) but I'm sticking with the stock fuel rails. (going with 255 pump and 550 injectors)

From what I've read, upgrading the rail loop should be good enough.

 

Appreciate the responses.

It appears there is no performance difference between a 15g car that has upgraded IC and fuel rails and one that does not; this is particularly true if the car is used for normal daily driving and an occasional traffic lite or highway
race.

The sense I get is that the IC would be beneficial if you make repeated 1/4 mile runs or run the car at max boost for a sustained period of time, however, if you are just driving the car normally the stock IC can handle the 15g's.

Also, the stock fuel rails can handle the 15g's with no problem; that they will add virtually nothing to the performance of the car under normal driving conditions or an occassional race.

I guess a car would run better with an upgraded IC and fuel rails but in a race between 2 cars, one with the upgrades and one without, there would be zero difference and it would be a tie. On the 5th run, however, the upgraded IC car would win.

It seems that how you intend to use the car would determine if the upgrades are warrented. Daily driving, no...frequent racing, yes.

777

 

I guess a car would run better with an upgraded IC and fuel rails but in a race between 2 cars, one with the upgrades and one without, there would be zero difference and it would be a tie. On the 5th run, however, the upgraded IC car would win.

Depending on the boost you are using... 12psi coming from 15G's would probably already start taxing the stock IC a considerable amount. If you are running 15+psi(air intake temps grow exponentially worse depending on how high you want to crank the boost)... then ONE SOLID THIRD GEAR will be enough to heatsoak the stock ICs. So the upgraded IC will automatically have an advantage.

But even with all that said... the most important part of this equation is going to be tuning. You can tune with a restriction and still come out on top... but if the tuner is equally experienced... the upgraded IC will definitely pose an advantage.

 

Depending on the boost you are using... 12psi coming from 15G's would probably already start taxing the stock IC a considerable amount. If you are running 15+psi(air intake temps grow exponentially worse depending on how high you want to crank the boost)... then ONE SOLID THIRD GEAR will be enough to heatsoak the stock ICs. So the upgraded IC will automatically have an advantage.

But even with all that said... the most important part of this equation is going to be tuning. You can tune with a restriction and still come out on top... but if the tuner is equally experienced... the upgraded IC will definitely pose an advantage.

12psi from 15g's is cooler than 12psi from 9b's, so yes there is more mass flow through the IC's but they shouldn't heatsoak significantly faster that 12 or 15psi on 9b's
put the turbos on run then at the psi you want and see, if you need bigger ic's put em on (though i doubt they'll be necessary)
if you don't, put em on anyway

 

The reason I am asking these questions is not to determine if it is best to install
upgraded intercoolers/fuel rails or not, but if what they do is worth the money.

The cartech intercoolers, that were recommended by my shop, cost $1,700 plus installation cost. That's around $2000 for just the intercoolers. The horsepower/performance gains will be zero to very, very little. If I had unlimited resources this subject would not be worth discussing. I understand there are cheaper intercoolers available but I also understand the cartechs sidemount intercoolers are very, very good. I have found out in life that cheap is expensive.

I'll probably go with the upgraded intercoolers as I know it will make the car perform better, overall. It is just a heck of alot of money for virtually no appreciable benefit. Sometimes, having high standards is not a good thing.

777

 

You can get modified DSM's for like what, around $500? And a decent frontmount for 1k-1200. Screw your shop.

 

sean is right
stock ones are pretty good for 400hp*
DSM's will be good for approx 5-600 hp* (i had 300whp thru one on my eclipse but that was pushing it), and most front mount kits are 1-1.5k
your shop doesn't know our market

*there is no real max, but these seem like approximately what people do with them/about where they upgrade, i'm sure there are plenty of people out there pushing more thru them (so no need to post how you have 401hp on stockers etc )