Jump to content
HybridZ

GN Intercooler


Bernardd

Recommended Posts

I'm not sure it's much better. At least a stock one is reputed to have a restrictive outlet, and the popular upgrade is to have a larger one welded up. If I'm not mistaken it's a tube and fin type, supposedly more restrictive than the bar-and-plate style from Spearco.

Link to comment
Share on other sites

Guest bastaad525

I bought one used for cheap from Tim240z... I am not knowledgeable enough yet to look at it and go "hmmm this is a good I/C" but a couple of friends of mine who run turbo cars saw it and were pretty impressed... especially considering I only picked it up for $50 :) It looks to be a pretty heavy duty unit... it's very THICK, but height and length are definately short enough to fit in front of the radiator pretty easily. As Sleeper said the one thing I can see 'wrong' with the thing are the inlet and outlet necks, they look a little restrictive and are very oddly shaped/placed for use in a Z... I'm going to have them cut off and weld on shorter ones that will point off to the sides for easier, less restrictive routing. Otherwise I think it will work out perfectly... it's designed for a bigger engine that runs more boost than the L28ET, and I've read of guys running 400+hp Grand Nationals that still use this stock factory intercooler, so it's gotta be good enough for my 200+hp Z :)

Link to comment
Share on other sites

I'm not sure it's much better.

Beg to differ. I always look at OEM I/Cs based on the rated engine HP, which equates to flow. The GN engine was factory (under)rated at 247hp so as not to embaress the Corvette. Many GNs running 350+ with it unmodified and in a GN it is mounted between the radiator and the engine and "covered" with a shroud that draws fresh air below the radiator. Can you say "heat soak"? In a Z I would cut off the neck and weld on the appropriate elbows for how you plan to route your plumbing. Starions, Volvos, Saabs, etc had factory rated engines from 160-180hp. Do you think those OEM I/Cs were designed to have extra flow capacity to support 275-300+hp w/o pressure drop?

Link to comment
Share on other sites

I guess I just know a local turbo Buick guy who complains about the IC. He's got a Duttweiler neck upgrade, but he's also got the capability to run 600rwhp as soon as he can figure out how to tune the thing without blowing his tranny out (again).

 

My statement disparaging the GN IC is just based in lack of confidence of OEM intercoolers in general. My Spearco is quite small, 2" inlet and outlet, but is capable of 625 cfm and running 11s in a Z, so I tend to compare from that point of reference.

Link to comment
Share on other sites

Guest bastaad525

Again I'm no expert here, but to actually have the thing in hand and look at it, it definately looks like flow would NOT be a problem with this I/C... whereas I've seen the Starion ones and you could tell the thing would not perform so well. If there's any restriction in the GNX IC its in those necks, which as I and scottie both said, would be better to have them cut and put some better ones on there... even for $100 I think this is a really good deal for what I'm sure would be a great performing unit

Link to comment
Share on other sites

Retriction before the IC could be a good thing. I mean, slower you can transfer the air through the IC, more it has time to cool 8)

 

:roll: Did you borrow that line from the radiator cooling people who caution against pulling the thermostat? ;)

 

Again, all a restriction is going to do for you is create a pressure drop resulting in more heat in your intake charge.

Link to comment
Share on other sites

Guest bastaad525

*shrug* could be... he was going to use it on his ZXT but sold the car so let me have it for a song and dance... I still feel it is the second best deal I've gotten on parts for this turbo so far, after the $10 DIY boost controller :) ($10 got me what... 30-45 extra hp? SWEET!! can't do that with an N/A motor!). I'm actually thinking not only of cutting the necks off, but welding two block plates over those openings, and installing new inlet and outlet necks coming straight out of the sides of the end tanks. Just seems more functional to me to have them straight thru like that. I'll definately let you guys know how it goes... *sigh* I just wish it would go FASTER. Still looking at like a month, at least, before I can get it installed...

Link to comment
Share on other sites

Guest bastaad525

that's overkill man... I really think one will do the job... remember there are guys running 600+hp GN's with the stock intercooler still... dont believe me? go to some GN fan pages or forums... Oh and I think pressure drop accross one GN I/C was something like 1 or 1.5psi at stockish hp and boost levels.

Link to comment
Share on other sites

that's overkill man... I really think one will do the job... remember there are guys running 600+hp GN's with the stock intercooler still... dont believe me? go to some GN fan pages or forums... Oh and I think pressure drop accross one GN I/C was something like 1 or 1.5psi at stockish hp and boost levels.

 

If that intercooler is dropping 1-1.5 psi at the stock hp level of 300hp (I know, I'm generous) that means at 600+ hp, that unit is dropping 4 to 6 psi. That is not good. I think 2 in parallel would work well - it's a popular GN IC upgrade to extend the endtanks lower to the ground - not sure they get more than 4-6 inches, but every little bit helps.

Link to comment
Share on other sites

Guest bastaad525

I could be wrong about that number, was a long time ago that I read that. I know the pressure drop was minimal, especially compared to the 3psi or so that the starions lose.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...