|05-14-2004 10:46 AM|
|Boxerchip||ive got an abbott racing one in my viggen. it seems nice... but it sits too high so you cant see it and its not getting air that well. is there a way to lower it and move it foward a bit?|
|05-14-2004 05:50 AM|
|TK900SE||i think it looks good i dont mind at all being able to see the ends of the intercooler id take that set up anyday not only that but his is actually down in the opening able to get good airflow most ive seen are up behind the bumper and do not get such a direct flow to it|
|05-07-2004 12:00 PM|
|04-27-2004 05:33 PM|
|mike saunders||Thanks, Tweek. I thought your 600 EU comment referred to the other one, but I guess you're looking instead at paying $250 for a tube-and-fin IC with basically stock dimensions....|
|04-27-2004 04:10 PM|
|Tweek's Turbos||If you read the Saab Central post from up above, his cost was only $250. I pmed him for some more info.|
|04-27-2004 02:08 PM|
Yikes! Tweek, with the brutal exchange rates, 600 euros is $712....that's two Spearco ICs, each capable of 400hp....Can I have one?
Eric, thanks for clearing that up...To sum up: effecient endtank design that minimizes turbulence will minimize pressure loss across the IC....
|04-27-2004 11:31 AM|
Good thread. I am going to yahoo money exchange EU600.
What about cutting out the space in the bumper, and welding in roods for strengh. It should allow some better flow to higher sections.
|04-27-2004 09:50 AM|
Thatís a good article, Iíve done similar work in my Gas Dynamics class. Iíve studied laminate and turbulent flows through heat exchangers, but the flow calculations in the diffuser are graduate level so I havenít done them. You are correct in your statement about the importance of end take design. In my last thread I was pointing out that the inlet/outlet location did not effect the flow distribution through all the fins. The flow will be evenly distributed through all fins regardless of inlet/outlet location. However, poor design of the inlet/outlet on the end tanks will cause excessive turbulence, resulting in a larger pressure drop.
Lets assume that the two intercoolers pictured below have the exact same core. So the only difference is the inlet/outlet location. Both intercooler will have evenly distribute flow through the fins, but the second one, with the inlet/outlet at the bottom will have a larger pressure drop across the intercooler due to more turbulence in the end tanks.
The main causes or turbo lag are compressor/turbine rotational mass and exhaust gas velocity Ė and the time it takes to increase. A restrictive intercooler will cause more backpressure on the compressor to achieve the same boost pressures. So it can add to turbo lag. However there are several other factors the must be present before a bad intercooler becomes a significant source of turbo lag. These include high required boost pressures, air volumes and the turbo compressor map. I donít want to get into this anymore though, and donít fell I have a good enough understanding of it to make further statements on the subject.
To get back on topic the main problem here is finding an intercooler the fits the hole of the Viggen bumper and fixing the oil cooler hose problem. I think the solution will be an intercooler the looks similar to the EVO front mount intercooler.
|04-27-2004 08:01 AM|
Hi Eric, thanks for your input! Definitely glad you're in on this....
I was told by several folks that there were definite pressure differences within the intercooler and that the job of good end tank design was to minimize them by increasing flow. I think my analogy about the pressure gradient likely overstated the level of pressure difference -- especially since there's a constant volume of air in the system -- but check this out:
http://www.netl.doe.gov/publications...df/ATSP-18.PDF. This shows a direct relationship between pressure and flow in a linear turbine intercooler, with the aim of equalizing the pressure and maximizing velocity....
Would the ease of flow have a direct relationship with the pressure through the system? Also, if the constant volume of the system is factored out, doesn't the entry and exit pressure difference, possibly heightened by poor design, contribute to lag?
If my head wasn't already shaved, I'd complain that these questions were making me pull my hair out!
Snow, I think the massive GReddy unit uses the bigger is better philosophy and kills the angled tanks in favor of adding more tubes....
|04-26-2004 11:08 PM|
|04-26-2004 10:56 PM|
This is a good thread and has brought together a lot of helpful intercooler pics. I started up a page of intercooler options to bring everything together here.
My favorite design is the one pictured below, the one I put on my Saab will be a similar design. The intercooler has to be lower than the Viggen intercooler so that it gets better airflow and therefore cooling and so it fills the entire whole in the Viggen bumper.
Iím not going to move the oil cooler however. Instead I will either bend or refabricate the lower hose or I will simple angle the intercooler so that it clears it. Below is the look that I am going for. Ignore the car, but the intercooler fit is perfect.
|04-26-2004 10:38 PM|
Hey, awesome post guys, itís nice to see getting so much help on this. I'm looking at the different designs and I see what your saying Mike. I looked up that EVO 8 IC, looks nice I like it a lot but your right it does need some modding to make the pipes fit. While looking I came across this site. http://www.roadraceengineering.com/e...ntercooler.htm
If I get this right too much space on the top is wasted so it needs to be evened out. If thatís the case then why would GReddy make an aftermarket IC like that for the EVO? The tubes are placed lower on the aftermarket IC then on the OEM. Is this a bad thing? Iím still a little stumped as to what design is the best, you said the EVO but then why is the aftermarket supposed to be better with the tubes lower? Please correct anything if Iím wrong just trying to learn more about it.
|04-26-2004 10:10 PM|
Ahhhh.....thanks Maarten!...those custom tall and narrow ones are what I was talking about when I mentioned ones with much of the IC hidden behind the mass of the bumper. The other design flaw is that the bottom 1/3 of the IC, where the inflow and exit tubes are, will be doing most of the work, while the top 2/3 is mostly wasted.
Here's why: the air entering the IC will try to take the most direct route to the exit -- the first 6-7 inches from the bottom. The air will try to ram its way through here (and get sucked out the other end) until the pressure forced it to move elsewhere. The only place for it to go would be higher up the IC to another series of tubes. There will be a definite pressure gradient from high to low as you go from top to bottom, with the top not doing much work at all for most of the time...
A better design would make the bottom of the end tanks significantly larger and make the tanks taper severely as they went up the core to even out the pressure and make more of the IC pull its weight in cooling. (Look at the Saab 9000 IC; flows poorly but is designed correctly.)
Or....have equal sized endtanks, but an exit at the top and entry at the bottom of the opposite end.....Another design might also be closer to the Mitsu Evo 8, with angled tubes and different volume endcap sections to equalize the pressure in all the tubes.
I know...I'm obsessing over this whole intercooler thing. I spent something like 40 minutes on the phone with an engineer from Bell Intercoolers last month. I think his name was Gunther, and he was incredibly helpful...He confirmed that the top and bottom tank/vertical core design (look at Procharger) offers maximum cooling with the least pressure loss....but it won't fit easily in the nose of a Saab!
|04-26-2004 08:24 PM|
Re: Custom Intercooler
If you want to buy an intercooler that looks good when you've fitted a bodykit, the next one may not be what you're looking for. If you're looking for better response and more power, it might be an option. The Finnish Saab Club did a groupbuy for these intercoolers. They're good for powerlevels upto 400hp and you can keep your airco. Price is 600 Euro, shipping not included.
On the STCS forum there's a guy who makes intercoolers for the 900/9-3. He posts as 'Magnus2074'. The intercoolers look alot like the ones from Maptun you've been looking at, which I think are made by Kylar Jonson in Sweden.
I have no further information about Magnus' intercoolers, but here are some pictures.
|04-26-2004 08:11 PM|
I was just looking at Bell and Spearco. 8" tall would be good and Iím sure I can fix those pipes, but I think 10" would we perfect. How deep can I go with that? Prob no more then 3 1\2" if that? I know 10" height is kind of pushing it but I know it will look so nice. I'm a little worried about fitting the think, but then I looked around and every site out there has so many fitment pips for it. So Iím sure that wonít be a prob. I just want to get all the specs and the right company so when I do order in the future I will already have all the info.
|04-26-2004 07:50 PM|
Snow, you could probably fit one that was 8'' if you bent the oil-cooler tube verrrrry slightly. Problem at that point is that the oil cooler tube will be below the bottom radiator mounting cross piece and you'll have fitment problems with the plastic air dams...but nothing that a dremel tool, or extra washers won't fix!
I'm thinking that the best dimensions might be 28'' long by 8 inches high. That would be just long enough to route rubber or silicone elbows around the radiator, without being tall enough to screw up the AC or the oil tubing......
The tube-and-fin IC in that link would probably work OK, but look for bar and plate if you can. There's a definite weight difference, as tube and fin is much lighter, but the mass of the bar-and-plate IC helps it act like a heat sink. I was looking to have one custom made by Bell Intercoolers, with the collection tanks on the top and bottom and the core arranged vertically (like a Procharger) but the minimum height was around 10 inches....
|04-26-2004 05:50 PM|
|04-26-2004 05:30 PM|
Okay I tracked down the thread I saw the custom FMIC on. Here is the link (its on Saab Central btw)
If anyone PMs the guy who bought the intercooler about the company he bought it from...please post your findings here.
|04-26-2004 05:29 PM|
|snow4_1man||Thanks Mike, you know your stuff. I pulled that pic from Saab Central. Going back and checking it out, good correction your right itís Spearco. He even posted a site were he has his install. (http://www.vlphotos.com/saabvigic.html) While looking at the bar I see on the bottom, you think that bar can just be bent downwards?? If you bend it down just to move it out of the way. I don't know how hard that would be, because Iím not about to sacrifice my A/C. If that is possible to do, could you get an IC that would able be more then 6" in height? Let me know what you think.|
|04-26-2004 04:58 PM|
I have a Viggen unit already.
That pic from speedparts if for the 9-3SS
I actually haven't payed off my head yet. I still owe $288 on it.
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