Intercooler Options

[zsn0w]

I'm rebuilding a 1g 7 bolt to swap into a '74 Colt. I'm running into problems deciding which intercooler setup is best for me. I don't plan on ever going over 300 HP or so, and more realistically, I'm thinking around 250 is where I want to end up. After reading about pressure drop from FMIC setups on lower boost/smaller turbos (I'm going to be using a 14b, probably around 15 PSI), I decided to drop the idea of getting a larger front mount like a Mishimoto. Are there any smaller front mounts that I'd be able to use that would work well for this, or a good side mount? I don't think a supra side mount would be good for this (or within my budget), but correct me if I'm wrong. I'd rather go with a small FMIC than a side mount due to the mounting location options in the Colt, but I haven't seen any of the size that I'd need to avoid pressure drop, so if I have to go with a side mount, I can make it work. Thanks!

 

[We're on Boost]

If you are talking about pressure drop from a large intercooler with a small turbo, then I kind of guess that the pressure drop you are talking about is due to the small turbo having to fill a large volume, which it will do, but more slowly than it would fill a smaller volume. So you want a small volume intercooler? Normally when people talk about "pressure drop" they are talking about resistance to flow, rather than volume, so I'm not sure which problem you are talking about.

Anyway, I would think that one of the short "street" type FMIC's would be good. Like this 7" tall one from ETS:
https://www.extremeturbosystems.com/ETS-90-94-Eclipse-1G-DSM-7-Street-Intercooler.html

The 3" thick version would have a pretty small internal volume, still with nice low restriction to flow. Seems like it would be pretty ideal with a 14b.
As far as how it would fit on your 1974 Colt though, I would have no clue about that!

 

[zsn0w]

Thanks for the advice! I was talking about the volume problem you mentioned, yes. Your post made me consider something I hadn't, as well. Shorter piping and smaller internal volume of the intercooler both reduce this problem, correct? The piping to add in a front mount would be substantially shorter than any side mount installation I've been able to figure up in my engine bay. That would mean that the lag induced by the larger intercooler could potentially be offset by the shorter piping to some degree if I'm lucky? Obviously, you can't really give me a concrete answer without a detailed description of what the setup would be, but I'm just wondering if I have the volume problem understood correctly: the longer the air charge has to travel between turbo -> intercooler -> intake, the longer the lag period. I haven't measured, but I've got a little space in front of the radiator before the grille. I believe a 3 inch core will fit, so I'll just have to fab up some sort of mount adapter, and an intercooler of the style you linked should fit fine! There are holes next to the radiator, so hopefully there will be little cutting required, too!

 

[silvreclips]

In my experience, a larger core and longer pipe route have a miniscule effect on spool. I have removed the entire intercooler and ran the turbo right to the TB and didn't see much of a decrease in spool time.

I would rather have a core that doesn't heat soak quickly, and I can beat on without the intake temps shooting way up.

 

[We're on Boost]

I'm just wondering if I have the volume problem understood correctly: the longer the air charge has to travel between turbo -> intercooler -> intake, the longer the lag period. I haven't measured, but I've got a little space in front of the radiator before the grille. I believe a 3 inch core will fit, so I'll just have to fab up some sort of mount adapter, and an intercooler of the style you linked should fit fine! There are holes next to the radiator, so hopefully there will be little cutting required, too!

It isn't so much the length of the piping, it is almost entirely just the total volume of the entire space that has to be pressurized whenever the turbo is called to action that counts as the "volume" problem. So this would include the volume of the piping and the intercooler internal volume. I think this is a small problem actually, because the lag added by a larger intercooler is not going to be much, but it is going to be some.
Short route piping is good, but mainly what makes it good is less drag on the airflow, which is another way of saying less resistance to flow.
That factor (resistance to flow) is where you want the diameter of the intercooler piping to be reasonably large, and you want the intercooler itself to have low resistance to flow internally, and larger intercoolers have less resistance to flow, given equally good design details. So there you have the "volume problem" and the "resistance to flow problem" at odds with each other.
Usually the specification that is intended to tell you resistance to flow is one that reads like "XXXX cubic feet per minute of airflow at X.X psi of pressure drop. I don't always see a spec for that on every cooler but these ETS intercoolers are pretty well designed, and some other brands are about as good. So that pressure drop at a given flow rate is something they look at and should be something they consider when they give the thing a horsepower "rating" or "recommendation".
If you have more pressure drop at a given flow rate, then the turbo has to work a little harder to

My only experience with the "short" street type front mount intercoolers was a friend who had a Nissan S-14 drift car that had turbo and hp about like what you are looking for. It worked really well, was fast and fun to drive. He had one about 7" high that fit under the crash beam so that the crash beam didn't have to be removed. He really liked it because being short, it doesn't block the radiator as much as a full height FMIC does, so your basic engine cooling is better.
If you are trying to get the absolute maximum power out of the turbo (even a small one) then a big intercooler is still the best. Also if you are going to do long runs, like a track day on a road course where you can go out and flog your car for 45 minutes, or even if you just want the best possible 1/4 mile drag time, then a big intercooler is still the best. But for all things considered, on the street with a 14b, and realistic hp expectations, a "street" type intercooler should be a good way to go.

What about making the piping for it? Are you going to do that yourself?
One thing I would probably do is mock up the whole thing on your car before you buy anything.
I would make an engineering type sketch of the intercooler rear view and draw in dimensions every place that I would want them, leaving a blank space where the number of inches would go, scan it, and email it to them and ask them to fill in all the blanks! Then you could make like a full-size 2-D (flat) mock up of the intercooler and play around with it on your car to see how everything lines up. I think ETS would be cool about doing something like that if you called them on the phone first about it. Maybe they have a dimensioned drawing already that they could send you.
You would need overall length, overall height and thickness, dimensions to locate the inlet and outlet positions and their diameters, and the whole shape of the periphery of the thing dimensioned so you could copy that onto cardboard, or foam sheet or something, and cut it out. Seems like that's the least they could do for you, since they don't offer a piping kit. It would be pretty simple since it is all straight lines and angles and circles. No fancy curves anywhere.

 

[zsn0w]

Ah, thanks for the explanation, that makes sense. I've heard great things about Mishimoto, know if they're as good as people make them out to be?
For the piping, I am deciding between cutting pipe straights and corners to the right lengths myself and having it welded (the less rubber+clamps connections, the less resistance to flow, correct?) or finding an exhaust shop that can fab the piping for me. I'm leaning towards the more DIY method, as that's how I've done almost everything on the build so far. Great idea about asking for detailed dimensions on the IC, I'll definitely do that now. I'm thinking I may mock it up with some kind of flexible tubing to use as a reference, like a dryer exhaust tube.

 

[We're on Boost]

I've actually never looked into Mishimoto stuff so I wouldn't have an opinion about that.
I think you could cut and fit all the piping pieces yourself and have it welded up by a shop. Normally though, you would probably tack weld the pieces in place when you have all the cut pieces positioned correctly in the car, then take them out to do the final welds. It's tough, if you aren't an expert fabricator, to get it right. I've done a lot of fabricating with thicker metals that are easy to work with. Something like this I would consider to be a pretty tough project.

For low resistance to flow in the piping, I would say the main thing is the quality of your bends. You would want all of your metal bends to be mandrel bent so they are smooth and they stay circular in cross-section all the way through. I'll post pictures of the kits that ETS used to sell, when they sold piping kits, which annoyingly they don't anymore, for the 1g DSM . You can see that the bends in the piping are smooth mandrel bends and they are long radius bends when they can be long radius, for least resistance to flow. In some places you will probably have to use a short radius bend and that's just the way it goes. You have to do what fits. I would avoid doing any "pie section" type bends. Either smooth mandrel metal bends, or rubber elbows.
If you look at the "photos" tab in my profile here, you will see that the final bend going into my throttle body is a very short radius bend and it is a rubber elbow, not metal. It works and it works pretty good!
An exhaust shop, I don't think the typical muffler shops have a proper mandrel bender. You can buy good quality pre-bent sections that are mandrel bent and then cut them to the length you need, but they aren't cheap, especially if they are stainless steel which is kind of the material of choice for intercooler piping.
You can use rubber elbows for some of your bends, the high quality silicone rubber ones that are made for boost applications. They are available in 90 degree and 45 degree. In places where you need a short radius bend, a rubber elbow is probably about as good as a metal bend, because bending metal smoothly becomes more and more difficult as the bend radius gets shorter, and the airflow around a short radius bend is going to be a little rough anyway, no matter how smoothly the bend is made. If you want to fab it up yourself as much as possible, you could probably avoid some of the difficult fabrication by using rubber elbows in more places and metal bends in fewer places, and probably save some money that way too.
Take a look at those hose clamps in the ETS pictures, and in my pictures. Those are good clamps. You can tighten the heck out of those things because they use high strength steel alloys and are a good robust design. You don't tighten those with a screw driver, you use a box end wrench!

Hmm, Cincinnati. The shop I like in that part of the country is Pure Tuning in Toledo. I actually bought my Shearer Fab stuff from Keith at Pure Tuning, rather than from Shearer directly. Keith is a great guy and if their shop is still the same as it was, I would say they could do fab work for you at a reasonable cost, and it would be good. Not cheap, but not overpriced. I bought my exhaust manifold from him way back in about 2008 or so, and it just finally went on my car in 2016. They are about the same distance from you as English Racing is from me, and that's where my current project was done.

The "14b" version of my car had an upper intercooler pipe made from ordinary mild steel that was welded probably with a wire welder. It wasn't painted, so it didn't look very good. It worked. The bends were good smooth mandrel bends. My normal "high boost" setting with that car was only around 15 psi, but I did experiment with more and that wasn't really very good because I still had the stock sidemount intercooler on it.

Here are the ETS kit pics - these are from about 2008!
One pic shows the 7" tall "street" model, the other one shows the "race" model.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

 

[pauleyman]

Why does everybody get so bent out of shape about volume? 10 feet of 3 inch diameter pipe Plus some very large end tanks on a 12 inch tall intercooler are still barely more than half a cubic foot.

 

[Mello]

My thought as well. When you consider the piping is the same regardless of what size the intercooler is, a 14b will fill the intake in a hundredth of a second or two & the difference between the small verses large intercooler maybe a fraction longer. I've logged hundreds of hours (like hundreds of MBites) with side mounts, front mounts & really big front mounts, running t25, 16g, 20g, 60-1/P-trim, & ZO4 & never could find data to support the intercooler size spool myths. The best advise I can offer is the cooler the intake air the better off you'll be. The larger the intercooler the longer AIT's will be kept down till heat soak. Not all intercooler core are equal (like raditors) & you get what you pay for.

 

[We're on Boost]

Yeah I think the volume "issue" is really a very small one and that the other factors are more important. Having low resistance to flow (low pressure drop) and being able to reject a lot of heat to the ambient air, those are the main things, and larger intercoolers of course do those things better.

 

[pauleyman]

Yeah I think the volume "issue" is really a very small one and that the other factors are more important. Having low resistance to flow (low pressure drop) and being able to reject a lot of heat to the ambient air, those are the main things, and larger intercoolers of course do those things better.

I don't have logged data but I doubt the issue is even small. I'm thinking like insignificant and unmeasurable and as mentioned above a myth. Lag is caused by other things.

 

[boostdawd]

Vrsf intercooler kit. Hands down best bang for the buck.

 

[We're on Boost]

Vrsf intercooler kit. Hands down best bang for the buck.

This one? http://www.vr-speed.com/performance...it-fmic-90-94-eclipse-talon-turbo-1g-dsm.html
That looks pretty interesting! $310 for a kit that includes a bunch of piping, rubber elbows, and clamps. What strikes me just looking at it is, maybe it would be better than starting from nothing, even though it is not for the exact car (74 Colt). With some changes to the piping here and there it might be a good starting point.
They have proper beads at the ends of the metal pipes, and the clamps look good.
Then the J-pipe is an extra $55 and a different BOV flange of your choice is about another $30. Not bad.

 

[GST with PSI]

A sudo-outside the box approach could be no intercooler, and instead used methanol injection. Depending on how you intend to use the car, it could be cheaper and easier to setup and use. Water injection (rather than meth) could even suffice at sub 300hp power levels depending on the fuel available in your area. Food for thought.

 

[boostdawd]

Yes sir thats the one. I was able to get 380whp so far from this intercooler on 22-24psi from a e316g running e85 on a conservative tune.

You have a point. Or maybe even a liquid intercooler. Maybe overkill but if you have space on the engine bay why not.

 

[We're on Boost]

Yes sir thats the one. I was able to get 380whp so far from this intercooler on 22-24psi from a e316g running e85 on a conservative tune.

That sounds real good. In fact, looking at your 16g car, that is almost exactly what I wanted to do with my car when I first got it. But I always needed the time and the money for something else so I never did
Then I retired and that changed everything

If you got your evo 3 16g from FP, that was probably several years ago right? I sort of thought those turbos became hard to get recently, but I notice now that Extreme PSI is selling them for $849. They say "This is the REAL Mitsubishi EVO III 16G coming directly from MHI." Do you happen to know if there is anything funny going on there, or are they for real?
https://www.extremepsi.com/store/product.php?productid=16296

 

[boostdawd]

That sounds real good. In fact, looking at your 16g car, that is almost exactly what I wanted to do with my car when I first got it. But I always needed the time and the money for something else so I never did
Then I retired and that changed everything

If you got your evo 3 16g from FP, that was probably several years ago right? I sort of thought those turbos became hard to get recently, but I notice now that Extreme PSI is selling them for $849. They say "This is the REAL Mitsubishi EVO III 16G coming directly from MHI." Do you happen to know if there is anything funny going on there, or are they for real?
https://www.extremepsi.com/store/product.php?productid=16296

Yea I bought it from them a few years back. Got it for 500 brand spanking new and looking like a gem. Best purchase I ever made.

There is a lot of knock offs on ebay and since this is a sorta rare turbo nowadays that's why the price is pretty high. MHI turbos almost 30 yrs old are a dime a dozen.

But if you want an awesome street machine u can't go wrong with this turbo. And e85 makes it so much better. I'm not a great tuner by any means just know the basics. Im sure someone with the skills can easily make over 400 with this thing. Torque is insane in such low rpm and full boost smacks in the mid 3k. I was able to get about 37-40lbs/min on a cold night.

 

[We're on Boost]

I remember the $500 price on those things. But even at ~$900 I'm glad just to know that they are still readily available brand new and genuine from a well known dealer in the USA.

 

[19GSX92]

Vrsf intercooler kit. Hands down best bang for the buck.

+1 just installed the VRSF FMIC running the stock 14b it spools fine but as mentioned don't know how well it will fit on a colt.

 

[We're on Boost]

+1 just installed the VRSF FMIC running the stock 14b it spools fine but as mentioned don't know how well it will fit on a colt.

Thanks!

 

[Airsign89]

Another option regarding intercoolers is to look at used OEM IC's like one from an Evo. They are abundant, cheap(saw a local CL ad with piping and the good Metal BOV for $120)
should easily support 250-300chp and shouldn't block airflow to the radiator as bad as a giant aftermarket unit. Just a thought.

 

[92AWDHX40]

Gonna upgrade so thinking about the ets. And see how she runs on new e 85 set up.

 

[zsn0w]

Thanks for all the information everyone! That VRSF kit looks awesome for the price. I'm thinking I'll either go with the small mishimoto I've been looking at or the VRSF since it comes with all that piping and I could adapt a lot of it to my needs. I was actually thinking about doing a water intercooler at one point since I have so much room in the engine bay to work with compared to a lot of cars, but I decided against it because, from what I read, it seemed like it wouldn't be particularly advantageous in my setup. We're on Boost, thanks specifically for all the help. I'll definitely take all of those suggestions you've given me into account when going through this process, and I'll contact the shop you mentioned to see what they can do for me when I get to that point. All the information you've given me is awesome and will be super helpful going forward. Everyone also keep in mind, the opening in the front of the Colt is not huge, so part of the reason I wanted to run the smaller IC instead of a full-size one was to allow less of the radiator to be blocked. This car will be more for cruising around than making insane numbers or tons of pulls in succession. Thanks again everyone, this forum is amazing as always.

 

[We're on Boost]

Good luck with it!

 

[skunkprodigy]

that 7" tall ets street model fmic looks like a nice start for the project