Z31Turboed

I carefully looked over the redZ page with all the Intercooler setups. Everyone seems to have their own way of acheivig the same thing depending on their car and the way they set things up.

With the OEM radiator and factory AC it's pretty snug under there. I don't see an "easy" route for the IC pipes.

Seems that one good and efficient way to route an Intercooler (if retaining AC) would be to use a shorter AC Core and Radiator core. Shorter by 2.75 inches on the Driver side end.

The OEM Radiator is approximately 15 x 28 or 420 sq in. Reducing it to 15 x 25.25 would yield 378 sq in. a loss of about 11%
In engine cooling, that could be made up for and likely result in an overall cooling improvement by adding an oil cooler.

The AC core would be slightly smaller, but in the case of the Radiator and the AC condenser, both could be improved by replacing old units with newer, higher efficiency units.

So, if you did this, you'd be left with a nice, 2.75 in (approximately) slot on the side of the radiator and AC core to pass the intercooler pipes through.
One possible problem is needing a 90 deg elbow on the passenger side IC fitting (unless you got an IC with inlet and outlet on one side, which still is essentially the same thing.

It might require some searching to find an AC core that would meet the requirements and some fab work to change fittings but it's doable.
You'd have to use a shorter radiator and AC core by almost 6 inches to have room on both sides for IC pipes to pass. Thats a lot.

Alternatively, a shorter radiator and AC core could be used to leave the required clearance along the top of front edge of the radiator, Anyone considered TWO smaller radiators
joined with connecting pipe to provide a gap for the IC pipes to pass through?

I'm just now beginning to think about how I'm going to route my Intercooler. Has anyone done it this way? I don't really like the through the fender method.
and I'm planning to retain AC...at least thats my thought now although I know removing the AC and all it's components would save weight AND make lots of room.
I may be overlooking something obvious here...I'm just starting to take notes and visualize my setup. So anyone who's been there and done that and
knows the easier / better way can chime in.

I'm just cranking up the idea tank right now to see how I'll tackle the IC routing.

AZ-ZBum

There were two different IC systems back in the day that were able to route their piping without modifying anything in the car. They even retained the stock fan and shroud. You can easily make something fit with a little thought an planning.

Flacster

Once I'm done with my build I would like to run a top mount intercooler setup. Seems like a lot less trouble in my opinion.

260zturbo

That will interesting to see since very little room up top.

Z31Turboed

Yeah, I hear there are a few places you can cut and modify to allow that. Rather than re-invent the wheel, I'm hoping someone can point out those shortcuts. Otherwise, I WILL find them. It'll just take a day extra and a few busted knuckles more.

Z31Turboed

That would be interesting.

In my case, I'm looking to optimize heat exchange. I dont think a top mounted Intercooler will exchange heat the way a front mounted one can unless you're gonna use a huge hood scoop like the WRX.

I think if you boil it all down, the ultimate best setup for performance would be a huge Front Mounted Intercooler ahead of the rad that does not pass the heated air into the engine compartment and has very few bends and is close to the turbo and throttle body. It's damn hard to meet all those ideals however.

A top mounted Intercooler would be sitting right in the hottest stagnant pocket of air in the engine compartment....heat rises. A fresh air scoop right above it would help when moving.

Good luck. Looking forward to seeing your progress.

tonsoffun300zx

or you can get a SMIC which is what im going to do if i don't sell my 88 turbo this weekend.

Z31Turboed

I was looking at all that available real estate behind the Driver Fender.

Is that where you were thinking?

Z31Turboed

I know any of you guys who have installed an IC on a Z31 will yawn at this...BUT...there are still a lot of people who have just joined the Z31 family or have just decided to enhance their Z31 a bit....like myself.

To those folks this might be interesting or useful.

This assumes you are not (yet) changing from the factory (1984 / 1985) factory T3 turbo.

After several days of carefully looking at the 1985 Factory turboed Z31, I can tell you that this car was not designed with Intercooling in mind.

Finding a way to route IC piping in the confines of the engine bay without some alterations or configuration mods is pretty darn difficult.

Here's a short list of things I've found that may (or may not) help if you're new to this....

1). You cannot route IC piping over the top of the engine without lowering the engine at least 1 inch. It will not clear the hood. (Unless you raise the hood or add clearance to the hood.

2). You cannot route IC piping under, around or above a factory AC compressor with the engine in it's factory mounts and factory mounted configuration.

3). Getting the IC piping from a FMIC into the engine compartment and past the radiator, AC Evaporator (unless you remove the AC components) is tight. Some people route the IC piping out to the sides and cut a hole in the fender well and bring it back in through there. Others remove the front steel bumper and run the IC pipes in through the space left by removing the bumper support brackets. Others cut the metal edging along the top of the radiator and run the IC piping in above the radiator.

4). Adding an IC and retaining the AC requires some creativity and is not easy.

If you are considering removing the AC components, you will make this job MUCH simpler in terms of getting the piping from the Compressor outlet and from the throttle body inlet towards the FMIC.

An intercooler with both Inlet and outlet pointing towards the driver side might be less "pipe intensive".

I'm not sure if it's possible to buy IC pipe kits off ebay and make the pieces work without any cutting. Chances are, you'll still have to do a good bit of cutting to get the IC pipes contained in an ebay "kit" to work.

Another thing to consider is that if you eliminate the OEM compressor outlet pipe, there are several hose fittings on it that will not be on the ebay IC pipes. If you want everything hooked back up in OEM fashion, you'll have to modify the OEM turbo outlet to throttle body pipe OR, have an aluminum welder add these fittings to your custom IC pipe.

These are just some observations that I thought might be at least interesting to me before I started my first go at installing an IC on a Z31. Hope it helps a bit. If you've done an IC install, please by ALL means add your comments.

AZ-ZBum

True. But why would you want/need to?FALSE! The HKS and system did just that. It went just over the AC belt hugging the distributor. It then hugged the factory fan shroud as it traveled to the other side of the car and to it's IC.VERY TRUE! This is certainly an option and much simpler than trying to use so many difficult bends and sometimes ovaling a pipe.Correct. Anyone who thinks that there are IC kits for the Z31 that are bolt in operations any more are in for a rude awakening.I guess this would be a good time to insert that "Ummm... DUH?" comment. Helped a friend install the HKS system on his. Have examined the @#*$& out of a Spearco system.

Z31Turboed

I forgot that piping smaller than 2.5" could be used. I could not get 2.5" piping to clear the hood no matter what. No WAY 3" piping would work. Maybe if you used 2" piping it would work?


LOL...like I said, for folks just starting to explore this. Not everyone has your experience with these cars. BE NICE YOU !!!! haha

I sure would like to retain the factory AC...but I'm beginning to rethink exactly why I'm doing this in the first place....to go fast !
I can always take the minvan when I need AC I S'pose.

AZ-ZBum

Considering the stock throttle body is only 54mm (about 2") and it isn't even the bottleneck of the intake system, why would you want 3" piping? I believe the HKS was 2.25" diameter, but it's been a long time since I had it in my hands.

hoov100

Less boost lag, but as you said, their are some BIG restrictors in the system. I would be more concerned with the flow of the IC itself TBH.

AZ-ZBum

Smaller piping means less volume means less time to compress means build pressure faster in the intake.

Lag comes more from the turbine side of the equation anyway.

hoov100

Air charge lag comes from resistance to air flow caused by restrictions in the system. of course you can always go too big though and cause pressure loss between the turbo and intake, and of course you can always go too small and restrict the flow. (just like everything)

GregD had a really good post about this on 3zc, I'll try and find it tonight and post the link.

Here's a good link for the OP to read through.

http://www.are.com.au/techtalk/intecoolersMR.htm