ZLover4Life

For those of you who know me, you know that I'm on my second TTZ and you probably know a bit about my last one.

For those of you who don't know me, my first Z was a 90TT 5-speed (just like my current one) in Aztec Red with a Wings West fascia and Stillen Type-III spoiler... here's a pic...



Well, the car was decently equipped...

K&N Intake
HKS Hi-Power cat-back
Specialty Z Split Flange Downpipes
JWT ECU (555/SP Program)
Nismo 555 cc/min injectors
HKS GT2530 Turbos
Apex-i Super AVC/R Boost Controller
JWT Flywheel
JWT Street Clutch

+ some other minor mods, suspension mods, and brake mods

Needless to say, the car was fast, but it wasn't as fast as it should've been. Here are my dyno charts...





403.1rwhp/416.6rwtq at 17psi
431rwhp/400.3rwtq at 20psi

I've seen cars with Sport 500 turbos make those numbers. And the jagged peaks aren't comforting either.

Initially, I accredited the absence of higher numbers to the crappy K&N cone filter, stock intercoolers, and stock catalytic converters. I instantly replaced the K&N intake with a JWT Pop Charger (noticed a difference) and swapped in a pair of Ultimate Z Test Pipes (noticed a beautiful difference in turbo response). I couldn't justify the cost of intercoolers though, but either way, the car should've made more power, and the curve shouldn't be that jagged (compression was fine).

Well, tonight, I was preparing to sell the stock intercoolers off that car when I realized something.

I don't ship parts to people unless I'm sure it works, so I pressure tested the intercoolers. While the driver's side held pressure just fine, THE PASSENGER SIDE INTERCOOLER HAD A PRETTY DECENT SIZED AIR LEAK where one of the plates had been punctured by a pebble. That explains it!

The number are low because I had a massive boost leak. The curve is jagged because half my engine was running rich! (For reference, torque dropped off because the intercoolers get heatsoaked very quickly.)

Even before that, when my car was just a K&N intake, Borla cat-back, and a JWT ECU with boost jets at 16 psi, it only ran 14.172 @ 99mph in the quarter mile! That's slower than stock! And I was pulling down 2.0 60' times on street tires, so I know it wasn't my launch. A punctured intercooler explains that as well.

While I am relieved that I now know the cause of the low numbers, I'm irritated that I didn't discover it sooner. I told the guy interested in that intercooler that I'd give it to him for the cost of shipping and he could weld the puncture closed; it'll work fine, but I don't make any money off that, which also sucks.

So let this be a lesson to everyone... if your car isn't performing like it should, and you've checked everything else, pressure test your intercoolers. After about 10-16 years (if you have stock intercoolers), don't be surprised if just once a pebble flying off the tire of the car in front of you on the highway punctured an intercooler on you.

Now I get to be concerned for the Stillen's I have on the way... how can I protect them without restricing airflow? A Stillen intercooler isn't a cheap thing to replace... but there's no way to protect it without drastically decreasing performance, so I just have to hope for the best.

silvrhand

well you would think it had to be debris cause rocks would more than likely hit the wheel well unless you are driving in reverse really really fast

ZLover4Life

... where did I suggest that it was a pebble off the wheel of my own car?

And considering it was on the front of the intercooler, it clearly couldn't have been from my own tire.

Fast240Z

Forgive me if this makes no sense, since I'm just a S30 guy, but why not put chicken wire in front of the intercooler? I'm not too sure exactly where the intercoolers are on a 300ZX, but I'd imagine there'd be a way to protect them somehow.

silvrhand

Just bad reading it's late and I skimmed it.

As for the hole it would probably just a bad luck I would imagine it would take a pretty decent sized rock to do damage like that, how big was the hole?

ZLover4Life

Considering the overall surface area of the actual wire in chicken wire, I don't think it'd help much. Perhaps I'll try it, but that's only going to stop debris that is larger than the opening in the chicken wire. I'm not 100% sure, but I suspect whatever did that would've made it through the chicken wire (the concussion in the fins appears to be about 6mm across). And for future reference, the intercoolers on the Z32TT are sidemounted, hiden behind the gills/openings on the sides of the fascia.

I figured it was just a misread, I just wanted to point it out. I just took my micrometer to it, it's about 4mm across. I'll see if I can get some clear pics of it. It's obvious the plate was damaged, but I wasn't sure if it was punctured until I pressure-tested it.

Riz Z Speed

interesting that it's a puncture, you'd think with the plastic end caps that the plastic/metal joint would be the weakness.

snwbrderphat540

my buddy and his DSM he has a large FMIC he protects with chicken wire sorta, its likea screen door mesh but its made of metal. it catches bugs all day long. but it works good, so far.

ZLover4Life

Where would I get something like that? That'd be exactly what I needed. Can I assume Home Depot would carry it?

91zxtt

You assume correct. Isle 2.....barbed wire, chainlink and t-post fencing.

silvrhand

I would think that anything that is worthwhile enough in stopping something like that is going to disrupt and create some pretty bad air turbulence in front of the intercooler.

Just get the jspec front end! You know you want it.

ZLover4Life

I just dished out $2300 on other parts... whether I want it or not, it's not happening. Besides, I prefer the look of the Stillen Type III front lip.

You are right about turbulence... that's the tradeoff. I'll deal with that rather than having to replace a new Stillen SMIC, though.