TrevorS

iTrader: (1)

I read that typically, under 10 PSI supercharged cars doesn't use an IC (the TRD bolt-on for example). Are there any particular problems with going 4-8 PSI turbo without an IC?

Supra12big

iTrader: (1)

Well you gain more efficient power at lower boost levels. Supercharges that don't fun a intercooler setup, tend to heat soak quite quickly, and that increase's chance of detonation and possible knock.

Your answer is, just get a intercooler.

brainneeded_

wrd. it's like an extra 400-500 bucks to save your engine.

TrevorS

iTrader: (1)

If manufacturer's sell IC-less vehicles with superchargers in this range, then given they are providing warranty's, how much risk can it be? Is inclusion of an IC for low PSI turbocharged vehicles paranoia? Or is something else coming into play?

oreoremix42

Thats a good question.

Did you find a SC for sale? I found a TC supercharger for sale. Are they the same?

ScionFred

iTrader: (1)

Just a lot of variables. Some people run a huge FMIC but put the intake air filter where it draws really hot air from behind the radiator. Expect a lot of canned responses like the ones below to questions like this at SL:

"Don't boost on a budget"
"You gotta pay to play"
"Get a tune!"
"You'll blow yer engine n00b!"

Of course you could safely turbocharge a 2AZ at 4-8psi w/o an IC but it's not as easy as setting the wastegate to < 8psi. The big problem in duplicating what the oems can do is matching their R&D resources. Which is why garage builders like us should play it safe and conservative.

Personally I wouldn't worry at all about running a small turbo at 6psi w/o an IC but I'd install 1-step colder plugs, a 160F thermostat and orient the air intake so that it draws the coolest possible air to start with. You could always eliminate the need for a IC with WMI too.

Lots of variables...

Is this something you're contemplating doing?

FromTheOld

Intercoolers are meant to cool air, because when air is compressed it gets hot. Most theory suggests that at low boost on a small turbo, not a lot of air is getting compressed which means it's not going to get THAT much hotter, but you can easily buy an eBay intercooler + piping and have it setup for under 200 bucks. There's no downside to running an intercooler. It makes your car safer to drive due to less heat soak/detonation, and it allows your car to create more power due to colder air. It's a win win, unless you count additional cost.

You don't really need a huge IC to begin with if you're not running a big turbo or high boost, but having any intercooler gives you easy future upgradeability.....that's what is most important to most turbo guys.

brainneeded_

ok, realistic answer here. supercharger and turbocharger work similarly in concept (increase inlet pressure) on 2 different methods (belt/fly driven vs. spooling with exhaust gases). while you CAN safely run low LOW boost on either method with some sort or intermediary heat sink (intercooler) between boost source and engine, if you're asking these sorts of questions, it stands to speak that you don't really haven't the foggiest. and when that's the case, wouldn't you much rather run on the safe side, rather than taking some e-stranger at his word? i know that if it were me, and i couldn't figure it out on my own, i'd rather take the safe way than go off a strangers assurance.

just my $.02

also note, too much cooling is not a good thing either. everything in your engine has an optimal temperature range, so don't throw the biggest fvcking intercooler you can find on there either. size it properly for the application. find a local speedshop with a reputation and knowledge and see if they can help you.

FromTheOld

For an intake application, too much cooling is NOT a bad thing. Do you honestly think that there is an optimal "intake temperature range"? But there is no point in putting a huge intercooler due to extra weight, and sometimes, you don't need that much cooling capacity anyway.

Well, I'm not saying you should not run an IC. My previous post explains a few things....so you should have your answer. Save 100-200 bucks for having less power and possible heat soak....or not?

buickid

OEM boosted cars can run without an IC because they're built to do so. The OEM can specify a lower CR, whereas we're adding boost to an engine designed to make power NA. Lower CR = less chance of detonation under boost.

AAG

iTrader: (1)

Heat kills engines, get the IC and prolong the life of your 2az-fe

brainneeded_

you're right, my bad it's been a long day. i was thinking fluid application, i.e. oil cooler and radiator. good catch.

oreoremix42

Why then on my old car. The turbo model if they installed a better intercooler, it lowered HP? It was a 3000gt stock side mount intercoolers produced more power then a larger intercooler?

FromTheOld

I could barely understand what you were saying/asking, but I'm assuming an FMIC lowered the power compared to an SMIC. The answer could be a # of things.....who knows? Outside temperature, intercooler efficiency, tons of things. Plus, we're talking FMIC vs no FMIC, not FMIC vs SMIC. Sometimes its better to keep SMICs because they're better for tracking than FMICs, because SMICs do not block the radiator and allow better cooling, which in turn, in rare cases, might cause the ECU to retard timing if the radiator isn't providing sufficient cooling. Lots of variables, no way to really know

madmarx

If the IC your stock 3000 gt had was achieving a near 100% efficiency, i.e. the outlet temperature of your intake flow is equal to the cooling flow temperature then adding a larger IC will not be able to cool the intake flow any more than the stock IC. Along with the temperature drop you will also experience a pressure drop as the intake flow passes through the intercooler. With a larger IC you will experience a larger temperature and pressure drop. The decrease in temperature will increase the quality if your intake flow while the decrease in pressure will decrease the quality of your intake flow. So for each turbo set up there is an ideal IC that will achieve a maximum temperature drop with a minimum pressure drop and a minimum loss of specific energy.

TrevorS

iTrader: (1)

Thanks !

I see two downsides to installing an IC. One being the cost, the other being the changes typically required to the xB2 appearance. Some might like that, but I can't really say it works for me ! The upside, of course, is you have far more latitude, however, I'm not really that big on power. I've added roughly 100HP to my turbo Eclipse, but have zero interest in going further. The mods thus far allow it to stay very near stock, and I like that ! So, if I were to turbo mod my xB2, I would again want to minimize disruption to the basic layout, and avoid change to its external appearance. A possibility would be an SMIC, but no IC at all is even more attractive. 4-8 PSI would be my sweet zone and so I would be thinking a small Turbo and preferably limited mods to the AFC and etc.

TBH -- I'm merely toying with this idea and I'm in no way committing to it. I'd say it's as much an intellectual exercise as anything at this point !

TrevorS

iTrader: (1)

Can't say I entirely appreciate your input -- not just a little condenscending and presumptive to someone who actually does have some understanding of the subjuct -- though indeed, seriously limited experience.

Please also recognize there is a difference between even experience and genuine understanding and knowledge. What I'm hoping is to tap into the latter !

TrevorS

iTrader: (1)

I understand that. The early Eclipse came with both a higher compression N/A format engine, and a lower compression F/I format engine. However, my point of comparison here is the xB2 with bolt-on TRD supercharger Vs N/A. The CR is unchanged.

TrevorS

iTrader: (1)

Hiya Fred!

Thanks very much for your down-to-earth response, always appreciated ! This is just something I'm pondering. I feel there to be distinct downsides to going turbo (even low PSI), but even so, it's an interesting thought. However, a large part of it for me is just to better understand the technology and particularly the practical differences (if any) between supercharge and turbocharge on autos.

Is there or is there not a difference in the cooling needs between modest PSI supercharge Vs turbocharge on the same engine? (That isn't meant to be a question to you specifically, but just a representative question relative to what I'm thinking.)

ScionFred

iTrader: (1)

Well, in general, superchargers are much easier to tune for because of their very flat, linear boost curve vs a turbo. Also, I believe that MTs are easier to tune for because they don't maintain full boost during shifts. IMO, tuning a turbocharged AT is a lot trickier than tuning a SC MT.

IMO a turbo producing 6psi of boost is going to heat the air charge more than a supercharger producing 6psi due to the hot turbine bolted to the compressor. The compressor wheel and housing are bound to run hotter on a turbo and the intake air is the primary means of cooling them. In a nutshell, you'll need a IC at lower boost levels with a TC vs a SC.

Based on the results of dozens of ZPI stage 0 owners and my own experience, I remain 100% convinced that it's possible to have a relatively safe, inexpensive and enjoyable turbo setup on the 2AZ with a small SMIC or no IC and no add-on engine management. The only caveat is that you'd be limited to about 225bhp with such a setup.

As you may remember, I started my boost project planning to do just this but as things progressed, I strayed from my original path (regrettably so). Here's what I learned along the way:

1) The oem ECU can trim 440cc injectors without even a CEL but it's not ideal. It takes a long time to learn them and runs like crap during that 100+ mile learning phase. 370cc - 410cc would be much better. OEM are ~320CC despite a lot of misinformation on SL saying that they are 370cc.

2) A T3/T04E is too big for a stock ECU setup. IMO a T3 60 trim would be perfect (Treadstone and Ancla agree). ZPI chose the similar 16G but try finding a manifold for one today.

3) It's absolutely essential that you keep the MAF tube as close to oem as possible! 71mm is the correct ID size and keeping the oem airbox would be ideal (Descendant knows this).

4) My car ran great without any add-on engine management after the ECU had enough time to adapt to the 25% larger injectors, 10% smaller MAF tube and 6psi boost. Most of the problems I had were caused by the injectors being slightly too big, the MAF tube being smaller than oem and the T04E producing too much boost, too quickly. Even so, the problems I had with the oem ECU setup were nothing compared to the problems I had with the FIC and harness. The biggest problem before the FIC was a recurring P0101 CEL that had zero affect on driveability or performance.

5) I never had any knock issues at 6psi so IMO the oem ECU and knock sensor work well enough for a low boost/hp setup as detailed above.

6) Where most people run into problems (blowing engines, etc.) is simply pushing a given setup too far. It's very true that you're never gonna make 300whp reliably without a good piggyback and tune but if you can live with ~200whp for ~$2500 (incl gauges, etc.), it's quite possible, IMHO.

BTW, just to be safe, I'd personally recommend a stealth SMIC like mine over no IC. You could do even better with WMI for the same ~$200 but a SMIC is more reliable and doesn't require any maintenance.