TheGloriousTachikoma

I'm planning a tentative turbo swap, hopefully within the year on my S5. I don't plan on going higher than what the stock turbo puts out (around 250whp). I've been looking at the 'show your engine bay' thread and I'm seeing all these FMICs, and the common link is that every one adds at least 8 feet of piping to the intake tract on top of a huoooge [read in Jezzer's voice] intercooler. I can't help but think that this has to kill boost response, or at least maim it somewhat.

This leads me to another question, of where does the hot air go after passing through the TMIC? It can't go up through the back gap of the hood because of the high-pressure zone of the windshield. It seems that it would just aggravate underhood temps. As well, as the throttle body sits under the TMIC, wouldn't it just partially re-heat the intake charge.

I had the idea of remounting the intercooler sideways by where the factory airbox sits. Mount a cone filter on the turbo and place the MAF where the TMIC normally sits. Then it's a matter of mounting a small fan to the intercooler and ducting it's air supply from the fender. The exhaust from the IC then joins the radiator exhaust and leaves the engine bay through a vent in the hood.

Solutions to problems that probably don't exist in the first place aside, are there any potential performance benefits to turbocharging the NA engine over the TII? I have read Aaron Cake's writeup on the process and understand it's relative difficulty and need for custom fabricated components. But, it seems that the complicated intake piping of the NA would yield more efficient induction than the TII manifold, and thus deliver greater MPG. Or, would enough fuel need to be injected to compensate for the NA's higher compression ratio that any gains in efficiency would be negated?

Thanks for the time.

barkz

iTrader: (1)

i noticed higher temps(according to my stock gauge) but nothing noticable as far a boost response, after i put my FMIC on. but i also have a full racing beat revII and all aftermarket intake parts too. in the future i plan to make ducting, or just go vmount to fix the higher temps. but ive driven it in cold Jan air and hot May (almost 90*) air and it didnt over heat.

AGreen

iTrader: (11)

Let me tell you now, I started having cooling issues with mine after installing a FMIC. The "exhaust" from stock TMIC flows out the transmission tunnel, just like the rest of the air passing through the radiator. I installed a larger aluminum core radiator and have never had any issues since with cooling. Then again, I also v-mounted it when I installed the Al radiator.

If I had to do it again, I would have gotten the RIGHT radiator for the car (it's a long story why mine is wrong...) and left it with the FMIC, the "8 feet" of piping, and called it good.

RotaryRocket88

iTrader: (7)

The TMIC has a heatshield on the bottom that directs the airflow down/back through the transmission tunnel area. The biggest problem TMICs have is heatsoak while sitting at a light, etc... While moving, the IAT temps I've logged over the years w/ a stock turbo & TMIC are really not that bad. But if you sit for a long time, the TMIC heatsoaks and becomes less able to remove heat if you get on the throttle soon after. On my car, which now has a hybrid turbo, I'm setting up water/meth injection to make up for the TMIC's heat-rejection short comings.

A properly done high compression turbo can make more power than a TII engine, but it requires careful tuning (primarily less ignition timing). If you just slap an SAFC on it and dial up the fuel a ton, it's not going to be worth it.

Edit: I see AGreen already mentioned the TMIC airflow.

florotory

When I did my FMIC i was worried about all the above, hot days in FL,boost response ect. I didnt notice hardly any lag in boost and the car ran a normal op temp. Id advise you to flush your coolant, and keep up on the maint. A lot of times when people have problems with the cars its due to improper maint. (not all the time).

TheGloriousTachikoma

Yeah...what with I have planned down the road, airflow down under the car is counterproductive. But then again, 250hp probably wouldn't be enough to take advantage of active ground effects. Or would it...? I think if I retained the TMIC then I'd just rig a gallon or two of water and set it to mist the thing whenever intake air temps rose above a certain threshold. But then again, my idea for intercooler placement negates the need to purchase a TII hood, and giving the IC it's own E-fan also solves, or delays, overheating.

But such is the advantage of theory and armchair fabrication. And RR88, I'm thinking in terms of fuel economy, not extra power. If I can't get better mileage from a 250whp NA-Turbo than a 250whp Turbo-II, then it isn't viable anymore.

Heck, I'd be better off doing the swap, and trying to fit a Pruis's motor between the trans and the engine...

sharingan 19

iTrader: (16)

Actually a N/A-t setup WILL net better fuel economy because the higher compression rotors are more efficient anytime you aren't in boost. Also, I'm not sure what your plans are for the car, but response is greatly improved as well.

All front mounts don't have to be huge and attached to 8ft of piping. The mistake most people make is getting ridiculous (17x27x4) IC's rated for 2x the horsepower they will ever make, then they do nothing to duct them and wonder why they can't control their engine temp. The Corksport FMIC routes the piping more efficiently and is certainly shorter than 8ft. If all you want is the stock turbo, then you don't even need a large IC at all. A small (8x20x2.5) core will be more than enough and be easy to mount.

As RotaryRocket pointed out, you can make up for the shortcomings of the stock TMIC w/ AI but its hardly worth the effort/expense with the stock turbo. A V-mount would be the most efficient setup , but that is likewise overkill for your goals.

You mentioned doing some kind of SMIC (side mount) setup with a fan and such; by the time you run the piping for that and fabricate the ducting necessary for it to be even remotely effective you might as well upgrade to a more efficient core and run a front mount.

TheGloriousTachikoma

I took a look at the Corksport FMIC and it seems to need just as much piping as all the ones I've seen. And even if it's alot of work, my side-mount idea would need only a few feet of piping total. I'm just remembering how much pipe Aaron Cake had to run when he turbocharged Tina and am irrationally fearful of long length of pipe in a turbocharged engine. And hey, a NA-T would put the TB and compressor output fairly close.

I've also found a very substantial strike against the TMIC. The TMIC doesn't work with a Taurus alternator apparently. And with what I have planned...well, the Taurus Alt may not even be enough, lol. An E-fan and semi-conformal-podded, roof-mounted aux lights will consume all a Taurus alt can provide.

Of course...going NA-T means I'd have to bite the bullet and rebuild my engine first. And replace the oil injectors

sharingan 19

iTrader: (16)

"Irrationally fearful"...yep. If the piping diameter is kept in check then response won't suffer significantly. Additionally the N/A-T setup has increased response, such that even with a front mount, it will spool at least as fast as a stock TMIC TII. However if you are that afraid of piping, just run a water to air setup.

You mention the TB being close to the compressor outlet (that's only if you use the n/a manifolds which work, but I found it more effective to use the turbo manifolds). If you went with a AI only setup, you could run a pipe directly to the TB w/ no IC at all, that's what, 14" of piping?!?! Although, that would place your piping directly over the turbo, so you would probably need to devote some effort to sheilding the turbine housing (one of the reasons I prefer the turbo manifolds)

A few more amps are nice, but damn that taurus alt is ugly. Roof lights....? what exactly are you planning?

HOZZMANRX7

iTrader: (43)

This all seems like an awful lot of over thinking......................

TheGloriousTachikoma

Let's just say that by the time I call Lucy "complete", she'll be sharing a very key design element with the Chaparral 2J. If that doesn't need it's own APU, it'll need it's own alternator at the least. The roof lights are just a whimsical idea I had and hard to describe.

If this was a race car then AI would be ideal; less weight in intake tract bits and less to leak or go wrong. But it's a street car and I'm sure that even by the drum isopropyl is expensive. And a hassle to keep full. the problem that I see with the TII manifold is that the angle into the block is rather severe to clear the turbo, correct? It seems that fabricating an adapter, or as Aaron Cake advises, a new exh-manifold, allows for the stock int-manifold (albiet with the bypass valve and aux port actuators removed) to be used. Perhaps room for a decent heat shield too.

And HOZZ, that kinda defines me. I think up all these great solutions to problems that don't exist, and then spend even more time figuring out how to make those problems in the first place.

jackhild59

iTrader: (7)

Troll?

TheGloriousTachikoma

Uhh...no. Maybe a little exuberant and naive, but not a troll.

jackhild59

iTrader: (7)

Ok, just checking! Thought maybe you were having fun yanking our chains.

Good Luck!

driftxsequence

iTrader: (8)

AI is not just "for race cars" it's a more common thing to see now because it allows you to extract more power out of the turbo by altering its compressor map slightly, allowing more boost to be run SAFELY! Hell..I'm gonna run it on my 6 port turbo with a hybrid turbo. I'd rather not blow my engine while learning to tune myself!

TheGloriousTachikoma

I never said AI was for race cars only. I just said AI was ideal for track-only machines and less than ideal for a daily-driven car. Relying on AI only for intake charge cooling would require constant attention beyond even normal RX7 care, not to mention the possibility of one being unable to refill the tank. I have yet to find a gas station that doesn't sell 2-cycle oil. I have yet to come across a conveniently accessible retail store selling isopropyl by the gallon.

FC3S_nataku

iTrader: (3)

you dont need to run meth to have a effective AI system. most people run distilled water preturbo and have great results.

*Ninja edit*

here is a link you can read up on

https://www.rx7club.com/auxiliary-injection-173/pre-turbo-wi-vs-post-ic-wi-dyno-test-results-987107/

Digi7ech

iTrader: (1)

For all the people saying they're having cooling issues once they went FMIC, do it right!

Ducting is 80% and then placement of the IC. I put foam in the corners around my radiator.

I sandwiched my Isuzu NPR up against my Koyo radiator. I have maybe 3-4 feet of piping at most. It was 1 U bend pipe cut up and a straight piece.

I run a Taurus Efan on my car and run at 180 driving around town on low speed. Once it starts hitting 100-110 out here, I'll switch it over to high speed. I've done full throttle 20 minute track sessions without overheating.


Thread to install when i was still clutch fan.
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/installing-isuzu-npr-fmic-782097/

TheGloriousTachikoma

I'll hand it to you Digi, that setup looks pretty sweet. However, that's without the AC condenser. I'm not sure if, when I do a turbo/swap, I want to remove the AC or get it converted to R134. Of course, you seem to manage summers just fine in a black car, I can't remember a MI summer hotter than high-90s. But I digress...

sharingan 19

iTrader: (16)

<iframe width="420" height="315" src="http://www.youtube.com/embed/rWzUsW18k3c" frameborder="0" allowfullscreen></iframe>

WTF


Stop for a second and think about what you are suggesting here....

Seeing as how that setup makes the exhaust (aka HOT) side of the bay more cluttered w/ piping, the n/a LIM is more bulky, and is oddly shapped.......I'd have to say wrong on all counts there.


Hey, you finally got one right!

THIS.
You are a walking contradiction and will most likely only be tolerated/ appreciated in the lounge.

FC3S_nataku

iTrader: (3)

Brigdh

iTrader: (9)

So, while this great thread exists and is active, I'd like to get some feedback.

I have a stock S5 TII that I am prepping for autocross. The class it is running in allows any intercooler setup, so long as I don't cut into anything. I'll be removing AC, but I need to keep power steering, the stock turbo, and cannot touch the wastegate.

Would it be worth it to go FMIC, or would I be better off soaking the stock TMIC in water between runs?

barkz

iTrader: (1)

for a FMIC(of the shelf one) in our cars you need to cut holes under the headlights and cut/remove the bumper support.

Brigdh

iTrader: (9)

I was thinking something custom. Everything else I'm doing is ending up custom.

TheGloriousTachikoma

Yeah, I get that alot. I also recognize that active ground effects are only practical on a race track and even then are sensitive to ground clearance and I may off the track and kill myself for something as simple as jumping an apex curb.

My issue with the turbo intake manifold was that the sharp angle into the block would decrease efficiency. But I think that may be an insignificantly small variable at this point. Perhaps a more relevant question would be how well the turbo intake manifold ports match to the NA ports.

The more I look at Digi's intercooler the more I like it. But I just looked-up the Isuzu Elf/NPR. I doubt I'll find that particular truck in the area. But then again, similar turbodiesel trucks will have similarly sized intercoolers, no?

And Nataku, lol.