I've been chatting with someone about northstars and transmission controllers and what not, and this happened to come up!

His name's Mike Spidell, and I hope he signs up here! I pointed him this way....

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Ryan - "If you try to follow me, you'd better learn to fly"

Owner of the *only* paddle-shifted, Northstar powered fiero.

Wow, nice!

I'll be foolish enough to observe that this very creative individual, if the engine fits in the Fiero, will loose ALL that valuable trunk space we all enjoy. Ed

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It definitly looks cool, but looks like a tuning nightmare. TT is nice for braging rights, but a single suited turbo seems better to me.

Is this in MN by any chance??

For looks and the wow factor it is great but too much tuning issues balancing them out I prefer to use just 1 big single turbo that is more manageable but if he gets it to work that would be nice.

I prefer one big turbo on mine.

What trunk?

Nice pic. It may look as thou some of us are negative towards the TT4.6 but the replies are from us technical type that know what kind of a bite that is to chew. I too appreciate the work of the twin snails but one is enough for me

Pete

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quote Originally posted by Silicoan86: Is this in MN by any chance??

No it's not. Or at least I don't think so? I'd better ask.

So what issues do twin turbos cause? It seems like you guys are thinking there'd be problems keeping the two of them balanced? If they're both built the same, what would the problem(s) be? Well - although I did notice that the front bank has an extra 20+" of exhaust pipe to go through...

quote Originally posted by ryan.hess: I've been chatting with someone about northstars and transmission controllers and what not, and this happened to come up! His name's Mike Spidell, and I hope he signs up here! I pointed him this way....

What engine management is he using? I notice he has a MAF on the compressor inlet pipe.

Where did he get those elbow/bellows combo pieces?

I think he is in OK, but I could be wrong.

Greg

hmmm, interesting....

btw, rockcrawl...your setup is somewhat similar to mine.....somewhat....

He registered, but isn't able to post yet..... He wanted me to relay this:

Ryan,

I logged into pff but have been unable to post yet so I thought I would relay this through you.

big turbo = big turbo lag
A smaller turbo will spinup much faster than a large one, bringing boost in much quicker. The lag created by the increased piping length from the forward bank tends to have a ramping effect, bringing the boost in smoother and over a longer duration. Tunning is not any more difficult as both turbos feed into a common intake. Balancing is not a problem as the outlet piping to the manifold is kept seperate until they reach the throttle boby, and maximum boost is controlled by two smaller wastegates vs one larger one, again, two smaller wastegates are smoother than one large one.

Hope this answers why two turbos is the way to go.
BTW - I live in Oregon

Mike

At least I had the first letter of the state right!

Greg

Big turbo does equal big lag, but a properly sized turbo means next to no lag. In a fiero, that half second of turbo lag is pretty much a non issue when you have all the torque that the N* can produce off boost anyways. I think lag is a bigger issue with a small 4 cylinder with little torque off idle.

TT stealth and TT supra guys actually ditch their turbos for a single unit when they want to upgrade. Just extra plumbing, complexity and heat that you really don't need. A good quality ballbearing turbo spools very quickly.

But, it is cool to say you have a twin turbo car

now, this is something ive been thinking about for a while. what about stagerring turbo sizes? ya know, a small one for down low, then a larger one for up high? (in the rpms i mean) would it be plausible at all? ya got one turbo thats small, its spools really fast, and maxes out about midway to your max rev limit, then the second turbo spools, and you get power all the way to your redline. it seems that with the revability of the N*, this is plausible but i dont know too much about such things.

what do ya all think, could it work?

btw, sweet motor.

Could it work? sure. But why? A turbo engine if you don't get on it will behave pretty much like a stock engine with the same drivability. When you want to get on it, exhaust gasses spool the turbo. There is no such thing as huge lag anymore. With new turbo technology a properly sized turbo will have very little lag. A stock N* will spin the wheels in 1st and 2nd gear, trust me, you won't even notice lag. Power will be there as soon as you push the gas petal. The only way you might feel the lag is with a 5th gear pull, when you can't break traction and acceleration will be slow until the turbo spools up. Easy way to get around this is to drop a gear so that you are pushing more exhaust gasses through the turbo. Off the line acceleration will still be huge, thats just the nature of the N*.

quote The only way you might feel the lag is with a 5th gear pull, when you can't break traction and acceleration will be slow until the turbo spools up.

That holds true for my car. The only time I have any noticeable lag is when I'm cruising in high gear at low RPM below the boost threshold. If I ease into the throttle there is a noticeable lag as boost builds and a definate kick when it gets there, but if I mash it I get instant acceleration. From a WOT standing start, turbo lag is not an issue.

Rockcrawl, your setup looks awesome. What turbo are you using and what are you using for engine management? Have you taken it to a dyno to have tuned?

I can't even imagine what a N* with a properly sized turbo would feel like.

quote Originally posted by crzyone: Big turbo does equal big lag, but a properly sized turbo means next to no lag. In a fiero, that half second of turbo lag is pretty much a non issue when you have all the torque that the N* can produce off boost anyways. I think lag is a bigger issue with a small 4 cylinder with little torque off idle. TT stealth and TT supra guys actually ditch their turbos for a single unit when they want to upgrade. Just extra plumbing, complexity and heat that you really don't need. A good quality ballbearing turbo spools very quickly. But, it is cool to say you have a twin turbo car

Supras especially want big power for drag racing or dyno drags and don't care about response. When you're worried about response, twins are superior to singles. Think a single BB turbo spools fast? You can use BB turbos in a TT setup as well...

Well, depends on tires as well. I could spin my tires in 1st gear and just hold traction in 2nd with the 3.4dohc. I am running Toyo Proxes 215s all around, atleast until I burn them off with the N*

quote Originally posted by ShaddowGt: now, this is something ive been thinking about for a while. what about stagerring turbo sizes? ya know, a small one for down low, then a larger one for up high? (in the rpms i mean) would it be plausible at all? ya got one turbo thats small, its spools really fast, and maxes out about midway to your max rev limit, then the second turbo spools, and you get power all the way to your redline. it seems that with the revability of the N*, this is plausible but i dont know too much about such things. what do ya all think, could it work? btw, sweet motor.

Looks like the setup a guy had I emailed with...much like in tractor pulling The first smaller turbo helps to spool up the second bigger turbo faster...No idea if the N* would benefit from that.

That's awesome... but it looks like the intake inlets are pointing directly at the pressurized air tubing. Probably just an illusion, or he has some reclocking to do.

quote Originally posted by crzyone: Well, depends on tires as well. I could spin my tires in 1st gear and just hold traction in 2nd with the 3.4dohc. I am running Toyo Proxes 215s all around, atleast until I burn them off with the N*

With 255 Firehawk SZ50-EP's, Konis, hard bushings and 325# springs it does not break traction in 1st...

I am no turbo expert either but I can see the advantages of a TT setup. And smaller turbos are extremely fast at producing power (spooling up) but what is even more impressive is modern technolegy such as twin scroll tubos such as the factory one on a Mitsusbishi Evo. Put that tech into a large turbo and you get the best of both worlds.
I like the looks of the N* featured here but I do see some possible issues with the design. The first turbo feeds directly into a T fitting while the second one is on a 180* elbow. I would think that this would cause great turbulence due to T1 pushing the air into a dead end at the T and the force would direct the air in both directions. T2 is pushing the air past thi turbulent air which is now causing a rolling effect. This is going to cause resistence and will not be as efficient as a single turbo would be. Don't get me wrong here, I think that is gonna be one BAD AZZ Fiero but