I've gone Festarded (BP+T build): pile-O-parts is almost complete!

[zoom zoom]

^

Kinda why I went with the smaller(ish) gt2554r, I'm hoping that gasket matching the intake and exhaust and doing the cut intake mod on the vics manifold will flow better which is more(or same) power on less boost.


Well kinda...I mean who's gonna pass up a 1000$ turbo for 350$? It was the one I was eyeballing when window shopping tho, the pieces just kinda fell into place..

[DON SVO]

Well you can't run a turbo and not have a certain boost setting, so it was a relevant question at least

It is in terms of tuning, sure. I'm hoping to hit the power numbers I want with less than 15PSI, if that makes sense. For the setup I'm trying to be slightly over compressored. I don't think I'll flirt with surge limit but I'd rather not have to spin it's brains out either.

[Damkid]

It is in terms of tuning, sure. I'm hoping to hit the power numbers I want with less than 15PSI, if that makes sense. For the setup I'm trying to be slightly over compressored. I don't think I'll flirt with surge limit but I'd rather not have to spin it's brains out either.

Yes that does make sense, everything you stated does make sense to me but most people don't think about the work put into a project to help with flow/volumetric efficiency etc. when they ask the basic questions of a turbo setup

[DON SVO]

Yes that does make sense, everything you stated does make sense to me but most people don't think about the work put into a project to help with flow/volumetric efficiency etc. when they ask the basic questions of a turbo setup

I know

Enough resistance to produce 200/200 to the tire

<---- anti "How Much Boost You Making?" Guy

[Advancedynamix]

^

Kinda why I went with the smaller(ish) gt2554r, I'm hoping that gasket matching the intake and exhaust and doing the cut intake mod on the vics manifold will flow better which is more(or same) power on less boost.


Well kinda...I mean who's gonna pass up a 1000$ turbo for 350$? It was the one I was eyeballing when window shopping tho, the pieces just kinda fell into place..

gt2554R is a great little turbo! Have one on my nightstand, it was going to be used on tweak, but I have another trick up my sleeve . It will be a very easy turbo to drive with a 1.6 or 1.8 and would make a gnarly B3. It's awesome that you got it for $350, retail is closer to the tune of $1200.

[DON SVO]

Ugh. Busy day.

Swapped the springs around on the coil overs to improve the ride quality. I ordered 2 125# Black Magic 2 9/16 x 10 coil overs and put them out back with the helper spring still in place. I tend to be a bit of a cheapass, plus the BP+turbo setup adds a good deal of frontal weight, so I took the Race Land rear springs and put them up front without the helper spring.

ANYONE... I repeat ANYONE... who has the Race Land/Rokkor set up with the supplied springs needs to do this. The ride quality is VASTLY improved, turning has a LOT less oversteer and it handles ben better since *gasp* the springs actually compress so the suspension can do it's job, LOL!

2 springs + my labor = $80 WELL spent.

Lastly I did the pink/green/pink fusible link conversion.

Should be installing the G25MR transmission next weekend.

[91mcnasty]

Yes that does make sense, everything you stated does make sense to me but most people don't think about the work put into a project to help with flow/volumetric efficiency etc. when they ask the basic questions of a turbo setup

I've got to start somewhere, just like everyone here did. I asked boost level because I thought the turbo was a little Over-sized(inexperience) and thought your power goals would be obtainable with 7-10 psi. Trying to develop an understanding of alot of things at once, with my own turbo build in progress Im already behind you guys that have it all figured out.

[DON SVO]

I've got to start somewhere, just like everyone here did. I asked boost level because I thought the turbo was a little Over-sized(inexperience) and thought your power goals would be obtainable with 7-10 psi. Trying to develop an understanding of alot of things at once, with my own turbo build in progress Im already behind you guys that have it all figured out.

Please, don't take what I said as an insult. I'd never bag on anyone for asking a question. I ask a ton of them myself! I learned how to read compressor maps years ago thanks to asking very informed and intelligent people tons of questions (how much boost are you making? )! If you don't ask you'll never learn. I firmly believe that the dumbest questions are the ones that are never asked... If you don't know, you're not going to learn unless you stick your neck out and inquire.

I have seen a lot of people build projects around the turbocharger itself, and HOPE to make XXX horsepower. I guess a realistic way to look at it is the old school single turbo Supras: once people found out the 2JZ GTE could handle gobs of power, they threw the biggest singles that they could bolt onto the things and made these insane vertical dyno graphs that were obscene in total HP, but absolutely useless for anything except highway runs.

I chose the T3 from the turbocoupe because I'm extremely familiar with how they operate. Their efficiency zone should be good from 4,000-6,500 rpm on the slightly smaller BP, however the DOHC BP motor succeeds in producing more airflow at lower RPM levels than the 2.3L motor the turbo came from. I imagine that I'll be pulling back timing and fattening up the fuel delivery in the 3,000-4,500 rpm range... this should feasibly bring in some lower RPM torque and making the car very safe to drive aggressively in day-to-day activity. Most turbo cars blow up due to lean situations at or near peak torque (pre-detonating and snapping rods/rod bolts/wrist pins etc), so a safe fatty mid range will help the car survive longer, produce more torque early on and provide easy near-instant spool after 3,000rpm.

With the T3 flanged manifold, I'll have a lot of room for growth. There's a billion hybrid turbo choices I can use later on!

[91mcnasty]

I figured you were getting annoyed since you said it was irrelevant twice, didn't take offense. Believe me I'll never quit askng those dumb questions, im a curious fellow haha. I also Plan to use a t3 flanged turbo because of availability. Not quite sure how I'll adapt the t3 to the bp26 mani, think I remember seeing adapters on cp.com but I'll see what I can do with it first. Your great at explaining things, unfortunately I've never had compressor maps explained to me but I can read and I can find some google time.

[zoom zoom]

I figured you were getting annoyed since you said it was irrelevant twice, didn't take offense. Believe me I'll never quit askng those dumb questions, im a curious fellow haha. I also Plan to use a t3 flanged turbo because of availability. Not quite sure how I'll adapt the t3 to the bp26 mani, think I remember seeing adapters on cp.com but I'll see what I can do with it first. Your great at explaining things, unfortunately I've never had compressor maps explained to me but I can read and I can find some google time.

Buy Corky Bells Maximum Boost bro.. seriously.

[DON SVO]

Buy Corky Bells Maximum Boost bro.. seriously.

Good choice!

I figured you were getting annoyed since you said it was irrelevant twice, didn't take offense. Believe me I'll never quit askng those dumb questions, im a curious fellow haha. I also Plan to use a t3 flanged turbo because of availability. Not quite sure how I'll adapt the t3 to the bp26 mani, think I remember seeing adapters on cp.com but I'll see what I can do with it first. Your great at explaining things, unfortunately I've never had compressor maps explained to me but I can read and I can find some google time.

Just remember that boost is a measure of resistance compressor maps are invaluable because, in a very well sorted combo, you can have a reasonably appropriate turbocharger completely maxed-out and not even making over 15-16psi. We had a guy do a Volvo head swap/3" exhaust and a decent-sized ebay bar/plate FMIC on our SVO board using the stock T3, he had maxed the VAM and injectors at 14PSI of boost and had 12:1 on his LM-1... A dyno verified he was making 260 to the tire.

We are going to cut the BP26 IHI flange off at about a 5* angle and weld on a T3 flange.

[DON SVO]

I'm feeling somewhat nice today, I'll break down a compressor map for you. This is pretty simplified, I don't wanna blow your mind with VE calculations and PSIG/PSIA conversions

Here is a Super 60:



Now, air pressure is 14.7. That is real time pressure, or 1 BAR (hence MAP sensors reading in BAR). The graph starts at 1.00 on the left side and increases from there. 14 PSI of boost? Just a tick under 2 BAR.

The bottom numbers are lb/min of airflow. This is where your engines Volumetric Efficiency and CFM numbers from your cylinder head become very useful when building a specific combo. For us, just realize that every lb/min is roughly 10 flywheel horsepower.

The oblong ovals are the areas of efficiency in this turbo. Bullseye represents where the turbo is best. Going to the left we find the surge line, going to the right we find the compressors overspin zone. We want to make sure that we operate in the center during normal driving and don't have a lazy, laggy turbo or one that's too small and is not efficient when the engine makes power (lb/min)

The following example is using the Super 60 but made-up numbers...

Now, if it's too small of a turbo... let's say I nail the accelerator and the engine is trying to suck up 40 lb/min and spikes up to only 10PSI of boost (the engine is that efficient), we've worn out our welcome and that turbo is going to over spin and be nothing but a hairdryer on the super hot setting. Now let's say it's too big, and I nail the accelerator at 1,600 RPM... My engine is only able to consume 8 lb/min but spikes boost up to 14. The compressor surges because the engine can't eat what it's being fed and basically backs up the inlet tract... This is a surge or stall. We don't want that either!

Now, what we want to do is see if our goal (225 flywheel horsepower) can be achieved with this turbocharger. 23 lb/min should be roughly 200 to the tire. I should be able to do this comfortably with 13-15psi (1.85-2.10 BAR) and produce enough airflow to avoid a surge situation. Dyno graphs of N/A BP cars show me that I'll produce enough torque at lower RPM to avoid surge. Follow a line up from 23 lb/min and then follow a line from the left @ 2.00... Son, we're right in the wheelhouse of turbo nirvana !!!!

[DON SVO]

Definitely sits and rides better.

[91mcnasty]

Seriously huge thanks don. And trust me I'm not turbo retarded been wrenching on wrx's and sti's for awhile and also repair our 3 turbo diesel tow trucks. I'm trying to transform myself from a parts changer to A great diagnoser, i hate feeling helpless so I must learn EVERYTHING haha!!!

[DON SVO]

Seriously huge thanks don. And trust me I'm not turbo retarded been wrenching on wrx's and sti's for awhile and also repair our 3 turbo diesel tow trucks. I'm trying to transform myself from a parts changer to A great diagnoser, i hate feeling helpless so I must learn EVERYTHING haha!!!

I LOVE planning. Compressor maps can help so much. Properly reading a compressor map isn't super easy. A Lot of folks are just, "30 lb/min = 300hp? I can do that!" and buy an over-sized turbocharger that they can BARELY use. Or, they get recommended something cheap and say "that'll work! 250hp is what I want!" but their engine has horrendous flow #s (intake/head/header/etc) and proceed to wonder why theyre making 230 to the tire @ 22psi and blowing head gaskets.

I plan to blow my motor up the old-fashioned way: torque bending the rods until I create a see-thru BP block!