.48 vs. .63 a/r lag and power

[Mike 99GSX]

I get 20 pounds at 3600 RPM on pump gas. Thats with the 264/272 cams, VPC/GCC.

 

[MaineDSM]

Originally posted by JayHass


FYI I gained *80* whp going from a .63 housing to a .82 housing with a 76 trim stage-III turbine wheel and a 50 trim T04E compressor in a .50 housing. Same boost, same dyno, same tune.

Jay, you have a lot of experience, and I always enjoyed reading your insights and stories back when you had the Nissan.

But please, will you SHUT THE HELL up about your experiences with that car and it's turbos and trying to compare them with the DSM experience? I guess it wouldn't be so bad if you weren't so cocky and self-assured about it.... but you are, and it's getting annoying.

The cold, hard facts are this: DSM'ers run 11s and put down 400whp with .48 A/R exhaust housing. They get great spool times. This makes them happy. Some people don't care about spool and lag, and want more top end... they go with the bigger A/R housings.

Please stop treating people who like .48 A/R housings like stupid morons. Maybe 4000rpm is too much lag for them. And don't give me the crap about "manifold backpressure", I have not seen that hurt a car yet.

Try to base your posts on experience with your DSM. Your glory days with the Nissan are gone... just let it go man, let it go.

 

[JayHass]

Originally posted by MaineDSM
But please, will you SHUT THE HELL up about your experiences with that car and it's turbos and trying to compare them with the DSM experience?

First off, do I know you? Have we ever met? I don't think I have heard of you before so I don't know how you can know me so well.

Secondly Please do a search and find just how much I am referencing that car. You might find it wasn't much. In fact that post is 3 months old and you probably can't find another post about the car since then.

If you like I can compare apples to oranges and talk about my turbo RX-7, or the countless domestics I've built.

My bad for talking about another 2.0 liter 16v motor with the same VE as the 4G63.

Turbo engineering is turbo engineering. What car it's on doesn't make a difference. It is what it is. 2+2=4.

I guess it wouldn't be so bad if you weren't so cocky and self-assured about it.... but you are, and it's getting annoying.

Oh, I didn't realize you can get that all from a bunch of typed words on a board. Perhaps I was just shocked we got 80whp from a turbine change. Has the ever occured to you? Because that is what the emphasis was for. We were shocked.

Whatever man, you can think whatever you like but you're wrong.

The cold, hard facts are this: DSM'ers run 11s and put down 400whp with .48 A/R exhaust housing.

And the cold hard facts are that a .48 housing is too small. (Unless you SERIOUSLY open them up but what's the point then, just get a larger housing) I never said it wouldn't make power I said it makes the wrong kind of power. You are arguing with a Garrett engineer that forgot more than all of this forum combined. I am not only quoting my experience but his knowledge as well.

I can make 500hp with a basically stock Mustang and 250hp shot of juice. Is that the right way to do it? Nope. Do people do it? Yup.

Please stop treating people who like .48 A/R housings like stupid morons. Maybe 4000rpm is too much lag for them. ,

Who ever said they were stupid? When did I EVER get on the people who own them?

And don't give me the crap about "manifold backpressure" I have not seen that hurt a car yet.

Yes because up in Maine there are countless DSM's with big turbo's for you to compare with.

So are you saying that detonation doesn't hurt a car? How about a popped head gasket?

Those are just two things that stem from a choked turbine and a negative deltaP in the exhaust manifold because of something called reversion. That's when you have more pressure in your exhaust manifold than your intake manifold.

Ever take a backpressure reading at the manifold and see what happens when a turbine chokes? Ever see a bench test from Garrett documenting the same thing? I have.

I suggest you do some research before you come out on a board and try to stick me out hard core like you did. I've provided safe sound advice in this thread. What have you contributed?

Try to base your posts on experience with your DSM.

Mine and the several I've built or help build ARE the basis of 95% of my posts on this forum. BUT when the need arises for me to use the Nissan for reference I will. Deal with it.

 

[MaineDSM]

Originally posted by JayHass

And the cold hard facts are that a .48 housing is too small. (Unless you SERIOUSLY open them up but what's the point then, just get a larger housing) I never said it wouldn't make power I said it makes the wrong kind of power. You are arguing with a Garrett engineer that forgot more than all of this forum combined. I am not only quoting my experience but his knowledge as well.

Ah yes. The famous "Garrett engineer". The fact that you take this guys word over people's actual experience says it all.

I have a strong feeling we could line up two identical cars, one with a proven DSM turbo, and one that should be better according to Mr. "Garrett Engineer". The proven turbo could tear the engineer's turbo a new asshole, and you would say their was something wrong with the car.

The .48 A/R Housing WORKS for many DSM'ers. Sure, they might get more power from a bigger housing, but they don't want the lag. Get over it.

 

[Jason's TSI]

I can tell you from personal experience that the .48 A/R housing did not work for me, but I am looking for HP not quick spool. If you hate turbo lag, go NA you will have none of that pesky lag. Personally I want to beat the guy I am racing so I have an .82 A/R.

 

[BlitzMR2]

For a little perspective here, I drive a MR2T. Being mid-engined, power accessibility is a big issue. Controlling the balance of the car in and out of corners, having torque available to correct your line in turn, not having a mallet-like turbo come on and hit mid-sweeper and upset your delicate balance, etc, are all important in any car, but are especially critical in a mid-engined car. I still want a huge top-end rush or I'd have stuck with the stock turbo, so it's up to everyone to find the compromise they like. It CAN'T all be simply about HP or we'd drive V8s; there is also character, flexibility and power delivery, peak HP, predictability, racing venue, etc to consider.

How about building a well-rounded, devistatingly fast, agile and capable sports car, able to run an autocross, road course, or 12.2s all day at the strip. That's the whole point, IMHO, about many of the athletic JDM cars, so choosing an .82 doesn't always make sense. Some may be able to drive fast in spite of an .82 on a road course, but is it optimal? Different strokes....

 

[JayHass]

Originally posted by BlitzMR2
For a little perspective here, I drive a MR2T. Being mid-engined, power accessibility is a big issue. Controlling the balance of the car in and out of corners, having torque available to correct your line in turn, not having a mallet-like turbo come on and hit mid-sweeper and upset your delicate balance, etc, are all important in any car, but are especially critical in a mid-engined car. I still want a huge top-end rush or I'd have stuck with the stock turbo, so it's up to everyone to find the compromise they like. It CAN'T all be simply about HP or we'd drive V8s; there is also character, flexibility and power delivery, peak HP, predictability, racing venue, etc to consider.

How about building a well-rounded, devistatingly fast, agile and capable sports car, able to run an autocross, road course, or 12.2s all day at the strip. That's the whole point, IMHO, about many of the athletic JDM cars, so choosing an .82 doesn't always make sense. Some may be able to drive fast in spite of an .82 on a road course, but is it optimal? Different strokes....

Actually I agree with what you said 100% but you have the characteristics of the housing backwards I think.

The .82 is actually one of the smoothest regarding boost onset when used on a 2.0 16V motor. It's the small housings that "spike" and come on like a mallet.

Ah yes. The famous "Garrett engineer". The fact that you take this guys word over people's actual experience says it all.

I have a strong feeling we could line up two identical cars, one with a proven DSM turbo, and one that should be better according to Mr. "Garrett Engineer". The proven turbo could tear the engineer's turbo a new asshole, and you would say their was something wrong with the car.

Nice try but the fact that he HAS engineering turbo's for people who built 500+whp cars says a lot. His turbo designs make power and run the number.

Did I mention the fact that NONE of these cars he had a hand in have ever blown up? Not one.

He is an OEM supplier, he engineers systems with an OEM reliability mindset.

You can make fun of whatever, it doesn't matter all it shows is your ignorance of anything other than "so and so's car runs 10's, does your car run 10's". His turbo's make the power and keep the cars stone reliable. You can't argue with that.

I still challenge you to provide some techincal information to back up what you say, you havn't up till now other than "so and so's car runs 10's, does your car run 10's?" and moreover you havn't even provided a person making what you claimed. No examples, no proof, no knowledge. It's all hearsay at this point and a poor attempt to attack me for no reason.

 

[BlitzMR2]

Originally posted by JayHass


Actually I agree with what you said 100% but you have the characteristics of the housing backwards I think.

The .82 is actually one of the smoothest regarding boost onset when used on a 2.0 16V motor. It's the small housings that "spike" and come on like a mallet.

The smaller housings have more "on call" power than the bigger housings do. Downshifts are not an option mid-sweeper at 45 MPH, and if you're in 2nd for a tight right hander, you're surely not going down into FIRST for more line-altering power, that's too much going on when things are happening very fast, and very hard on your tranny. The smaller housings do come on fast in a "spiking" kind of way, but the power is very linear and tractable -the 48 I drove had a stage 5 wheel and never ran out of power, even on stock cams. I have driven 48s and 63s, and IMHO the 63 hit much harder. My old 20G hit harder than the 48 as well, which is the only downside I felt it had. It was great for going in a straight line, but in pursuit of HP one can often cripple the overall dynamics of their car.

I wish I could have 2 turbos -a 82 for straight line, and a 48 for everything else. FWIW, we have stock turbo'd MR2s in the 11s, so HP and small turbos aren't necssarily mutually exclusive, but small turbos do suck

 

[JayHass]

Originally posted by BlitzMR2


The smaller housings have more "on call" power than the bigger housings do. Downshifts are not an option mid-sweeper at 45 MPH, and if you're in 2nd for a tight right hander, you're surely not going down into FIRST for more line-altering power,

I guess this is where we disagree, and maybe it's because we road raced two different types of cars.

For me in a FWD car, the .82 between say 3000-4000rpm would build 12psi max but come on in a non violent way. Over 4000rpm, it was pretty much how much do you want and when.

Granted I had a ported, extrude honed, thermal coated, ball bearing,.82 housing with a Stage-III wheel and 50trim T04E.

All that helped make the turbo super smooth and super responsive to throttle input.

I drove had a stage 5 wheel

There it is, that's the differnece.

There are two ways to add top end and flow to a turbine housing. Wheel, housing or both.

What I have learned is it's better to go with the larger housing until you max the wheel out instead of stuffing a big wheel in a small housing. It makes for a more efficient turbo. At least this is what I learned from reading a turbine map and bench test that came right out of Garrett's lab.

FWIW, we have stock turbo'd MR2s in the 11s, so HP and small turbos aren't necssarily mutually exclusive, but small turbos do suck

Oh I agree, and I've never once said that small(ish) turbo's CAN'T make the power, just that the proper way to engineer a turbocharger is to not stuff a huge wheel in a small housing. Will it work? Most likely, it's just IMHO not the right way to do it and can cause other problems.

 

[BlitzMR2]

You do lose efficiency in stuffing a big wheel in a small housing, but what you lose is extremely small, and a perfect compromise for those not wanting to move in housing size, but needing more flow than a Stage 3 wheel can deliver. I am speaking about T3/T4 hybrid turbos though, not big wheels in stock turbo housings. I just say no to stock turbos

In talking to ITS, they weren't very concerned about the very small loss in efficiency, and liked the turbo very much for a 2.0 engine -of course that is a very vague "thumbs up".

You mention 12 psi by "3000-4000" -on a local MR2T, untuned, we were hitting 15 psi at 4500, and nothing was happening below 4k -certainly no amount of power capable of adjusting the car or keeping the rear toed-in and hunkered down around corners -again, this could be and I think IS indicative of the differences between our cars, mid-engined RWD versus AWD or FWD, so it may not be worth discussing.

I bought a dual Ball Bearing T04E-50, .48 turbine with a Stage 5 inconel wheel Should be sweet. If it sucks, I'll go to a 63, but will leave the 82 to you DSM studs

 

[MaineDSM]

Originally posted by BlitzMR2

I bought a dual Ball Bearing T04E-50, .48 turbine with a Stage 5 inconel wheel Should be sweet. If it sucks, I'll go to a 63, but will leave the 82 to you DSM studs

Stage 5 turbine wheel? How much of a diff. is that from a Stage 3?

Us 2G guys are the only DSM Studs. Women actually *run away* from the 1Gs. This is fact.

 

[Ed98GST]

This thread is a great discussion -- pros, cons, different experiences, and an overall wealth of information on 50 trim combos (which happens to be the setup I'm pursuing). Thank you and keep it up! I haven't found many tuners around my area who have "major" setups that I can witness, so I have to rely on experiences of others (like this board).

*Soapbox on*
Disagreement and dissention are fine (they even promote better discussion), but please keep character attacks out of this (MaineDSM), as they only detract from the thread's purpose. Also, facts and experience are great, but recklessly whoring up a thread with "I'll bet if someone did this" doesn't serve any purpose other than to make someone like me (who is trying to learn from others' experiences) sift through useless bullsh*t.
I think some people are missing the point. This discussion isn't simply about what works, but rather what works potentially better. If you disagree with the discussion and think that x is better than y, present some flow bench numbers, logs of injector duty cycle, timing, a/f ratios, etc. etc. to prove your point. Also include any personal experiences with both products for a FACTUAL discussion WITHOUT attacks on a person.
*Soapbox off*

Wanted to say thank you for the great info and discussion, but sorry for the rants. I normally keep quiet and generally don't post much b/c I'm always at work, but I love to learn about DSMs and turbos in general and don't like to see this happen. Looks like I've whored up the thread as well...sorry.

 

[BlitzMR2]

Originally posted by MaineDSM


Stage 5 turbine wheel? How much of a diff. is that from a Stage 3?

Us 2G guys are the only DSM Studs. Women actually *run away* from the 1Gs. This is fact.

I'm not sure exactly, measurement-wise, how much physically bigger it is, only in general that it flows more than a Stage 3 Call ITS and see what they say 805-526-5400