cheap turbo upgrade

[mattb3562]

I will let you all know in a couple months if this as good idea as I believe it will be. The stock t3 on my l28et was missing some parts, so I needed to come up with one for my turbo swap into a 76. My buddy had a Garrett a/r60 m11 that came off an 88 SVO that I got for free. It has .60 trim on compressor side and .48 on the exaust, so I used my .63 exaust housing with internal wastegate from stock turbo. The m11 has an oil/water cooled center, so it should last a while on a timer. I know it's not gonna make huge power over stock, but if it spools as well as I think it will, I think it will be a good cheap option for all of us wanting about 275 whp. That's what I'm shooting for at 14-15psi. I know that it will not have the capability of the common t4 upgrade, but like most here, on a working man budget, you can see the compressor size difference and these Garrett's can commonly be found around $150. And I think it will last alot longer than an ebay special. I will post progress when I get it all put together.

[skirkland1980]

So the turbine wheels are the same size?

[letitsnow]

A stock T3 will make 270rwhp.

 

[Six_Shooter]

I used the Ford 2.3 Turbo on one of my old V6 builds, a 3.2L. It made 250HP (dyno), though it may have been a little fuel limited, this did seem to be the limit of these turbos air flow wise. I felt that it was a bit small for my application, but thought it might work well on an engine less than 2.8L.

[Xnke]

You just put the stock turbo right back on...with a water cooled center housing. Not a bad idea, the water cooling should help with oil temperature control, but as far as the compressor goes...

 

There was no upgrade there.

 

Yes, the compressor housing looks bigger on the outside...it is...but most all of the information I have on the stock Nissan T3 is that it's a 60 trim T3 compressor.

[Snailed]

I will let you all know in a couple months if this as good idea as I believe it will be. The stock t3 on my l28et was missing some parts, so I needed to come up with one for my turbo swap into a 76. My buddy had a Garrett a/r60 m11 that came off an 88 SVO that I got for free. It has .60 trim on compressor side and .48 on the exaust, so I used my .63 exaust housing with internal wastegate from stock turbo. The m11 has an oil/water cooled center, so it should last a while on a timer. I know it's not gonna make huge power over stock, but if it spools as well as I think it will, I think it will be a good cheap option for all of us wanting about 275 whp. That's what I'm shooting for at 14-15psi. I know that it will not have the capability of the common t4 upgrade, but like most here, on a working man budget, you can see the compressor size difference and these Garrett's can commonly be found around $150. And I think it will last alot longer than an ebay special. I will post progress when I get it all put together.

 The wheel size is not printed anywhere on your turbos.  People just lazily refer to turbos by whatever it says on the cover (a/r) but it has nothing to do with what actually matters when you are trying to replace or upgrade a turbo. Don't trust what people say about a used turbo. Measure it.

 

The trim of the compressor or turbine wheel is a relationship between it's inducer and exducer measurements. Measure the wheel dimensions on your new one and see what you have in comparison to the old turbo. The A/R printed on the housings is not related to what wheel in inside and has little to do with how much power it can make. You need to measure the wheels directly to figure out what they are. There are all kinds of turbo wheel charts available with a little searching.

[Tony D]

Personally, I would have retained the smaller Ford A/R housing.

I didn't know they had a .48 hot side, I'm kicking myself now for not snagging them from the JY throughout the years.

 

Makes for a nicely increased bottom-end spool. 15~16 psi is available from that combination at 1,700 rpm going WOT and clutch dropping from idle. More like typical supercharged response than typical turbo-supercharged response.

 

What you lose on "ultimate power" really is augmented by hellacious torque from 1,500 on to the can-limited 5,500 rpms.

 

I would say mating that 0.48 hot side to an improved compressor section and a hot Isky Cam designed for flow to 6,500 rpms would reap impressive driveability and power under the curve!

 

Hope you didn't toss that 0.48 A/R housing! (FYI, JeffP tested his 0.63 A/R on the 500RWHP build, and found exhaust backpressure identical to intake pressure at 7,000 rpms during full-load testing, so the myth of the .63 A/R housing "restricting the top end" is just that: a myth!)

Edited February 18, 2013 by Tony D

[mattb3562]

I really wanted to run that .48 turbine, but the 5 bolt pattern on it doesnt match up to my internal wastegate housing. If u believe it to be that beneficial, Tony, would I be better off to find another wastegate housing and run the .48 or is it that much difference? Also, I have the n/a cam out of my 76 and read that was good for another 500 rpm on the curve. Would this be a good route to take? Overall numbers are not my main goal as is at least a 12.9 quarter time.

[Snailed]

So even if it's a smaller compressor wheel you are concerned with fine tuning the turbine housing? Backwards.

[Snailed]

 (FYI, JeffP tested his 0.63 A/R on the 500RWHP build, and found exhaust backpressure identical to intake pressure at 7,000 rpms during full-load testing, so the myth of the .63 A/R housing "restricting the top end" is just that: a myth!)

Tony, I like your personality and drive to share but you post is packed with misinformation.

 

A .63 a/r turbine housing that fits a standard t3 turbine wheel (like all OE fitted T3s have and what the original poster is talking about) is not even close in restriction, power, size, anything, to a .63 a/r housing that fits a large aftermarket turbine wheel like a T31(stg3) or t350(stg5). It's just not relevant what the turbine a/r of a 500+hp turbo is in relation to a stock T3 from a Ford, Saab, Nissan, etc...

 

And beyond that, when the system is at full boost you are not measuring the restriction of the turbine wheel and housing combination since most of the exhaust is going out the completely OPEN wastegate.

 

A/R is a teeny tiny fine tuning thing compared to wheel size and is not comparable in any way if the wheels are different. Your turbo size is never printed on the outside of it. You need to know the what wheels are in the turbo(s) to have an intelligent conversation comparing turbos even though a lot of people think the stampings on the covers are comparable and insist on referring to those numbers as "trim" as if they have anything to do with how much air it can flow.

 

This is the same lazy information processing that leads people to think the aspect ratio number on a tire is comparable without knowing the width of the tire. [dumbass voice] "Hey is says 60 right here and that's bigger than 50 so it must be a taller sidewall!" when one tire is a 205 and the other a 295.

[BLOZ UP]

I've always wanted to see a large, low pressure turbine with a hot cam make lots of power. Do the turbo 2jz people do that?

[letitsnow]

I went 12.6, after that dyno I posted above, on nearly corded street tires, If I hooked up the 2 step and bolted some drag radials on, I'm pretty confident I could have gone ~12.0-12.3. I wasn't having traction issues, but the launch on that run was almost .1 off my best that night(1.79 vs 1.87), but it was my best shifting. I was launching at 5k or so with no boost and slipping the clutch just slightly.

 

If I hadn't found a deal on my HY35, I probably would have picked up a T3/T4 with a 50 trim compressor wheel, a stage 3 turbine, and a .48 turbine housing. I think that setup would be able to make ~400ish rwhp with killer response and torque.

[mattb3562]

Ok u got me, i dont know everything about turbos. Lol But i do appreciate all of ur responses, its all very informative. I did believe that the larger compressor would flow better than the nissan unit, but am I wrong? Standard t3 wheel size on both sides. I have the .63 hot side on it now, but i can come up the wastegate for the .48, if it will be that beneficial. Like i said, i'm not shooting for huge numbers, just a 12 second street car. I do love the idea of more low end and quicker spool, but I didnt know if it would outweigh the small amount of extra heat. ( however, it will be intercooled) What started out with a good idea has now turned into something more...what would you all do without spending any more large amounts of money? Btw, snow, how much boost were you running on your 12.6 pass?

[letitsnow]

It was running up to 18psi in the midrange with a linear taper down to ~10psi by redline. If you look at my torque curve, that's almost exactly what the MAP trace looked like, just offset about 500-700rpm to the right.

Edited February 19, 2013 by letitsnow

[Snailed]

Ok u got me, i dont know everything about turbos. Lol But i do appreciate all of ur responses, its all very informative. I did believe that the larger compressor would flow better than the nissan unit, but am I wrong? Standard t3 wheel size on both sides. I have the .63 hot side on it now, but i can come up the wastegate for the .48, if it will be that beneficial. Like i said, i'm not shooting for huge numbers, just a 12 second street car. I do love the idea of more low end and quicker spool, but I didnt know if it would outweigh the small amount of extra heat. ( however, it will be intercooled) What started out with a good idea has now turned into something more...what would you all do without spending any more large amounts of money? Btw, snow, how much boost were you running on your 12.6 pass?

 

I don't know everything about them either. The sizing stuff is very basic and information you need to have if you want to swap around used turbo parts. I have taken more than my share of junkyard turbos out, rebuilt and reused them in custom turbo kits on other engines. I learned a lot taking them apart but I also realize how much I don't know.

 

Here is a chart of Garrett turbo wheel sizes. Take off the compressor covers and measure the wheels. Bigger is better in this case. There are several compressor wheels that are fitted to OEM T3s. I would use the .63 turbine housing. On such a large engine, the difference in spool between the .48 and .63 will be negligible.

[Tony D]

I'm not getting into the re machining of the STOCK housing to accommodate aftermarket wheels, but the post was mostly to stick a pin in the C Bell contention that exhaust backpressure is much higher than intake manifold pressure which is why "you don't want to port the intake or run a cam due to reversion"...

 

But then again, this guy WASN'T talking about a huge aftermarket turbine wheel was he? The difference between a .48 and .63A/R on a stock engine is quite profound.

 

Try to get 16-17psi boost on a stock .63 A/R hot side and compressor wheel before 2,000 rpms without MASSIVE timing retard!

 

This was the context of the discussion.

 

If you want to parse the actual technical bits of JeffP's test, no I'm sorry your assumption is incorrect. Boost came on at 3200, and with the waste gate held closed to watch intake -vs- exhaust pressure the exhaust backpressure never significantly exceeded the intake charge pressure, right up to 7,000 rpms. Dumping pressure overboard on the intake compensated for the non-linear flow. Could we use more of the boost, would that result in higher backpressure? From what we saw, yes maybe, but not in the 4:1 ratios suggested by some "authorities" who are quoted as definitive sources on Turbocharging.

 

Yes, with a set of staged waste gates you can dump all sorts of flow around the turbine to prevent backpressure and allow very small wheels to get earlier boost... But that isn't what's being talked about. The overboard internal waste gate on the stock turbine was easily enough wired shut.

 

We were at no time anywhere near even a 2:1 ratio!

 

Turbo Hotside and old side compressor technology has progressed immensely in even the past ten years much less the last 20!

Edited February 20, 2013 by Tony D

[Snailed]

Ok, the back pressure was tested correctly where I assumed it wasn't. The setup described still sounds unlikely and not applicable to the goals of the OP to me.  What is this compressor wheel that can flow 55-60lbs/min happily with a stock T3 on the other end? I suspect there is a reason beyond sheer ignorance a stock T3 turbine is typically abandoned after 275-300 hp.

[Tony D]

Agreed, but with re-machining a quite advanced hybrid can be made utilising the stock housing.

 

The test was also a beta for a boost control system that controls the compressor end separately from the turbine end. I. The end we decided to shelve the idea as we neither had the time to develop it, but the idea revolved around controlling wheel speed to as close as constant as possible, and control waste gate to that end, whilst using overboard ump to keep pressure in the appropriate highest efficiency map (which self-shifted to follow different speed maps for the compressor wheel.

 

It was an incidental discovery. It was not what we were actually looking or, but it shocked us when it was revealed.

 

With a bigger wheel in there, backpressure upstream is quite a bit lower than the paradigm in all the books... Meaning cams can actually be a bit more aggressive than previously thought.

[mattb3562]

Again, I appreciate all of the response, as this has been a very informative conversation. My 275 whp goal was not as important as being in a 12 sec bracket. ( plenty fast for a driver, IMO) The issan turbo i have had no wheels to measure, but according the wheel chart posted, all t3. 60 trim compressors will have the same wheel size. Difference in size, being in different trim. Ergo, if you can find the specs by part number or however on a factory turbo, assuming it hasnt been monkeyed with, you should be able to tell wheel size. According to this chart anyway. But yes, the turbine wheel from the. 48 ford housing fit perfectly without modification in the. 63 nissan housing. With all of that being said, I am still convinced that this larger compressor with the same wheel size will flow better than the nissan unit. I love your idea, Tony, about the quicker spool and more bottom end making for a more responsize street car. Think I'm gonna go that route and after some research, I'm gonna go ahead and throw in my n/a cam out of my 76. I'm gonna trow out the concern on overall hp at this point. But again, thanks, fellas.

[Xnke]

The Ford T3 is the SAME COMPRESSOR WHEEL IN THE SAME HOUSING. It's not any bigger. There was no upgrade there. The .48 A/R housing would do exactly what Tony said, bring in the boost sooner...but it would behave identically to the Nissan turbo with the same .48 A/R housing.

 

Every functional turbocharger has wheels to measure...we're talking about the moving parts! If your Nissan turbo didn't have wheels to measure, it was a center housing, turbine housing and a compressor housing with no moving parts...