35r or 60-1 for pump gas?

[Maglin]

It still amazes me why people that want to push 600+HP will ask something like this and everyone get their panties in a bunch over it. Seriously if you are looking to push that kind of power you already should know what you are doing and realize the crap behind marketing and popular demand. If you don't it's ok, but these arguments just lead to the same conclusion as in the beginning. It's whatever you think you want to run on your car. People wanting to push 600+ that don't understand this stuff should leave it to their mechanic or do a lot of reading. DSM-onster has his facts straight. I don't agree 100% but most of what he says is pretty good info. Dude run what makes you feel happy or what makes your friends happy. If you have money to spend on a 35R then buy it and be done with it.

 

[Slippi84]

It still amazes me why people that want to push 600+HP will ask something like this and everyone get their panties in a bunch over it. Seriously if you are looking to push that kind of power you already should know what you are doing and realize the crap behind marketing and popular demand. If you don't it's ok, but these arguments just lead to the same conclusion as in the beginning. It's whatever you think you want to run on your car. People wanting to push 600+ that don't understand this stuff should leave it to their mechanic or do a lot of reading. DSM-onster has his facts straight. I don't agree 100% but most of what he says is pretty good info. Dude run what makes you feel happy or what makes your friends happy. If you have money to spend on a 35R then buy it and be done with it.

YUP!

Only problem is people take that too far and start acting like asswholes to each other going "why don't you search first" I would rather let the OP see diffrent point of view and options then be told to go look for himself.

 

[dsm-onster]

Slippi84, I hope you realize that where you see the 30R taper off is right at where it's compressor chokes; around 550 hp. Of course the 35R compressor still pushes more. It simply has a compressor wheel that will supply more demanded flow. Where in that dynograph do you see compressor efficiency have such a drastic effect before choke. What is altering overall flow thus horsepower at the point both wheels taper off?

I hope you also realize that I'm only discussing a 75% efficient intercooler when discussing the effects of compressor efficiency. A stock smic in stock location still yields 65% efficiency before heat soak. And i've seen many a decent ebay FMIC achieve 75% efficiency. I don't see why anyone here can't do the same.

My t3 stage 3 in a BEP housing (larger volume volute than a .63a/r t3 housing) spools to 25psi at 3900-4000 rpms w/ my 60-1 compressor wheel and journal bearing center section. I have no tubular manifold or SMIM; I do have a cam upgrade and full 3 inch exhaust. I know of two gentlemen running 2.0L engines and 56-trims w/ t3 stage 5 turbines and journal bearings. I've seen both reach full spool by under 4500 rpms in .63 a/r housings.

I agree that a discussion like this is quite pointless because we're discussing opinions. Some guys like ball bearing to squeeze every ounce of performance from their setup. Some guys like BB turbos becasue ballistic center sections seam quite indestructable. Also, because it's another step forward in turbocharger technology. But don't be fooled into thinking that it is REVOLUTIONARY. It as a great step, but there is still only a 15% decrease in spool time versus cheaper turbos that can flow nearly the same. As well, BB turbos are coming down in price as we speak.

 

[Steve93Talon]

My t3 stage 3 in a BEP housing (larger volume volute than a .63a/r t3 housing)

You sure about that? I've seen a BEP housing next to a .82 T3 and the BEP looks tiny in comparison. I'd imagine the .63 is still quite a bit bigger than the bolt-on housing.

 

[dsm-onster]

You sure about that? I've seen a BEP housing next to a .82 T3 and the BEP looks tiny in comparison. I'd imagine the .63 is still quite a bit bigger than the bolt-on housing.

Based on a comparision w/ my garrett t3 .63 housing sitting on my t-bird turbo coup. . . Of course, the BEP housing looks thicker on the outside. In all fairness only looking down the throat do you see the difference. I wish I had taken a pic of both these housings looking down the turbine inlet . A .82 a/r housing volute is around 30% larger than a .63 a/r housing. It probalby dwarfs the size of a .63 a/r housing as well.

I of course can be wrong. I havn't cut either housing in two to see for sure. It certainley SEAMS that way. It turns around the turbine wheel at a larger diameter (the bep housing can be cut for quite larger wheels). This makes the volute longer and adds volume. It seams much wider looking down into it. Could it be that just the inlet is cut wider and is fooling me? Yes, but it certainly seams that the larger volute diameter continues around the wheel.

 

[DSM90AWD]

I havn't cut either housing in two to see for sure. It certainley SEAMS that way. It turns around the turbine wheel at a larger diameter (the bep housing can be cut for quite larger wheels). This makes the volute longer and adds volume. It seams much wider looking down into it. Could it be that just the inlet is cut wider and is fooling me? Yes, but it certainly seams that the larger volute diameter continues around the wheel.

Remember, volute area is but one component of A/R. Nossle size/shape has as great (more according to Corky Bell) an impact on gas velocity to the turbine / backpressure. I've had modified Mitsu 7cm cut for a StgIII wheel, BEP StgIII 7cm and a GT .63A/R all in front of me and the GT 63A/R had by far the largest nossle area (e.g. the area directly in front of the turbine blades) followed by the modified Mitsu and then BEP (why it spools so damn fast).

Not my pics, but I believe it was Dave Hall that sectioned a 7cm and BEP some time ago to compare the two:

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Oh and OT I've run 25psi on my old bolt-on 50-trim to 49+lb-min without the aid of AI/WI. Then again my stock 7.8:1 compression helps

 

[dsm-onster]

AWESOME pic! Unless I miss my goal significantly, I'll likely try upgrading my turbine housing first when I max out this turbo.

 

[Steve93Talon]

Here's a pic of the 4 common bolt-ons. As you can see, the PTE emulates the non-symmetrical volute of the MHI housing. The BEP is symmetrical but more oval shaped, and the FP is a true Garrett style teardrop shape.

 

[diambo4life]

Not to mention on a 2.0 vs a 1.6 or w/e honda engine it was you can make same power with smaller hotside due to more displacment.

Not quite. Higher displacement will only shift the curve to the left. You will make the SAME power earlier. It doesn't matter if you put that turbo on a 3.0L Supra. It will make the same HP. The limit is the turbo. Smaller hotside might actually kill power.

 

[Slippi84]

Not quite. Higher displacement will only shift the curve to the left. You will make the SAME power earlier. It doesn't matter if you put that turbo on a 3.0L Supra. It will make the same HP. The limit is the turbo. Smaller hotside might actually kill power.

mk3 supra's are 3.0l engines mk4 the body style your probably refering to are only 2.5l engines and your right I worded that wrong or atleast omitted part of that. The point is the bigger engines can run the same turbo with bigger hotsides and make the more hp obviously but still spool around the same as the smaller hotside on a smaller engine like ours. The easiest way to see this look at all the t70 supra's making like 800whp where as on our cars it's more of a 600hp turbo depening on mods and what not.

 

[Slippi84]

Its interesting to see that Garrett rated the gt30r conservately at 500hp, and this particular gt30r produced 565whp/440tq at 32psi. Garret also rated the gt35r at 600hp, and we produced 654whp/472tq at 32psi.


That right there shows you that garret underates it's turbos as the dyno is always the ultimate bs tester.

 

[ThingyNess]

mk3 supra's are 3.0l engines mk4 the body style your probably refering to are only 2.5l engines and your right I worded that wrong or atleast omitted part of that. The point is the bigger engines can run the same turbo with bigger hotsides and make the more hp obviously but still spool around the same as the smaller hotside on a smaller engine like ours. The easiest way to see this look at all the t70 supra's making like 800whp where as on our cars it's more of a 600hp turbo depening on mods and what not.

Actually, both MKIII and MKIV USDM supras were 3.0L I-6 engines. The MKIII being the 7MGTE, and the MKIV being the 2JZ (turbo or non-turbo, depending on the model.)

The 2.5L I-6 (1JZ-GTE) was only available in non-US markets like Europe and Japan. They were never sold here in North America.

You are correct though in that the larger engines make more power with a turbo sized for the same boost threshold versus a smaller engine. They do *not* however, make more power with the *same* turbo. The supra guys using the T70's are using bigger A/R turbine housings, and often bigger turbine wheels than DSMers do, as a result of their 50% extra displacement they have to play with.

It's not an apples to apples comparison, though. Put a T67 with a P-trim turbine wheel, and say, a .78 T4 exhaust housing on both a DSM and a Supra, and run it near its limits (close to compressor choke flow), and you will find those limits are the same, regardless of whether the turbo is attached to a 2.0L engine, a 3.0L engine, or even a 5.0L V8.

 

[ThingyNess]

Its interesting to see that Garrett rated the gt30r conservately at 500hp, and this particular gt30r produced 565whp/440tq at 32psi. Garret also rated the gt35r at 600hp, and we produced 654whp/472tq at 32psi.


That right there shows you that garret underates it's turbos as the dyno is always the ultimate bs tester.

Keep in mind that Garrett rates its turbos conservatively, and their compressor maps are designed such that you should be able to operate the turbo somewhere on their compressor map and have it last 100,000+ miles with no issues.

Most compressor maps end at the 65-55% efficiency level. For many compressors (and particularly different pressure ratios), this isn't necessarily where the compressor has hit choke yet. It's merely an arbitrary point where they've decided to end the map. Operation outside the limits outlined by the compressor map usually will give you more flow and more power, but compressor efficiency plummets quite quickly, and the sharp increase in shaft speed makes for unhappy bearings, at least long-term.

It's rare to find a turbo that can't make more power than one might think from looking at its compressor map. Operation outside of those limits is not recommended if you want to get an OEM-length (100,000+ mile) life span out of your turbo, though.

Just look at how many stock DSM T25s fail versus how many stock DSM 14bs fail. It's not because the T25 is poorly engineered, but because from the *factory*, Mitsu really pushed the envelope of the poor turbo, and the T25 is already out of its factory recommended compressor map at stock boost. It works of course, and makes more power than its compressor map might suggest. They don't tend to last all that long in the grand scheme of things though - the number of failed DSM T25s with under 75,000 miles is a testament to that. I have a couple of 14bs with 300,000km on them that still have their axial and radial play within spec.

 

[Slippi84]

Keep in mind that Garrett rates its turbos conservatively, and their compressor maps are designed such that you should be able to operate the turbo somewhere on their compressor map and have it last 100,000+ miles with no issues.

Most compressor maps end at the 65-55% efficiency level. For many compressors (and particularly different pressure ratios), this isn't necessarily where the compressor has hit choke yet. It's merely an arbitrary point where they've decided to end the map. Operation outside the limits outlined by the compressor map usually will give you more flow and more power, but compressor efficiency plummets quite quickly, and the sharp increase in shaft speed makes for unhappy bearings, at least long-term.

It's rare to find a turbo that can't make more power than one might think from looking at its compressor map. Operation outside of those limits is not recommended if you want to get an OEM-length (100,000+ mile) life span out of your turbo, though.

Just look at how many stock DSM T25s fail versus how many stock DSM 14bs fail. It's not because the T25 is poorly engineered, but because from the *factory*, Mitsu really pushed the envelope of the poor turbo, and the T25 is already out of its factory recommended compressor map at stock boost. It works of course, and makes more power than its compressor map might suggest. They don't tend to last all that long in the grand scheme of things though - the number of failed DSM T25s with under 75,000 miles is a testament to that. I have a couple of 14bs with 300,000km on them that still have their axial and radial play within spec.

I understand all that the only reason I brought up the point is someone posted earlier that garret rated the gt35r at 62lbs/min and everyone else has it at 65lbs/min. Going along with what you just said the garret rating is somewhat irellevant because most people try and push their turbo to it's limits not to it's suggested limit.

 

[Slippi84]

Actually, both MKIII and MKIV USDM supras were 3.0L I-6 engines. The MKIII being the 7MGTE, and the MKIV being the 2JZ (turbo or non-turbo, depending on the model.)

The 2.5L I-6 (1JZ-GTE) was only available in non-US markets like Europe and Japan. They were never sold here in North America.

You are correct though in that the larger engines make more power with a turbo sized for the same boost threshold versus a smaller engine. They do *not* however, make more power with the *same* turbo. The supra guys using the T70's are using bigger A/R turbine housings, and often bigger turbine wheels than DSMers do, as a result of their 50% extra displacement they have to play with.

It's not an apples to apples comparison, though. Put a T67 with a P-trim turbine wheel, and say, a .78 T4 exhaust housing on both a DSM and a Supra, and run it near its limits (close to compressor choke flow), and you will find those limits are the same, regardless of whether the turbo is attached to a 2.0L engine, a 3.0L engine, or even a 5.0L V8.

My last car was a mk3 7mgte so I understand how the 7mgte,1jzgte,and 2jz(non tubro),2jzgte(turbo) engine apply. Technically there are rare cases where late versions of the mk3's came with the 1jzgte engine and were sold over here and I won't bring up the soarer(1jzgte powered sc300)

Anyway Like I said I already agree with everything you just said. I simply worded my original comment wrong. a 500hp turbo will not make 700hp on a supra just cause its a bigger motor. A turbo tah'ts rated to 300 hp would actualy choke a engine with 400hp stock. As long as cams and other supporting mods are done right I shoudl have said will make more useable power as the powerband will come on sooner.

 

[diambo4life]

Actually, both MKIII and MKIV USDM supras were 3.0L I-6 engines. The MKIII being the 7MGTE, and the MKIV being the 2JZ (turbo or non-turbo, depending on the model.)

The 2.5L I-6 (1JZ-GTE) was only available in non-US markets like Europe and Japan. They were never sold here in North America.

You are correct though in that the larger engines make more power with a turbo sized for the same boost threshold versus a smaller engine. They do *not* however, make more power with the *same* turbo. The supra guys using the T70's are using bigger A/R turbine housings, and often bigger turbine wheels than DSMers do, as a result of their 50% extra displacement they have to play with.

It's not an apples to apples comparison, though. Put a T67 with a P-trim turbine wheel, and say, a .78 T4 exhaust housing on both a DSM and a Supra, and run it near its limits (close to compressor choke flow), and you will find those limits are the same, regardless of whether the turbo is attached to a 2.0L engine, a 3.0L engine, or even a 5.0L V8.

Precisely.

 

[nightspeed87]

My last car was a mk3 7mgte so I understand how the 7mgte,1jzgte,and 2jz(non tubro),2jzgte(turbo) engine apply. Technically there are rare cases where late versions of the mk3's came with the 1jzgte engine and were sold over here and I won't bring up the soarer(1jzgte powered sc300)

Anyway Like I said I already agree with everything you just said. I simply worded my original comment wrong. a 500hp turbo will not make 700hp on a supra just cause its a bigger motor. A turbo tah'ts rated to 300 hp would actualy choke a engine with 400hp stock. As long as cams and other supporting mods are done right I shoudl have said will make more useable power as the powerband will come on sooner.

Keep in mind some of those 2jz guys making more power on the same sized turbos as some of our set ups could quite possibly be due to the fact that some of them are twin turbo.( But we all know two turbos dont always flow more than a single turbo on an inline motor, theres a compramise in either case so this rather depends on the set up. )