Turbo suggestions?
Turbo suggestions?
04-28-2018, 12:49 AM
#1
My original plan was to have the stock T25 rebuilt with T28 internals, which flows around 34lbs/min. I was planning to set the wastegate to open around 1.5bar. I still might do this, but the cost comes out to around $700, and there is some downtime associated with shipping the original turbo out, and waiting for it to be rebuilt and sent back.
I'm just wondering if anyone has a suggestion for an off-the-shelf solution, maybe a Holsett or something, that would be appropriate for my application (i.e., not overpowering the fuel pump) as well as cheaper than $700.
Thanks.
Bummer-Bob
04-28-2018, 12:49 AM #1I have a 1992 300D 2.5 Turbo (I believe in Europe this car was sold as a 250D Turbo - either way, the chassis coed should be the same, 124.128). I recently installed a Dieselmeken pump with 7,5mm elements, set to about 90cc (or less) of fuel delivery. The car runs great, except I would like a slightly broader powerband (especially low-end), and would like to increase airflow in order to reduce the black smoke at WOT. What I don't want to do is go crazy and try to install the biggest turbo I can find. My OM602 is pretty modest in terms of power output, and even my superpump is more on the conservative side, so I want a turbo that will a match.
My original plan was to have the stock T25 rebuilt with T28 internals, which flows around 34lbs/min. I was planning to set the wastegate to open around 1.5bar. I still might do this, but the cost comes out to around $700, and there is some downtime associated with shipping the original turbo out, and waiting for it to be rebuilt and sent back.
I'm just wondering if anyone has a suggestion for an off-the-shelf solution, maybe a Holsett or something, that would be appropriate for my application (i.e., not overpowering the fuel pump) as well as cheaper than $700.
Thanks.
04-29-2018, 07:07 PM
#2
Similarly, a TD05 16g will flow the same and you can get one with a T3 flange and 10cm housing for $600. The 10cm might not afford a ton of low end boost though, but I cant say for sure.
This post was last modified: 04-29-2018, 07:10 PM by awsrock.
The He221 comes as a t25 flange and flows around 37 lbs / min. Should be available for $600-$700 new, sans adapters and whatnot. I'd say avoid anything less than a 6cm housing though.
Similarly, a TD05 16g will flow the same and you can get one with a T3 flange and 10cm housing for $600. The 10cm might not afford a ton of low end boost though, but I cant say for sure.
04-30-2018, 10:03 AM
#4
(04-29-2018, 07:07 PM)awsrock The He221 comes as a t25 flange and flows around 37 lbs / min. Should be available for $600-$700 new, sans adapters and whatnot. I'd say avoid anything less than a 6cm housing though.
Similarly, a TD05 16g will flow the same and you can get one with a T3 flange and 10cm housing for $600. The 10cm might not afford a ton of low end boost though, but I cant say for sure.
It looks like the HE221s come with a 7cm housing. I did a little bit of reading and skimmed through the numbers, sounds like it might be a really good option for a street-driven OM602, considering my build is more on the modest side. Is it plug-and-play? Or do I need to do any additional work to get the oil drain and everything else to fit properly?
Bummer-Bob
04-30-2018, 10:03 AM #4(04-29-2018, 07:07 PM)awsrock The He221 comes as a t25 flange and flows around 37 lbs / min. Should be available for $600-$700 new, sans adapters and whatnot. I'd say avoid anything less than a 6cm housing though.
Similarly, a TD05 16g will flow the same and you can get one with a T3 flange and 10cm housing for $600. The 10cm might not afford a ton of low end boost though, but I cant say for sure.
It looks like the HE221s come with a 7cm housing. I did a little bit of reading and skimmed through the numbers, sounds like it might be a really good option for a street-driven OM602, considering my build is more on the modest side. Is it plug-and-play? Or do I need to do any additional work to get the oil drain and everything else to fit properly?
04-30-2018, 09:36 PM
#5
You'll have to modify the feed and drain but it isn't that hard...it can seem hard at first. You'll need some silicone adapter to connect intake and the hardest part will likely be getting the exhaust hooked up to your existing. I'll send some ideas tomorrow when I am at a keyboard unless someone beats me to it.
05-01-2018, 09:42 AM
#6
(04-30-2018, 09:36 PM)awsrock You'll have to modify the feed and drain but it isn't that hard...it can seem hard at first. You'll need some silicone adapter to connect intake and the hardest part will likely be getting the exhaust hooked up to your existing. I'll send some ideas tomorrow when I am at a keyboard unless someone beats me to it.
So what's the advantage of the HE221W vs. just upgrading the stock T25 with T28 internals? I mean, the latter would allow for essentially factory fitment, and the flow rates are very similar (37 vs. 34). Is it just the housing size? I don't know what stock size is, maybe 5.5cm? I've seen the HE221W in both 5.5 and 7cm configurations. What is the advantage to the larger housing? I know the smaller ones spool up faster, so you don't want to go too large for your power level, but what would be the problem with staying smaller (i.e., stock size)?
Thanks!
Bummer-Bob
05-01-2018, 09:42 AM #6(04-30-2018, 09:36 PM)awsrock You'll have to modify the feed and drain but it isn't that hard...it can seem hard at first. You'll need some silicone adapter to connect intake and the hardest part will likely be getting the exhaust hooked up to your existing. I'll send some ideas tomorrow when I am at a keyboard unless someone beats me to it.
So what's the advantage of the HE221W vs. just upgrading the stock T25 with T28 internals? I mean, the latter would allow for essentially factory fitment, and the flow rates are very similar (37 vs. 34). Is it just the housing size? I don't know what stock size is, maybe 5.5cm? I've seen the HE221W in both 5.5 and 7cm configurations. What is the advantage to the larger housing? I know the smaller ones spool up faster, so you don't want to go too large for your power level, but what would be the problem with staying smaller (i.e., stock size)?
Thanks!
05-03-2018, 08:02 AM
#7
(05-01-2018, 09:42 AM)Bummer-Bob So what's the advantage of the HE221W vs. just upgrading the stock T25 with T28 internals? I mean, the latter would allow for essentially factory fitment, and the flow rates are very similar (37 vs. 34). Is it just the housing size? I don't know what stock size is, maybe 5.5cm? I've seen the HE221W in both 5.5 and 7cm configurations. What is the advantage to the larger housing? I know the smaller ones spool up faster, so you don't want to go too large for your power level, but what would be the problem with staying smaller (i.e., stock size)?
Thanks!
The HE221 might have better spool but it probably wouldn't be night and day. The compressor map might be better too but I guess it depends on what kind of t28 stuff is going into your turbo. Some place have begun replicating the GT series 11 blade compressor wheels and possibly the turbine wheels too. I'd say as long as what you would swap in is somewhat more modern the difference would be moot. As for the turbine housing, I don't know what the stock t25 is, I do know that the stock t3 was around 6.5cm (.48 a/r)
If you do get a bigger turbine wheel, that will help. You want to be able to flow more exhaust out with the upgraded pump. You could also ask them to port your wastegate as much as possible to help with some backpressure. I'd say overall a good upgrade to your current turbo will probably be a better option when you weigh the convenience of reassembly. Who are you looking at for the upgrade?
I would also recommend looking into a bigger exhaust if you can manage it. The stock exhaust is pretty small and has some VERY small crimps where the downpipe bends (at least, on my SDL there were...as small as 2" in some spots!)
For the record, I have a straight 3" with a Thrush turbo muffler (the quietest one) and it is practically as quiet as stock.
(05-01-2018, 09:42 AM)Bummer-Bob So what's the advantage of the HE221W vs. just upgrading the stock T25 with T28 internals? I mean, the latter would allow for essentially factory fitment, and the flow rates are very similar (37 vs. 34). Is it just the housing size? I don't know what stock size is, maybe 5.5cm? I've seen the HE221W in both 5.5 and 7cm configurations. What is the advantage to the larger housing? I know the smaller ones spool up faster, so you don't want to go too large for your power level, but what would be the problem with staying smaller (i.e., stock size)?
Thanks!
The HE221 might have better spool but it probably wouldn't be night and day. The compressor map might be better too but I guess it depends on what kind of t28 stuff is going into your turbo. Some place have begun replicating the GT series 11 blade compressor wheels and possibly the turbine wheels too. I'd say as long as what you would swap in is somewhat more modern the difference would be moot. As for the turbine housing, I don't know what the stock t25 is, I do know that the stock t3 was around 6.5cm (.48 a/r)
If you do get a bigger turbine wheel, that will help. You want to be able to flow more exhaust out with the upgraded pump. You could also ask them to port your wastegate as much as possible to help with some backpressure. I'd say overall a good upgrade to your current turbo will probably be a better option when you weigh the convenience of reassembly. Who are you looking at for the upgrade?
I would also recommend looking into a bigger exhaust if you can manage it. The stock exhaust is pretty small and has some VERY small crimps where the downpipe bends (at least, on my SDL there were...as small as 2" in some spots!)
For the record, I have a straight 3" with a Thrush turbo muffler (the quietest one) and it is practically as quiet as stock.
05-03-2018, 08:55 AM
#8
(05-03-2018, 08:02 AM)awsrock(05-01-2018, 09:42 AM)Bummer-Bob So what's the advantage of the HE221W vs. just upgrading the stock T25 with T28 internals? I mean, the latter would allow for essentially factory fitment, and the flow rates are very similar (37 vs. 34). Is it just the housing size? I don't know what stock size is, maybe 5.5cm? I've seen the HE221W in both 5.5 and 7cm configurations. What is the advantage to the larger housing? I know the smaller ones spool up faster, so you don't want to go too large for your power level, but what would be the problem with staying smaller (i.e., stock size)?
Thanks!
The HE221 might have better spool but it probably wouldn't be night and day. The compressor map might be better too but I guess it depends on what kind of t28 stuff is going into your turbo. Some place have begun replicating the GT series 11 blade compressor wheels and possibly the turbine wheels too. I'd say as long as what you would swap in is somewhat more modern the difference would be moot. As for the turbine housing, I don't know what the stock t25 is, I do know that the stock t3 was around 6.5cm (.48 a/r)
If you do get a bigger turbine wheel, that will help. You want to be able to flow more exhaust out with the upgraded pump. You could also ask them to port your wastegate as much as possible to help with some backpressure. I'd say overall a good upgrade to your current turbo will probably be a better option when you weigh the convenience of reassembly. Who are you looking at for the upgrade?
I would also recommend looking into a bigger exhaust if you can manage it. The stock exhaust is pretty small and has some VERY small crimps where the downpipe bends (at least, on my SDL there were...as small as 2" in some spots!)
For the record, I have a straight 3" with a Thrush turbo muffler (the quietest one) and it is practically as quiet as stock.
Thanks for all the info, and for being patient with my questions.
I'm looking at a turbo rebuild place called G-Pop Shop. Heard good stuff from them. The upgrade from the stock T25 to what's called the "Big T28" includes a larger compressor wheel, a larger turbine shaft/wheel, and machining of the inside of the stock housing to accommodate the larger wheels. Cost is $695. Advantages are completely stock fitment on the outside, with no modification required. I'll probably just need to order a couple of gaskets and that's it. Disadvantages are longer down time - I need to remove the stock turbo, ship it to the turbo shop (turnaround is supposed to be 5 days), and wait for it to come back before reinstalling. This isn't a huge deal, as I have a second car that I actually prefer to drive in the summer, but it's still a little bit more of a process.
The other option is of course the Holsett HE221W, available here for $680. Advantages are slightly more flow and larger housing, and all-new instead of rebuilt. Plus, I can have it shipped and sitting in my garage, ready for me to swap at my convenience. Disadvantages are potentially more troublesome fitment. Yes, it's a T25 flange which should bolt up to the manifold just fine, but as far as oil drains and correct spacing for the crossover pipe, who knows. It could end up taking even longer to install because of unforeseen issues, trial and error, etc. I mean, I think it will probably be a better turbo, but I'm not sure by how much. And I'm not sure that I'll even be able to take advantage of or notice the marginally better flow.
Thoughts?
Bummer-Bob
05-03-2018, 08:55 AM #8(05-03-2018, 08:02 AM)awsrock(05-01-2018, 09:42 AM)Bummer-Bob So what's the advantage of the HE221W vs. just upgrading the stock T25 with T28 internals? I mean, the latter would allow for essentially factory fitment, and the flow rates are very similar (37 vs. 34). Is it just the housing size? I don't know what stock size is, maybe 5.5cm? I've seen the HE221W in both 5.5 and 7cm configurations. What is the advantage to the larger housing? I know the smaller ones spool up faster, so you don't want to go too large for your power level, but what would be the problem with staying smaller (i.e., stock size)?
Thanks!
The HE221 might have better spool but it probably wouldn't be night and day. The compressor map might be better too but I guess it depends on what kind of t28 stuff is going into your turbo. Some place have begun replicating the GT series 11 blade compressor wheels and possibly the turbine wheels too. I'd say as long as what you would swap in is somewhat more modern the difference would be moot. As for the turbine housing, I don't know what the stock t25 is, I do know that the stock t3 was around 6.5cm (.48 a/r)
If you do get a bigger turbine wheel, that will help. You want to be able to flow more exhaust out with the upgraded pump. You could also ask them to port your wastegate as much as possible to help with some backpressure. I'd say overall a good upgrade to your current turbo will probably be a better option when you weigh the convenience of reassembly. Who are you looking at for the upgrade?
I would also recommend looking into a bigger exhaust if you can manage it. The stock exhaust is pretty small and has some VERY small crimps where the downpipe bends (at least, on my SDL there were...as small as 2" in some spots!)
For the record, I have a straight 3" with a Thrush turbo muffler (the quietest one) and it is practically as quiet as stock.
Thanks for all the info, and for being patient with my questions.
I'm looking at a turbo rebuild place called G-Pop Shop. Heard good stuff from them. The upgrade from the stock T25 to what's called the "Big T28" includes a larger compressor wheel, a larger turbine shaft/wheel, and machining of the inside of the stock housing to accommodate the larger wheels. Cost is $695. Advantages are completely stock fitment on the outside, with no modification required. I'll probably just need to order a couple of gaskets and that's it. Disadvantages are longer down time - I need to remove the stock turbo, ship it to the turbo shop (turnaround is supposed to be 5 days), and wait for it to come back before reinstalling. This isn't a huge deal, as I have a second car that I actually prefer to drive in the summer, but it's still a little bit more of a process.
The other option is of course the Holsett HE221W, available here for $680. Advantages are slightly more flow and larger housing, and all-new instead of rebuilt. Plus, I can have it shipped and sitting in my garage, ready for me to swap at my convenience. Disadvantages are potentially more troublesome fitment. Yes, it's a T25 flange which should bolt up to the manifold just fine, but as far as oil drains and correct spacing for the crossover pipe, who knows. It could end up taking even longer to install because of unforeseen issues, trial and error, etc. I mean, I think it will probably be a better turbo, but I'm not sure by how much. And I'm not sure that I'll even be able to take advantage of or notice the marginally better flow.
Thoughts?
05-03-2018, 02:09 PM
#9
While the holset would be new, you are essentially getting a new turbo in terms of working parts. Bearings, shaft, wheels. The other stuff is just the body really.
I'd be interested to see what turbine they use. I assume the compressor is somewhat updated vs just being bigger, even if it is not an 11 blade GTX wheel. You may want to ask if they can swap one of those in? Actually thinking about it, it must be modern if it flows 34 lbs a min...the stock turbo probably can only do like 28, if that.
Unless you plan on bigger upgrades down the road, I suppose for less hassle the rebuild would be best. And even so, if you got a new manifold and turbo for some crazy power it would probably be T3 anyway so you could just start over.
I agree. Unfortunately (or fortunately?) we are both running 90cc pumps which is not much compared to most, but still enough to need new parts. What I mean is you are right, you probably won't notice much difference between the rebuild and the HE221.
While the holset would be new, you are essentially getting a new turbo in terms of working parts. Bearings, shaft, wheels. The other stuff is just the body really.
I'd be interested to see what turbine they use. I assume the compressor is somewhat updated vs just being bigger, even if it is not an 11 blade GTX wheel. You may want to ask if they can swap one of those in? Actually thinking about it, it must be modern if it flows 34 lbs a min...the stock turbo probably can only do like 28, if that.
Unless you plan on bigger upgrades down the road, I suppose for less hassle the rebuild would be best. And even so, if you got a new manifold and turbo for some crazy power it would probably be T3 anyway so you could just start over.
05-12-2018, 02:34 PM
#10
(05-03-2018, 02:09 PM)awsrock I agree. Unfortunately (or fortunately?) we are both running 90cc pumps which is not much compared to most, but still enough to need new parts. What I mean is you are right, you probably won't notice much difference between the rebuild and the HE221.
While the holset would be new, you are essentially getting a new turbo in terms of working parts. Bearings, shaft, wheels. The other stuff is just the body really.
I'd be interested to see what turbine they use. I assume the compressor is somewhat updated vs just being bigger, even if it is not an 11 blade GTX wheel. You may want to ask if they can swap one of those in? Actually thinking about it, it must be modern if it flows 34 lbs a min...the stock turbo probably can only do like 28, if that.
Unless you plan on bigger upgrades down the road, I suppose for less hassle the rebuild would be best. And even so, if you got a new manifold and turbo for some crazy power it would probably be T3 anyway so you could just start over.
So what exactly would be involved in fitting the HE221W anyway? I'm still slightly leaning this way since I won't have to deal with shipping both directions and waiting for the rebuild.
This post was last modified: 05-12-2018, 02:34 PM by Bummer-Bob.
Bummer-Bob
05-12-2018, 02:34 PM #10(05-03-2018, 02:09 PM)awsrock I agree. Unfortunately (or fortunately?) we are both running 90cc pumps which is not much compared to most, but still enough to need new parts. What I mean is you are right, you probably won't notice much difference between the rebuild and the HE221.
While the holset would be new, you are essentially getting a new turbo in terms of working parts. Bearings, shaft, wheels. The other stuff is just the body really.
I'd be interested to see what turbine they use. I assume the compressor is somewhat updated vs just being bigger, even if it is not an 11 blade GTX wheel. You may want to ask if they can swap one of those in? Actually thinking about it, it must be modern if it flows 34 lbs a min...the stock turbo probably can only do like 28, if that.
Unless you plan on bigger upgrades down the road, I suppose for less hassle the rebuild would be best. And even so, if you got a new manifold and turbo for some crazy power it would probably be T3 anyway so you could just start over.
So what exactly would be involved in fitting the HE221W anyway? I'm still slightly leaning this way since I won't have to deal with shipping both directions and waiting for the rebuild.
05-12-2018, 09:31 PM
#11
Pretty much you'll need to get a new oil feed like and connect it to the block in place of the old one, and likewise with the drain. Then various silicone hoses to connect to the intake manifold. The biggest challenge would probably be getting the turbo to connect to your existing exhaust. If you opt for a new exhaust or even just a downpipe then you can tailor it to connect to the new turbo which will likely be a v band connection
05-14-2018, 02:09 AM
#12
atypicalguy
05-14-2018, 02:09 AM #12Just put new turbine compressor into existing housing. If turbine is not new style upgrade however, then either get a new style bfrom greedy or go with newer turbo and associated headaches. Probably listen to Baldur on that. I imagine he has done his homework. It is not just mass flow, but flow at the desired PR to burn Your fuel given VE, target rpm, desired AFR greater than 17, intercooling and compressor efficiencies. Plenty or spreadsheets available. Plot engine operating rpm points across compressor map. Try to run in The high efficiency part and not surge off the left side.
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