A bunch of turbo questions - Experts only respond please

[Tage]

I consider myself fairly knowledgeable on most (Honda) automotive topics but when it comes to turbos I'm a retard! I understand how forced induction and all the components work but when it comes to knowing the specs of a turbo I am lost. I know that a "T25" is a small turbo and that a GT35 twin scroll or something like that is a bad ass turbo but what do those numbers actually mean?

Is a 16g "9" units smaller than a "T25"? Or is the number just some arbritrary things which is manufacturer specific?

WTF difference is a T3-T04e vs a T3/T4?

Is a GT28R similar to a GT35R just smaller?

What the hell is the "trim" spec?

I'd like to understand turbos better because I will be turboing my K24A2 Civic at the end of the year. My challenge is I will want to stay in the same NASA TT class that I am currently in for when I run NASA events. However, when I do the big time attacks I will want much more power. I don't think one turbo will fit the bill for what I'm trying to do even if I bleed a shit load of the boost out of the wastegate or whatever. Do most turbos utilize the same flange or would I need a different manifold if I am switching out turbos between events?

Goal #1 (Stay in the NASA TTS class): I currently make approximately 230WHP on a Dynapack. The most I can make and stay in my current class is about 280WHP on a Dynojet. I could obviously do that all motor but I'd rather do it via a turbo. The reason being is I'd like to make 275-280WHP as soon as possible in the rev range and then have the engine detuned (via boost fall off or timimg retard or richening the mixture, etc.) in the top end so it basically makes 275-280WHP from let's just say 4500-8000RPM.

Goal #2 (Make big power): For this goal it will be to run the fastest lap time and there aren't any rules against how much power you can make. For this goal, I have the feeling that I'll want a different turbo vs "Goal #1". I'd want power to start coming on by 3-4K with full (or near full) boost somewhere around 5K. If I can get boost to come on sooner great but realistically my engine is almost always between 6-8K with 5K likely being the lowest it ever drops to so quick spooling probably doesn't matter. Some things to keep in mind is that my engine is stock and I don't plan to open it up so I likely need to keep power levels around the 400WHP'ish range at the most for reliability reasons.


So... to summarize:
1. How the hell do you read all the specs of a turbo?
2. If I want to run two different turbos can I use the same manifold and will the oil line/return and charge piping line up the same?
3. What turbo should I go with for my goal #1?
4. What turbo should I go with for my goal #2?

[DXE]

http://www.5150rsx.com/images/engine4.JPG

why not this? just curious

[91DA9]

Not an expert by any means, I'm pretty much on your level where turbos are concerned, however there's some great information here:

http://www.turbobygarrett.com/turbobygarrett/tech_center/tech_center.html

The 'Turbo 101' section is all the basics you probably know already. You'll find at least some of the answers to your major questions in 102 and 103.

[BADCHKN]

I consider myself fairly knowledgeable on most (Honda) automotive topics but when it comes to turbos I'm a retard! I understand how forced induction and all the components work but when it comes to knowing the specs of a turbo I am lost. I know that a "T25" is a small turbo and that a GT35 twin scroll or something like that is a bad ass turbo but what do those numbers actually mean?

Is a 16g "9" units smaller than a "T25"? Or is the number just some arbritrary things which is manufacturer specific?

WTF difference is a T3-T04e vs a T3/T4?

Is a GT28R similar to a GT35R just smaller?

What the hell is the "trim" spec?

I'd like to understand turbos better because I will be turboing my K24A2 Civic at the end of the year. My challenge is I will want to stay in the same NASA TT class that I am currently in for when I run NASA events. However, when I do the big time attacks I will want much more power. I don't think one turbo will fit the bill for what I'm trying to do even if I bleed a shit load of the boost out of the wastegate or whatever. Do most turbos utilize the same flange or would I need a different manifold if I am switching out turbos between events?

Goal #1 (Stay in the NASA TTS class): I currently make approximately 230WHP on a Dynapack. The most I can make and stay in my current class is about 280WHP on a Dynojet. I could obviously do that all motor but I'd rather do it via a turbo. The reason being is I'd like to make 275-280WHP as soon as possible in the rev range and then have the engine detuned (via boost fall off or timimg retard or richening the mixture, etc.) in the top end so it basically makes 275-280WHP from let's just say 4500-8000RPM.

Goal #2 (Make big power): For this goal it will be to run the fastest lap time and there aren't any rules against how much power you can make. For this goal, I have the feeling that I'll want a different turbo vs "Goal #1". I'd want power to start coming on by 3-4K with full (or near full) boost somewhere around 5K. If I can get boost to come on sooner great but realistically my engine is almost always between 6-8K with 5K likely being the lowest it ever drops to so quick spooling probably doesn't matter. Some things to keep in mind is that my engine is stock and I don't plan to open it up so I likely need to keep power levels around the 400WHP'ish range at the most for reliability reasons.


So... to summarize:
1. How the hell do you read all the specs of a turbo?

Kind of hard to explain this one but if your buying a used turbo best way is to get the garrett number and call peakboost/fullrace/etc to find out what turbo it is. the first (t3) is always the back side *turbine* the second t04 is the compressor side. E OR S. s would be the compressor housing e is the smaller standard cover as compared to the s cover which is bigger .70


2. If I want to run two different turbos can I use the same manifold and will the oil line/return and charge piping line up the same?

This depends... As long as you keep the EXACT same cover ect yes... BUT you cant run a ballbearing unit and run a standard journal bearing unit which requires water and has a different center cartridge so positions the turbo a little different.

3. What turbo should I go with for my goal #1?

For this goal i would run a gt28rs with a t3 backside you will get max spool around 25-2800 on your motor. to make 280 you will only need 4-6 pounds

4. What turbo should I go with for my goal #2?

Goal #2 i would run a gt3040r which is a gt30r exhaust side/wheel with a 35r compressor side. I would also buy the gt35r with .63 back side and try both and whichever you feel better with sell the other one.


Ok with both of the turbos i listed you could switch them out no problem :) hope this helps you out man

[JoshDC2]

The garrett information is very informative and is comprehensive. It has just about everything you need to know. even formulas for determining hp and pressure needed ext.

[BADCHKN]

Let me know if you have any other questions tage

[2.3Tnut]

If your talking about a evo 8 or 9 16g then I think that would be a great road race turbo if you build a properly paired manifold. would support a little over 300whp with great response. same with a gt28r with a large exhaust housing(gt28r will make less power than the evo 16g) but there is also the gt28rs and gt2871r that gives you more options. .82 a/r t3 housing is a must with the 28rs or 2871 on a honda
. a gt35r is considerably larger and there are several variants and housings available. for 400whp and response I think a gt3076r may be a good comprimise. t3/t4 is a generalized term. there are 100's of varients. some as small as a t3/t04b all the way up to the massive t3/t67. t04e is a family of t04's. from the small 40trim to the 60trim. if ball bearing $$$ is out of the picture a .63a/r stage II/ t04e 46trim may make the response you like and hold power to redline. and a .48a/r housing is always an option if the response is too slow with the .63a/r but I think with a honda you may sacrifice a little up top with the .48 a/r housing.

[2.3Tnut]

also compression, displacement, and fuel will make a huge determining factor on the setup.

[2.3Tnut]

1. How the hell do you read all the specs of a turbo?
2. If I want to run two different turbos can I use the same manifold and will the oil line/return and charge piping line up the same?
3. What turbo should I go with for my goal #1?
4. What turbo should I go with for my goal #2?

missed this part.

1. on gt series stuff the gt signifies the type of turbo t series is the old stuff gt is the newer stuff. the first two numbers are the frame size(and turbine) of the turbo. gtxx xx could be 20,25,28,30,35,40, ect.... the second two numbers are the compressors major diamter. the following letters stand for additional features the turbo may have. r stands for ball bearing. so a gt3076r is a gt series turbo with a 30 series turbine wheel with a 76mm compressor wheel and ball bearing. nomenclature on the other stuff can get confusing very fast. there are typically several turbine housing options for every frame size of turbo. gt28's typically are t25 based housings. however there are t3 style housings available. a/r of the housing also is also very important. a small a/r will spool faster but often choke in the higher flow areas. larger sacrifices response in favor of flow. but often times keeps back pressure more reasonable wich helps keep egt's lower and the car happier. almost a must on a road race car.

2. yes you could run two turbos on one manifold but you have to be cautious with selection. example is you could get a gt28rs with a t31 style exhaust housing and also get a t3/t4 or a larger gt series turbo with the same t31 style housing so your downpipe and manifold will fit both turbo's. you may have to play with silicone coulplers to get both turbos to fit the intercooler piping but thats a slight issue.

3. i'd go with a gt28rs with a .63 or .82 a/r t31 style exhaust housing if you can afford ball bearing. cheap alternate would be a t31 69trim or 76 trim(aka stage II, III) .48a/r or .63 a/r with a t04e 46 trim compressor. probably 300-400 dollars cheaper than the gt28rs.

4. i'd try a gt3076r with a .82 a/r housing. a cheaper alternate would be a t3/60-1 with at least a t350 turbine wheel(aka stage V) or a modern approach sc61 (t3 hotside t350 wheel with a 35r compressor) you could get a .82a/r stage III/t04e 60trim to make 400whp but you would have to lean on it hard! which you obviously know is a big no no with road racing.

[Rufus]

missed this part.

1. on gt series stuff the gt signifies the type of turbo t series is the old stuff gt is the newer stuff. the first two numbers are the frame size(and turbine) of the turbo. gtxx xx could be 20,25,28,30,35,40, ect.... the second two numbers are the compressors major diamter. the following letters stand for additional features the turbo may have. r stands for ball bearing. so a gt3076r is a gt series turbo with a 30 series turbine wheel with a 76mm compressor wheel and ball bearing. nomenclature on the other stuff can get confusing very fast. there are typically several turbine housing options for every frame size of turbo. gt28's typically are t25 based housings. however there are t3 style housings available. a/r of the housing also is also very important. a small a/r will spool faster but often choke in the higher flow areas. larger sacrifices response in favor of flow. but often times keeps back pressure more reasonable wich helps keep egt's lower and the car happier. almost a must on a road race car.

2. yes you could run two turbos on one manifold but you have to be cautious with selection. example is you could get a gt28rs with a t31 style exhaust housing and also get a t3/t4 or a larger gt series turbo with the same t31 style housing so your downpipe and manifold will fit both turbo's. you may have to play with silicone coulplers to get both turbos to fit the intercooler piping but thats a slight issue.

3. i'd go with a gt28rs with a .63 or .82 a/r t31 style exhaust housing if you can afford ball bearing. cheap alternate would be a t31 69trim or 76 trim(aka stage II, III) .48a/r or .63 a/r with a t04e 46 trim compressor. probably 300-400 dollars cheaper than the gt28rs.

4. i'd try a gt3076r with a .82 a/r housing. a cheaper alternate would be a t3/60-1 with at least a t350 turbine wheel(aka stage V) or a modern approach sc61 (t3 hotside t350 wheel with a 35r compressor) you could get a .82a/r stage III/t04e 60trim to make 400whp but you would have to lean on it hard! which you obviously know is a big no no with road racing.

Why can't all newbies be this helpful? Kudos to you Sir.

[Tage]

Wow! Thanks a ton guys. This information far exceeded my expectations! AZHT isn't full of dumb asses after all! LOL

P.S. Goran, I don't want to SC my car because:

1. I don't want to loose my PS
2. I don't want to cut a hole in my hood
3. I don't want the weight so far forward
4. I want more tuning options with a turbo

[Tage]

Looks like two recommendations for a gt28rs. BADCHKN, you also estimate that with a t3 backside I'll get full boost before 3000rpm and only need 4-6 psi to make 280. This seems very reasonable and exactly the range I was looking for. What do you estimate the max that turbo would flow? It certainly would be a hell of a lot easier to just install ONE turbo and then just change the KPro maps to adjust the boost level and tune. I know I won't be making any 400WHP with a gt28rs but would this thing hold 10psi up to 7500rpm and maybe make 350WHP?

[The President]

Looks like two recommendations for a gt28rs. BADCHKN, you also estimate that with a t3 backside I'll get full boost before 3000rpm and only need 4-6 psi to make 280. This seems very reasonable and exactly the range I was looking for. What do you estimate the max that turbo would flow? It certainly would be a hell of a lot easier to just install ONE turbo and then just change the KPro maps to adjust the boost level and tune. I know I won't be making any 400WHP with a gt28rs but would this thing hold 10psi up to 7500rpm and maybe make 350WHP?

lots of 240 guys use the GT2871 and see #'s around 350 so I don't think this is out of the questiion for you by anymeans.

[2.3Tnut]

based of dyno's i've seen the gt28rs falls off around 12psi and typically makes around 325whp max at 10-12psi. flat tq curve from 4k to 8k. http://forums.evans-tuning.com/viewtopic.php?f=27&t=3615&p=21385&hilit=gt28rs#p21385
if your looking for a single turbo to do the job you may want to step up to the gt2871r with a .82a/r t3 housing. i've seen this turbo make 425whp on 24psi and still has decent response. makes usuable power from 4k-4.5k(200+whp) and you could always just buy a .63 or even a .48 a/r housing for when you want better low end power for the lower hp and just throw in the .82 housing and change maps for the big races.

[*inFamous*]

Tage I used a GT2871 for a while (unmodified) and made 300whp easily on 8psi on a B series.. will be no sweat with a K monster :) Its a AWESOME turbo

[Tage]

GT2871 sounds good as well but remember I have to be able to detune it so it makes absolutely no more than 280WHP on a dynojet. If bleeding off boost so it's only 3-6psi isn't a problem then it sounds like perhaps going for a turbo in the middle of what I want is the way to go.

I am also curious about heat. Does a bigger turbo that bleeds off a bunch of excess boost via a wastegate run cooler than a smaller turbo that runs at peak or is there just too many variables to answer that one?

How about the 16G (which sounds like an Evo turbo)? I have to imagine these are somewhat plentiful on the used market and I'm guessing are less expensive than a GT28xx. This turbo can give me big enough number for the big events but can it be successfully detuned to make super low boost and still be responsive?

[Agent Smith]

Corky Bell's book 'Maximum Boost' (http://www.amazon.com/Maximum-Boost-Turbocharger-Engineering-Performance/dp/0837601606) answered a ton of my questions when I 1st got into wanting a turbo car.
1st off yes most "#'s" are manufacture specific, however you have a couple of key things all companies use were already covered, compressor & exhuast flange size, & housing sizes...

16,18, & 20G turbo's are all small Mitsubishi turbos...

If I were you I would run 1 turbo & simply get a boost controller, tune for various conditions, & keep the boost level at something 3-6psi to get your 280whp, then add X psi to get the new WHP you want.

A forewarning, boost is addicting :grin:

[2.3Tnut]

GT2871 sounds good as well but remember I have to be able to detune it so it makes absolutely no more than 280WHP on a dynojet. If bleeding off boost so it's only 3-6psi isn't a problem then it sounds like perhaps going for a turbo in the middle of what I want is the way to go.

I am also curious about heat. Does a bigger turbo that bleeds off a bunch of excess boost via a wastegate run cooler than a smaller turbo that runs at peak or is there just too many variables to answer that one?

How about the 16G (which sounds like an Evo turbo)? I have to imagine these are somewhat plentiful on the used market and I'm guessing are less expensive than a GT28xx. This turbo can give me big enough number for the big events but can it be successfully detuned to make super low boost and still be responsive?


a smaller turbo typically will generate more heat via compression than a larger turbo. it also restricts exhaust flow more which in turn elevates back pressure and ultimately egt's. a larger turbo working less will generate less heat but may be harder to controll boost at lower boost levels. this is where a quality large wastegate will help dramatically.

i'm personally a big fan of the new evo turbos. having the twin scroll housing with a properly built manifold does wonders for response without sacrificing power up top. best of both worlds. it helps by pairing apposing cylinders to help with exhaust scavenging. I know the turbos are also happy at high boost pressures. although I have never seen one maxed out on a honda you can see it has very similar response(if not better) than the gt28rs and they can be picked up for usually less than $300-400 used from people who upgrade there evo's. the evo 9 has the largest exhaust housing and lighter wheels which i think would be very benificial to you. here's a gsr that put down 300whp on 12psi with pump fuel. http://forums.evans-tuning.com/viewtopic.php?f=27&t=4926&p=26816&hilit=EVO#p26816
p.s. a evo 8-9 16g is much larger than the older 16g's. almost comparable to the old 20g's. I won't even try to explain mhi(mitsubishi) turbo nomenclature. it's pretty inconsistant.

another thing to take into consideration is running a big wastegate(ie tial 44mm) will help you control and maintain your 280whp. you just have to make sure you keep the gate divided all the way to the valve to keep the exhaust scavenging effect.

on another note. I'd strongly advise that you do not retard ignition timing or richen the mixture to keep power down. doing so will raise your egt's and elevate engine temps. which again is a no no when your under full power for 20-25 min at at time. use boost to regulate power! this is where the bigger wastegate comes into play. ;)

[taggart_lumpy]

when you need a manifold and kit built give me a shout and i will definately get you set up with what you need

feel free to come on down to the shop anytime and we can sit down and crunch numbers and get 1 single turbo picked out for your goals

talking in person and being able to show things is so much nicer than writing on the internet

our shop is only a few miles from your house too

:thumbup:

[KingDingaLing]

28rs would be perfect

[locash]

I'd take the GT3076R with the .63ar housing for your goals, and can show you the results of it from my K24a2 Integra.

The other option I might consider is the GT2876R with the .86AR housing.. Either one will meet your needs.

[BADCHKN]

Wurd he just never said how much power he is wanting to do for goal #2 thats why i said 35r im sure this motor will almost always be between 4-8k in rpms.

[michalo187]

I'd take the GT3076R with the .63ar housing for your goals, and can show you the results of it from my K24a2 Integra.

The other option I might consider is the GT2876R with the .86AR housing.. Either one will meet your needs.

X 2 I have a gt3076r and I love the spool up on this and the fact it has ball bearings. This turbo spins so freely you can hear it spinning after I shut the car off. I make 260 whp @ 8 psi on a b18c with s300 tuned by locash.

[Tage]

Freaking awesome information guys! Keep it coming.

So far it's been narrowed down to either a GT28xxR, GT3076R or potentially a 16G Evo 8/9 turbo (<-- since I'm a cheap ass). I'm hearing a lot of peak numbers but I would like to see some dyno charts so I can see how linear (or non-linear) the power comes on.

Hey Locash, can I drive your Integra sometime to see how that feels? :)

[BADCHKN]

The only reason i would stay away from an evo turbo is now your limited on your turbo selection and you will have to make a 1 off manifold just for it..

honestly go with a gt3076r... Usually you see 20-25whp per pound of boost... sooo think of it like that

[Kinetic]

Tage-

I will have Tony call you on Monday......also, Ksport used a Full Race turbo kit on their Type R TA car.....makes stupid pwer on low boost. Locash should have the dyno available

[frtech]

Freaking awesome information guys! Keep it coming.

So far it's been narrowed down to either a GT28xxR, GT3076R or potentially a 16G Evo 8/9 turbo (<-- since I'm a cheap ass). I'm hearing a lot of peak numbers but I would like to see some dyno charts so I can see how linear (or non-linear) the power comes on.

Hey Locash, can I drive your Integra sometime to see how that feels? :)

How much power are you looking to make?

Can I drive your car too Joey? I wanna see what all this K-series mumbo jumbo is about.

[rudsone]

damn, i just learned a bunch too!

you guys rock!

[Rob x3]

damn, i just learned a bunch too!

you guys rock!

x2

im like a sponge... i'll be boostin my cb7 soon

[frtech]

Take a look at this link.

http://www.full-race.com/catalog/product_info.php?cPath=22_716_899_902&products_id=1707

It explains the differences between the turbos Full Race offers for the K-series engine.

[onefst91hatch]

i say GT2876R. i have seem this turbo make over 400 HP on a stock D16Z6 built by epic tuning. and the turbo comes in strong and pretty early on that little engine so your 2.4 should have no problems keeping that thing in boost at all times. as long as your using a good design manifold and turbo setup this turbo should be perfect. and using a 44m waste gate is a must if your already at 230ish to the wheels and you can only go to 280. you are not gonna need much boost at all to achieve that. i say 3-4 PSI at most. you could even run the synapse 50mm waste gate which i have not used personally but have heard nothing but good things about it. and it uses the same flange as a tial 44 so if you dont like it then you could just switch to the tial.but with you haveing a 2.4, with that size turbo, wanting to run that little of boost, you are gonna need a big gate. and i would just get the smallest spring you can find for the gate and let Kpro do the rest. you are gonna need a small spring to stay at or under you 280 whp any ways. then when it come time for the time attack you can just turn it way the hell up. lol. gl with your build man. cant wait to see it in the works.