T25


fiberglasscivic
01-16-2007, 03:02 AM
Ok, I'm trying to plan my setup for my 93 Civic Si. I want to turbo, there's no question about that. I'm not looking to make a 10 sec 1/4 mi. I'm more into circuit and road racing. I want to be able to make good power throughout the majority of my power band. Obviously I need something that will spool quickly and to a decent ammount of boost. I'm now looking into puting a B series into my car. I currently don't have an engine but may have a B18C1 within the next few months (depending on whether or not I can scrounge the money up for 94SolGirl before she sells it). If not then I'm really leaning towards a B16B primarily for the fact that it's a rarity and that if I have it I'll be the only one in my area with one (it would be frickin sweet to put in my sig too).

Ok here's what I would like to know (and any other advice you may have would be greatly appriciated). I have been informed (from several people) that the T25 is a great turbo for quick spools and that it can produce around 13 psi. Would a T25 fit what I need best or, is there a better turbo for what I'm looking for. Also (seeing as how I'm in the market for an engine) how well does the B16B and the B18C1 take to boost and is there a better engine candidate for a road circuit boost setup?

I'm willing to listen to any suggestions or experience information about the matter.

PWMAN
01-20-2007, 07:57 AM
With a T25 you would top out at probably 225 WHP no matter what you did, it's a very small turbo.
A good choice for fast spool and good power is a straight T3, 50 trim with the .48 turbine. That turbo is good for around 275-300 WHP, easily 12's with that. That one is still very good for autocross, spools very fast.
Do NOT get into hybrid T3/T4's, they are very laggy. Stick with a straight T3 and go for the .48 turbine housing not the .63.
If you are lucky enough to find a super 60 go with that, but be careful because most super 60's come with the .63 turbine which would cost you about 500 RPM spool-up. If not, the regular 50 trim T3 is still WAY better than a T25.

Schister66
01-20-2007, 12:25 PM
Do NOT get into hybrid T3/T4's, they are very laggy

I dont think that's necessarily true, but i do agree with the rest of what you say. I guess i dont know what you consider lag, but if you bought a T3/T04E 50 trim, you could make full boost on a log at 4200 or so rpm. I have the setup in my sig and see full boost on my grandpa turbo at 5200rpm. That is laggy, but it does make good power. On 9~10psi i'm looking at 330-340whp.

T25 is not a good choice because they dont make crap for power....if you're going to spend the money to turbo your car, get at least a T3 .42/.48 at VERY LEAST

s2k_02_12
01-20-2007, 01:48 PM
Hey I need some info on a s2000.Just purchased one. I wanted to know some steps on what to add on the car from one thing to the next for hp. What should i get first.

Schister66
01-20-2007, 02:57 PM
start a new thread rather than jacking this one....

Schister66
01-20-2007, 02:58 PM
B18C1 would be my pick for a turbo engine...the B16B has higher compression and since it is a smaller dispacement engine, you're not going to spool as fast plus the B16b is spendy. Get a GSR, simple turbo setup and you'll have fun. I can help you build most everything if you want, plus i have good used parts for sale still...lol

fiberglasscivic
01-20-2007, 07:33 PM
I appreciate the info. Schister do you know about how much power I would lose by using a CTR engine rather than a GSR. I know that the compression in the CTR is high but you can purchase low comp pistons and I really don't mind spending the money on it. I'm not looking to peak the ammount of hp my car can put out, I'm just looking to make a nice ammount of power at the wheel. I don't really want to go over 300 hp unless there's no avoiding it. I want the engine to be durable enough to use as a daily driver but strong enough to do some Autocross here and there. I've thought about doing shows too (one of the reasons I want the CTR engine).

So I'm looking at a T3, 50 trim with the .48 turbine. I'm not going to go cheap on this so a log many is out, I want an equal lenth ram horn or something similar. I know they take up space but after reading Schisters how to thread (and before it disappeared) it was obvious that it was worth the loss of space. I'll repost more tomorrow.

Schister66
01-20-2007, 07:58 PM
there is no benefit to getting the B16b if you're just going to change out the bottom end anyway...that's like buying a Bentley and stripping the interior out.

If you want a really fun turbo setup, i can hook you up w/ one like mine. I have over $4k into it, but it will make stupid power on a built engine.

Add me on MSN and/or AIM and we'll talk this over in person rather than just posting back and forth

Schister66
01-20-2007, 08:01 PM
by the way, your best bet if you want a fun car is this.....

-GSR engine (built or stock doesn't matter because i dont think you want crazy power anyway)
-good equal length manifold (ram or topmount)
-3" dp and exhaust
-T3/T04 50trim .63ar exhaust (could even opt for the .48)

that would give you a wicked powerband and could still make good power up top....300+whp isn't out of the question and you'd spool at around 3800-4000 full boost...that means you'll see power at 3k, just not full power

fiberglasscivic
01-21-2007, 07:06 AM
Alright so the B16B is out for a turbo set up. It's funny you said that after Henry calls and tells me that he'd come down here, kick my a**, and call me a silly ricer if I turboed a CTR engine.

PWMAN
01-21-2007, 07:31 AM
I dont think that's necessarily true, but i do agree with the rest of what you say. I guess i dont know what you consider lag, but if you bought a T3/T04E 50 trim, you could make full boost on a log at 4200 or so rpm. I have the setup in my sig and see full boost on my grandpa turbo at 5200rpm. That is laggy, but it does make good power. On 9~10psi i'm looking at 330-340whp.

T25 is not a good choice because they dont make crap for power....if you're going to spend the money to turbo your car, get at least a T3 .42/.48 at VERY LEAST


Yes 4200 is extremely laggy for autocross!!! For autocross you want full boost no later than 3200 RPM, and a 50 trim T3 (.42/.48) comes in right around 3000 or a little better with most setups.

If you go with a hybrid T3/T4 please DO NOT get the .48 turbine, thats just asking for compressor surge! A hyrbid is not a choice for autocross, simply too laggy. Like he said he's not going for high power, just good power with fast spool which is exactly what a straight T3 50 trim will do.

fiberglasscivic
01-21-2007, 08:32 PM
I've been looking for a turbo that matches the 50 trim level and .48 turbine and I haven't seen one yet. Does anyone have a model number?

PWMAN
01-22-2007, 08:12 AM
I've been looking for a turbo that matches the 50 trim level and .48 turbine and I haven't seen one yet. Does anyone have a model number?

Are you sure you're looking at a T3 50 trim, not a hybrid T4 50 trim?
Turbonetics is usually decent-
http://www.eiptuning.com/eip/turbochargers.html
^They have the 50 trim, 60 trim, and super 60 all with the .48 turbine and same price. I'd go with the super 60, better flow for a 16 valve engine.
These people have the same thing-
http://www.agpturbo.com/product.php?productid=16143&cat=252&page=1

Schister66
01-22-2007, 08:29 AM
For AutoX, a T3/T04E 50 trim would be fine on a good manifold. It would spool up quickly and give you power all the way through redline. If you're really worried about having lag, then go w/ a straight T3 like PWNMAN has been saying. Personally i like to make a little power and i'm not afraid of a little lag so i would go w/ a hybrid.

Another option, if you have the money, is the GT28RS...that turbo will give you the power of a Hybrid (because it is one) with the spool time of a straight T3...the only problem is that it is about $1200 brand new....

PWMAN
01-22-2007, 04:21 PM
For AutoX, a T3/T04E 50 trim would be fine on a good manifold. It would spool up quickly and give you power all the way through redline. If you're really worried about having lag, then go w/ a straight T3 like PWNMAN has been saying. Personally i like to make a little power and i'm not afraid of a little lag so i would go w/ a hybrid.

Another option, if you have the money, is the GT28RS...that turbo will give you the power of a Hybrid (because it is one) with the spool time of a straight T3...the only problem is that it is about $1200 brand new....

Have you ever done Autocross? On my setup, 70 trim T3 with .63 stage 1 turbine I have full boost at right around 3200 RPM, and I would STILL consider that slightly laggy for autocross. The stock turbo on my car is a 50 trim T3 and .48 turbine, and with all the mods I have I spooled that to full boost at 2400 RPM. But, I have 2.2 liters. So with a 1.8L or 1.6L the spool is a few hundred RPM more. He should have full boost right around 2800-3000 RPM which in my opinion is pretty good for autoX.
If you can find a stage 1 turbine wheel, the 50 trim TO4E *might* spool full boost a hair before 4000 RPM, but thats still laggy. Plus it's hard to find stage 1 wheel, they are mostly stage 2 or 3, each stage costs about 500 RPM spoolup.
Hah, ceramic BB would be nice, but I can't afford it. Certainly if the FIBERGLASSCIVIC can, go for it. It's the best of both worlds.

fiberglasscivic
01-23-2007, 06:50 AM
Schister, was the information on how to read compressor maps part of your how to guide?

fiberglasscivic
01-23-2007, 06:58 AM
Hah, ceramic BB would be nice, but I can't afford it. Certainly if the FIBERGLASSCIVIC can, go for it. It's the best of both worlds.

Nice.

What type of car are your talking about where spooling at 3200 is laggy, if my civic spools up to full boost at 3200, I'll be really impressed because that gives me about 4000 rpms with full boost (and I think the GSR engine revs higher than 7000 but whether or not it makes power above that IDK). From my little experience (and my experience isn't enough to brag about) 4000 rpms of full boost is excellent. Someone correct my if I'm wrong but it would be very difficult to get full boost at anything lower than 3000 rpms.

PWMAN
01-23-2007, 08:17 AM
Nice.

What type of car are your talking about where spooling at 3200 is laggy, if my civic spools up to full boost at 3200, I'll be really impressed because that gives me about 4000 rpms with full boost (and I think the GSR engine revs higher than 7000 but whether or not it makes power above that IDK). From my little experience (and my experience isn't enough to brag about) 4000 rpms of full boost is excellent. Someone correct my if I'm wrong but it would be very difficult to get full boost at anything lower than 3000 rpms.

My car spools 22 PSI at 3200 RPM, but I have MANY mods aiding spoolup including larger displacement (read my sig, 2.2L). With a straight T3 50 or 60 trim, you will have full boost around 3000 RPM. A T25 would spool around 2500 RPM, but that turbo is horribly restrictive above 5000 RPM....NOT a good choice for a honda engine since they make most of their power above 5000.

Schister66
01-23-2007, 12:06 PM
this is a quick HOW TO: Read Compressor maps
the info below is for my old turbo....T3/T04E 60trim .63ar

1-left side, PRESSURE RATIO(14.7 + amount of boost) / 14.7 = PR
so to figure out the PR for 8 PSI
(14.7 + 8) / 14.7 = 1.54 PR


2-bottom side, AIRFLOW RATE UNDER BOOST (LB/MIN on this map)Most methods of calculation your engine's airflow rate will give you the answer in cubic feet per minute (CFM). However most compressor maps measure airflow rate in pounds per minute (LB/MIN). As some of you may know the weight of air varies with the temperature. To convert CFM to LB/MIN use the following numbers.
@ 48 degrees F : (CFM * 0.078125) = LB/MIN
@112 degrees F : (CFM * 0.070318) = LB/MIN
@175 degrees F : (CFM * 0.06251) = LB/MIN

Say for example our airflow rate is 500 CFM , and the temperature is 112 degrees F.
(500 * 0.070318) = 35.16 LB/MIN

*For those of you that know anything about ideal gas law, if you know a better way of explaining how to convert CFM to LB/MIN, your input would be appreciated. But please explain it in "laymans" terms, so that everyone can get a grasp on it.

3-dotted line on far left side of "ovals", SURGE LIMITIt is important to try and keep yourself on the right side of this dotted line whenever possible. If you fall to the left of this dotted line you will experience compressor surge. This type of compressor surge will occur when there is too much boost, but not enough airflow through the system, usually this is between idle and the point at which full boost is reached. The chirping sound that can be heard is a result of the oscillating air. This sound is often described as a "Snakelike" sound or a che-che-che sound.

*staying in the "surge limit" area for too long could possibly damage your turbo.


4-numbers on far right, 46,020, 69,640, 83,972 etc, COMPRESSOR RPMThis is RPM at which the compressor fans will be turning. an average RPM is between 90,000 and 130,000. The line that branches out from each of these numbers that goes towards the surge limit line shows you the RPM range of the compressor fan across the entire compressor map.


5-78%,75%, 74%, COMPRESSOR EFFICIENCYThis is related to the temp of air and how much it is being heated up as it is being compressed by the compressor. A low number (60%) means that the compressor is heating the air more a high number (78%) means the air is not heated as much when it is compressed.


6-"Ovals"I you look closely you will see that the compressor efficiency numbers usually sit right on top of one of these Oval lines. These Ovals show you the boundaries of the compressor efficiency at the different percentiles. Think of it as a topography map that shows you different elevations or changes in elevations. The innermost Oval on the sample T04 E 60" is not labeleb but it is probably 79% or 80%, so any where inside that Oval and you would be operating in the 80% range of that compressor.

Schister66
01-23-2007, 12:10 PM
to add to the discussion so far....i would never want a turbo that spools fully at 3000 rpm because that would just die up top. I can see a turbo like that on your 2.2L because it probably redlines at 6500rpm, not 8600rpm like my GSR. I do see your point, but i wouldn't ever want that shitty powerband...if you want a quick spooling turbo that's going to die out up top, just get a supercharger and be done with it. Also, if you get a GSR, the gearing is close enough where its not going to matter...just downshift and you're in boost again.

Also FiberglassCivic, how much AutoX racing are you going to do...if you're not going to do a lot, then why tailor your setup entirely to that??

PWMAN
01-23-2007, 12:49 PM
to add to the discussion so far....i would never want a turbo that spools fully at 3000 rpm because that would just die up top. I can see a turbo like that on your 2.2L because it probably redlines at 6500rpm, not 8600rpm like my GSR. I do see your point, but i wouldn't ever want that shitty powerband...if you want a quick spooling turbo that's going to die out up top, just get a supercharger and be done with it. Also, if you get a GSR, the gearing is close enough where its not going to matter...just downshift and you're in boost again.

Also FiberglassCivic, how much AutoX racing are you going to do...if you're not going to do a lot, then why tailor your setup entirely to that??

A good point. So, this all hinges on what engine he actually swaps in. With a B18B1, I would still go with a 50 or 60 trim T3 with the .48 turbine. With a B18C1, perhaps a super 60 with the .63 (stage 1 turbine wheel ONLY) would be good....about 500 RPM slower spoolup but much better top end.
I know with my stock turbo (50 trim T3 with .48)I shifted at 6000-6250 RPM, now I shift at more like 6750 with my 70 trim T3 and .63. Not all of that is the turbine, a larger compressor helps top end too. But, me running out of power at 6250 is not accurate to this discussion since I have a 2.2L versus a 1.8. A 1.8 would still be good until 7000 RPM with the .48 turbine, especially with the super 60 compressor wheel instead of the 50 trim. So, A B18B1 redlines at 7 grand, so a 60 trim T3 is perfect all around turbo for autoX and daily driving.
What also hurts spoolup on hybrids is their heavy compressor wheels, T4 wheels take a lot to spin. T3 wheels are light, therefore just because they are spooling at the low RPMs doesn't mean they are going to be restrictive up top. The lighter wheels helps it spoolup faster so you have power at low RPMs and upper RPMs which is great for AutoX.

fiberglasscivic
01-24-2007, 08:59 PM
Also FiberglassCivic, how much AutoX racing are you going to do...if you're not going to do a lot, then why tailor your setup entirely to that??

I want to race at least once a month when my setup is complete and more if I can afford the dent in my work schedule. I want to taylor to autocross because I'm not that interested drag racing. I don't see as much of a challenge in it like there is in autocross. And around here I have nowhere to drift. (Although I don't think the Civic makes a good drift car.)

Thanks for the how too for the compressor maps. That helps alot.

A good point. So, this all hinges on what engine he actually swaps in.

I think my mind is made up when it comes to the engine. After talking to you guys and Ridestreet84, I'm not going to turbo a B16B. The B18C1 is readily available, so if I can get it then that's the way I'm going.

I need to look at the Super 60. I'll post again in a few minutes. Thanks for everything so far. I don't have anyone around where I'm at to talk to about this.

PWMAN
01-24-2007, 09:40 PM
Personally I would go with the B18B1, low end power is better with autoX. Although I know a go with an S2000 that does autoX thats pretty good, his is N/A power not turbo.
Also, for a turbo application the lower compression is better. Stock for stock, the B1 can handle more boost. The GSR can only boost about 8-10 PSI, I've heard a reliable 14 PSI before on the LS. Beyond 14 PSI or about 300 WHP the pistons melt or break, doesn't matter really what you do.
There's a lot of debate whether or not the GSR tranny has better gearing, my opinion is that for turbo the LS tranny is better. The longer gearing helps make the turbo work, turbo's react to load. The more load the more they will push. You will find in factory turbo cars the gearing is very long, I just don't understand how people can argue with that. Now, don't get me wrong here the LS tranny has short gears compared to my daytona. My mother owns a 2000 GS, and at 70 MPH she's turning over 3000 RPM....I'm at 2200. I believe a GSR is something like 3500 at that speed? Not really sure. Anyway, it's up to you but personally I'm not a big fan of VTEC with turbo and the GSR's tranny and high compression. Fully built of course the C1 will kill, but thats with different cams and pistons ETC which is mega bucks.

Schister66
01-25-2007, 12:34 AM
The best combo for boost is an LS/VTEC....even though the LS may be albe to handle more boost, it isn't going to matter because the head is so restrictive. If you're going for a stock engine, the GSR is better than the LS simply because the off boost is going to be fast and the on boost is going to be faster...also if you're using a little turbo, it isn't going to matter what can hold more power (not psi) because you'll be well under the limit.

If you are really serious about the whole AutoX thing, get a ramhorn, 3" dp and a Garrett GT28RS, but other than that, get the Super 60. If you're looking, i have a buddy who is selling a SPoolin performance ramhorn and 3" dp for a good price right now so that he can fund his new build. He's copying my topmount...lol.

Good luck on the setup...it should be a ton of fun!


I'm not a big fan of VTEC with turbo and the GSR's tranny and high compression

the engine is built really well and i can tell you first hand that it is a ton of fun and can handle a lot of power....the gearing coupled w/ the offboost power would make for a perfect AutoX car.....

fiberglasscivic
01-25-2007, 03:47 AM
Alright, I'm going to keep all this in mind while I'm shopping. I'll let you guys know what I end up using. I sure as hell know it won't be an LS/VTEC, I've heard too many bad stories about them. They might be great for a temp build but I want to do everything right from the get go. Thanks for all the advice. I know I'm pointed in the right direction.

Schister66
01-25-2007, 10:09 AM
actually most people making big power numbers are using LS/VTECs because they're cheap and easy to build. You need to know what you're doing or you will have problems though. If you need anything, just let me know and i'll give you a hand.

ridestreet84
02-09-2007, 10:38 AM
Alright so the B16B is out for a turbo set up. It's funny you said that after Henry calls and tells me that he'd come down here, kick my a**, and call me a silly ricer if I turboed a CTR engine.
damn straight i would call you a silly ricer finally someone has talked sense into you.

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