The motor is a 1990 Integra LS b18 with around 100k miles using DSM 450 injectors.

Turbo kit is custom equal length manifold, precision intercooler, 3" downpipe.

Right now we are using a giant t3/t4 turbo that is very laggy but makes good top end power. The car went 11.98@117. The car is a 1988 CRX HF.

Do you think the car could be faster with a smaller turbo and wider powerband? What are the whp limits of the standard t3?

 

I think it will go slower.

 

Compressor Map and some simple math will tell you!

 

for a second, i thought this was still in a DA, and was like WHAT! but i see it's in a crx, so that makes sense. i don't know about peak power, but i'm running a t3 .42/.48 in my DA, and it put down 251 whp/ 230 tq. it pulls hard till redline, but i honestly don't think it has much more. it is fun for the street though....

 

bout 260ish WHP off a straight t3

 

you must be running real high injector duty cycle trapping 117 on 450cc injectors. I dont really think you will find much more than around mid to high 200hp with that straight t3

 

Duty cycle was at 103% with 70 psi fuel pressure. Totally maxed.

If we run 25 pounds of boost and make 280 I think we could improve our 1/4 mile times.

 

yeah, the HP is REALLY peaky right now....

i'm not sure how much the current setup will benifit from a better powerband, but if we run an LS trans, i think it'll help quite a bit.

its gonna need a LOT of boost though, i'm thinking about 27-30 PSI from the .42/48... but maybe it'll be too restrictive.

 

duder above is making 250 with only 10 pounds of boost and runs 13.2 with 2600 pound DA.

I think Gutty can make 300 at 20 psi and run 11.6

 

I think it needs a SVO/tbrid turbo .63 exhaust or a older Nissan 280x t3. LS trans just for drag, just swap the night before. I think the .42.48 is to small.

kevron

 

Bigger Injecors Bigger Turbo = Faster times

Also what size slicks? What tuning program? Multi stage boost controller? Boost by gear

Also look into building the head to rev higher and drop into a better spot in the powerband on shifts.

 

45trim compressors are good for roughly 230-250whp. 60 trim compressors are good for about 280-310whp. Figure about 15-17 psi on either turb.

 

I had a t3 .42/.48 on a sohc zc. It took almost 15psi to make just under 220whp. And boost was falling off after 6k.

Honestly, that turbo is too small for your application.

 

haha

 

Give it room to exhale, and it won't 'drop off' as much. You may have missed the earlier post on the smaller T3 making 251whp, and more than a handful have made >310 on a 60trim (although easier with a stg3 exhaust).

The 50trim ".42/.48" map is ideal at ~18psi (I have an AiResearch unit I measured to be 50trim, not 45). Above 22psi or so it really drops off, so at that point you'd want a very effective fmic - no ebay crap for that setup. You'd be best off using a .63ar housing, and seeing if you could get a .60ar comp housing that fits. A few people at HMT have slapped 60trim .60ar comp housings (despite the inducer gap) on 50trim turbos and claimed it was faster at the track.

 

I used that turbo when I boosted my D16 and made 233WHP and 226WTQ @ 16psi. The issue with mine was that I was using a used log manifold that I bought online that I am sure didnt flow very well and my downpipe was only 2.5" all the way back and then the inlet of the muffler was only 2.25". Those issues were probably holding some power back but it did spool very well but as you can see with my graph below it peaked a little before 6k and then started to loose power. I am not sure on comparing stock head and IM from my Y8 to your LS would be but these were my results with my D16.

Also, when it was getting tuned I started to loose the efficiency of turning the boost up after 16psi. It seemed that after that it would only yield me about ~2WHP per psi. But I am sure that this had a lot to do with my cheap beginner setup.

 

most power i ever made is 240's whp with a t3 .42 comp .48 turbine stage 1 wheel

 

get the 60 trim tbird t3 and weld the wastegate shut and let it run as much boost as it can make and if it has external wastegate take the gate off and bolt on a block off plate on the wastegate hole and run as much boost as it will make

it'll make about 450wtq and 330 whp and i hope you have a REALLY good intercooler haha but it'll be faster i guarantee it

or why not just get a holset like a hy35 or a hx35 with a 9cm housing it's very comparable to a .63 t3t4 50 trim and it will have a good powerband if yourev it out to at least 7500 rpms

i would highly suggest the latter and not the first option because the first option will work but with all that torque you may end up throwing a rod actually i would about guarantee you would throw a rod or go lean when it hits that huge torque spike but i've seen it done on a dsm with a t25 instead of a t3 and it didn't hurt it so who knows

but i do know for a fact that a hy35 with a 9cm hotside will be almost identicalwhen it comes to spool and power of a .63 t3t4 50 trim because i've overlayed a vw1.8t 20v one with the holset and one with the 50 trim and they were almost identical from spool up to power output

I don't know about the other holset or any other holset i just know about this one because a guy posted on a vw forum

i have an ITS t3t4 50 trim and i know there rep is bad but its new so.....if it don't last long ill just get the hy35 since its spool and power are identical and you can buy a holset for less than 200 and sometimes less than 100$

get on ebay and find you a holset hy35 or hx35thats my advice to go faster

 

hondas like boost in the top end, its like exponential, i dont like quick spooling turbos for putting down decent numbers, i wouldnt run anthing smaller than a t3/t4 57trim...but with how much whp you can get outta a t3 is too hard to tell, from what you tell us i would say you could see 300, but every setup is different.

my tuners evo has the stock turbo and is putting 100 more whp down than the turbos engineered to actually flow, so it varies really, so you gotta calculate it based on what your running.

plus if you wanna see faster track times gearing is a huge factor. i wouldnt be running an ls trans. a gsr is nice, unless you wanna build a tranny for the track using different gears from difference trannys.

 

we are using WAY too tight a ratio tranny (93 GSR ys1 w/OEM LSD) . it kinda sucks at the autocrosses its been too, shifting too much, etc.

almost running out of 5th gear at 120 MPH. shifting every gear sucks at the drag strip, especially if first is too short to get good traction and 2nd is just a bit too tall to start in.

LS trans FTW

 

also, budget is a HUGE factor....as this is a GRassroots motorspots $challenge car.

24.5x8 slicks.. track wasnt prepped for CRAP though....but we used quite a lot of VHT, and were cutting some 1.8 60 fts (barely)

the current turbo is a 100% peaky powerband, and isnt working well. i think i'm going to send the .42/.48 to our turbo rebuilder (to get clipped/quickspool'd and to put a upgrade wheel/housing on the coldside (old school SVO mustang upgrade part) i think i might have a .63 hotside housing i can put on it (the .48 and .63 use the the same wheel, different housing)

 

no tbird T3 (or any straight t3) is going to make anywhere near 450tq or 330hp especially on a honda. and no t25 has ever made that kind of power either.

 

with the wastegate welded and nothing controlling boost and the turbo making as much boost as it possibly can yeah it could because it would spike to 40+psi and then fall off as the rpm's rise
thats how the dsm did it on a t25 i saw it with own 2 eyes

but thats beside the point if he's looking for cheap power what i wrote about the holsets he should use that advice

 

I made 200whp on my little 45trim t3 at 10lbs with my stock d16y7. I think at 20lbs i could be pretty close to 300. I am also using my hy35 for my build. they are great turbos..... kind of wish i had an hx35 with 12cm housing.

If you are looking for a t3 .42/.48 i have a KKK turbo i got off in the junk yard the other day. its pretty mint and has a waste gate built into the exhaust housing.

 

that 45 trim t3 maxes out at about 240 maybe 250 whp no matter how much boost you run thats all the whp it'll make if you crank the boost even when you are making that much it'll make more torque early but it won't hold the tq as the rpms rise hence why it won't make anymore whp
you get what im saying?

thats how someone i know made 400+ lbs of tq on a 4g63 eclipse t25 he welded the wastegate shut and it hit 40+ psi at about 3k rpms and as the rpms rose the psi dropped and he only made something like 240whp

i know quite a bit about small turbo i drive a 1.8t vw and the stock turbo on these cars are tiny i could spike 25psi and by the time i got to redline the boost would fall to 10psi whi makes it make a crap load of tq and only a max of 240whp or so with all bolt ons