Guest TurboSedan Posted August 22, 2005 Report Share Posted August 22, 2005 well with the T67 on a 3.1 liter im sure i could see boost at around 4k considering the redline is 5500 RPM on 3100, i would be wanting to boost well before 4000 RPM. i agree it is way too big. Quote Link to comment Share on other sites More sharing options...
FastSE2DR Posted August 22, 2005 Author Report Share Posted August 22, 2005 the redline is 6k on a 3100... Quote Link to comment Share on other sites More sharing options...
bartonmd Posted August 22, 2005 Report Share Posted August 22, 2005 i mean i see what your saying but im not looking at maxing out my turbo to make the power i want...i agree that i just picked out a T67 without looking around much but it was just to get an idea going...i know id need to find a big turbo that would be efficient and have the highest flow rate at the 8-10psi i want to make my power at...you see what im saying? I dont want to run 25-30psi to make power i want to be able to make power at 8-10psi...i dont want a turbo that matches my motor perfectly for street driving...who cares its an NA car already and if i have to wait awhile for spool itll just be like normal until then...like i said i dont want a turbo that has to max out to make 400hp...is that a better explanation so it doesnt seem like im just throwing something on there and calling it good? I think we still aren't on the same page... i know id need to find a big turbo that would be efficient and have the highest flow rate at the 8-10psi i want to make my power at...you see what im saying? I dont want to run 25-30psi to make power i want to be able to make power at 8-10psi This is where we get off... the engine controls the cfm per boost level, NOT THE TURBO! A small turbo running 25-30psi will make more power than a bigger turbo running 8-10psi... Asside from some small pumping/spinning losses, at 8-10psi, a T25 will make the same power as the larger turbo, and the same CFM of airflow... I think you're confusing airflow with compressor speed... What I'm saying is... say you have a small turbo running 8psi at 600cfm... and you have a larger turbo also running 8psi on the same engine... what's the flow rate going to be? 600cfm. Mike Quote Link to comment Share on other sites More sharing options...
FastSE2DR Posted August 22, 2005 Author Report Share Posted August 22, 2005 why have i always been told 8psi is 8psi but the amount of air from each turbo will be different? Quote Link to comment Share on other sites More sharing options...
FastSE2DR Posted August 22, 2005 Author Report Share Posted August 22, 2005 heres what your saying to me...when i had my talon and had my stock 13g turbo on the car at 15psi and then i went to my 50 trim at 15psi and my car didnt gain any horsepower cause they are still pushing the same CFM? or if any HP just a little? How did i run 12s with the 50trim at 15psi and the 13g was MAYBE a high 14sec turbo... Quote Link to comment Share on other sites More sharing options...
bartonmd Posted August 22, 2005 Report Share Posted August 22, 2005 cfm per psi would be the same... BUT... the effeciency of the larger turbo is better (as long as you don't get too big on the turbo, where the exhaust has a hard time turning the turbine)... Those cars should have had the larger turbo from the factory because 15psi/redline is just barely at the top end of what that turbo can do, so they could get rid of the turbo lag on the bottom end... The air coming out of the stock turbo was also quite a bit hotter than the 13G... so, yes, your car makes more power with no other supporting mods except just the turbo because: 1. turbo isn't spinning as fast (effeciency goes up because you aren't adding so much back-pressure to spin the turbo faster, and you are putting the exhaust through a larger opening to boot) 2. Air coming from the turbo is cooler (effeciency goes up because cooler air is more dense) The air being cooler DOES mean that you can get more air oxygen, but the CFM is the same, the air is just more dense, so you get more O2... but it's still the same cubic feet per minute... My friend put a 16G on his 2G Talon, and it made a BIG difference because the factory turbo was so under-sized... the larger turbo is what SHOULD have come from the factory, and IMO, is ~ the "correct size" turbo for that application... Mike Quote Link to comment Share on other sites More sharing options...
bartonmd Posted August 22, 2005 Report Share Posted August 22, 2005 this thread should be an example for others too... we are having a difference of opinion, and have gone back and forth, what, 3-4 times, and nobody's called names, nobody's threatened to kick anybody's ass, nothing... Mike Quote Link to comment Share on other sites More sharing options...
FastSE2DR Posted August 23, 2005 Author Report Share Posted August 23, 2005 why when they list upgrades for do they list the turbos like this....16g 505cfm @15psi big 16g 530@15psi and EVOIII b16g 550cfm@15psi(those numbers were from my head idk if they are right or not)....? edit: this is on a subaru so this is food for thought about your not increasing CFM by upgrading the turbo....im definately not discrediting your ideas because i know they hold some truth but it dont think it goes as far as saying that i could make the same HP with a lot smaller turbo at the same boost level as, for example, a T67 Stock Turbo 360 CFM at 14.7 PSI T3 60 trim 400 CFM at 14.7 PSI IHI VF 24 423 CFM at 14.7 PSI STOCK HYBRID 430 CFM at 14.7 PSI IHI VF-22 435 CFM at 14.7 PSI SR 30 435 CFM at 14.7 PSI T04E 40 trim 460 CFM at 14.7 PSI Small 16G 505 CFM at 14.7 PSI PE 1820 510 CFM at 14.7 PSI Large 16G 550 CFM at 14.7 PSI SR 40 595 CFM at 14.7 PSI 18G 600 CFM at 14.7 PSI 20G 650 CFM at 14.7 PSI SR 50 710 CFM at 14.7 PSI GT-30 725 CFM at 14.7 PSI 60-1 725 CFM at 14.7 PSI GT-35R 820 CFM at 14.7 PSI T72 920 CFM at 14.7 PSI IHI VF 24 388 CFM at 18 PSI T3 60 trim 410 CFM at 20 PSI IHI VF-22 460 CFM at 18.0 PSI AVO 320HP 465 CFM at 17.5 PSI T04E 40 trim 465 CFM at 22 PSI Large 16G 470 CFM at 22 PSI SR 30 490 CFM at 22 PSI Small 16G 490 CFM at 22 PSI AVO 400HP 580 CFM at 17.5 PSI PE 1820 580 CFM at 22 PSI AVO 450HP 650 CFM at 20.0 PSI AVO 500HP 725 CFM at 23.0 PSI SR 50 770 CFM at 22 PSI GT-30 790 CFM at 22 PSI 60-1 800 CFM at 22 PSI GT-35R 880 CFM at 22 PSI T72 1000 CFM at 22 PSI my buddy is looking at a T72 for his 1.8liter integra GSR for next season. I believe he is running a T67 right now and just put down 540whp for a baseline run with it... Quote Link to comment Share on other sites More sharing options...
bartonmd Posted August 23, 2005 Report Share Posted August 23, 2005 I'm sorry, I may not have made myself clear, I said you will make more HP at higher boost with the smaller turbo than at lower boost with the bigger turbo... same boost levels for both would give you more power with the bigger turbo from what I said before... Also, I believe the turbos are marketed like that so that if you have supporting mods to the engine that allow more air flow (displacement increase or raising rev limiter for instance), and you want a turbo that can keep up with your engine, you can pick a bigger turbo for it... With turbos being waste-gated and NOT driven by any kind of pully, the turbo will only output the cfm that the engine will take at a given boost level. You have to think of an engine (at full throttle anyway) as a "positive displacement pump." It will only take in as much air and fuel at a given boost level as it can pack into the cylinders... The only way to pack more air into the cylinders at a given pressure is to make the cylinders bigger, so (in theory anyway), the only way to increase cfm or airflow is to either increase displacement OR to increase the rate at which you are spinning this positive displacement pump (rpm ceiling)... In reality though, you have to know that the 15psi is only at the intake manifold... Depending on the flow of the heads, the cylinders don't usually see that much pressure, so you can also increase your CFM per boots level by porting the heads and such so that the air can more easily make it to the cylinders... Headers and exhaust help in this too, as well as bigger valves and cam profiles... FWIW, it was a "big 16G" that my buddy had on his Talon... said something about it being clipped or something (vaines turned at the end or something)... He also believes that's the reason the turbo grenaded on him after maybe 10k miles... Mike Quote Link to comment Share on other sites More sharing options...
FastSE2DR Posted August 23, 2005 Author Report Share Posted August 23, 2005 that was the best explanation youve had yet...ill leave it at what you just said...i really liked that i think i will take that answer from you...see guys you can have an argument and not call names and swear...this was very good and you made me think a lot but your last post sums it up better than you said it before and it that makes sense to me whether or not your previous statements did...thanks for picking my brain...and in my defense the T67 was just something i pulled outta my ass...i didnt do any research or look around before i through something out...in the back of my mine i knew it was too big for what i wanted to do but i was more so defending the fact that I can use something big to make my power at 8-10psi without having to run 12+psi...in reality the project wont be happening soon, if at all...so it was just theoretical the 14b/16g series of turbos are kinda shitty anyway...they arent known to last very long...im assuming he was pushing it pretty hard and then it grenaded? Quote Link to comment Share on other sites More sharing options...
bartonmd Posted August 23, 2005 Report Share Posted August 23, 2005 You basically DOUBLED your power? My buddy with the Talon figured he was making ~325-350 horse and he was running 17psi with external BOV, header, 3" exhaust, and the Big 16G... (nevermind, deleted the post between our two I guess) In answer to your question, cooler air helps, but effeciency is most of it... The fact that the factory turbo is HORRIBLY inneficient (at the VERY edge of the usable range) definately helps in that comparison... If the factory had used a turbo more in the middle of it's usable range, you wouldn't see much power from going to a larger turbo, but they didn't... The other part is, maybe the factory turbo couldn't keep up at high rpm? I've seen some cars with under-sized turbos that make full boost by like 3500rpm, then it just drops off from there because the turbo can't keep up the airflow that the engine wants... so you're probably just making more power through more of the rev range with the larger turbo... I realise you aren't an idiot and would have researched it, but at the same time, one of my friends from college, he was a Nuc Eng... this guy knew EVERYTHING you could read out of a magazine, like what engines and parts were direct swaps, aftermarket parts, stuff like that, but didn't know how much of it ACTUALLY worked... I just didn't want you to buy this T67 or whatever from a friend hoping it'd work, doing the fab work and everything for it, and it turning to shit on you... that'd suck... Actually, the clipped Big 16G he had was clipped by an aftermarket company, and he thinks it wasn't balanced correctly (or at all) by them, which caused it to frag the bearing... Mike Quote Link to comment Share on other sites More sharing options...
FastSE2DR Posted August 23, 2005 Author Report Share Posted August 23, 2005 well the thing of it is with a 50trim i would lose power revving to redline because it would drop off because the manifold was maxed out at higher RPMs...my 13g had full boost at like 2k and it held prolly until about 6-6500...my 50 trim spooled any where between 3200-3800(gear mattered) and yeah i basically did double my power...i had to shift at about 6500 otherwise itd be slower... Quote Link to comment Share on other sites More sharing options...
bartonmd Posted August 23, 2005 Report Share Posted August 23, 2005 I'm mixed up... what was the stock turbo and what do you have now? Edit: Nevermind, it was on page 2... 13G = stock 50-trim = now Mike Quote Link to comment Share on other sites More sharing options...
bartonmd Posted August 23, 2005 Report Share Posted August 23, 2005 Also, is the doubled power dyno'd before and after, or is it seat of the pants? Quote Link to comment Share on other sites More sharing options...
FastSE2DR Posted August 23, 2005 Author Report Share Posted August 23, 2005 well not just by the seat of the pants but basically comparing 2 like cars and setups...and my motor was the mystery motor...it was way faster than it shoulda been...i know its not a true figure of power but its pretty reliable....and thats of course crank hp cause theres no way i was making 200whp with a 13g on an AWD car...and 400hp crank hp on pump gas is very feasible with a 50trim... Quote Link to comment Share on other sites More sharing options...
bartonmd Posted August 23, 2005 Report Share Posted August 23, 2005 you talking about a 50 trim on a completely otherwise stock engine? Also, did you have to upgrad the injectors and stuff when you switched to the 50-trim? Mike Quote Link to comment Share on other sites More sharing options...
FastSE2DR Posted August 23, 2005 Author Report Share Posted August 23, 2005 you talking about a 50 trim on a completely otherwise stock engine? Also, did you have to upgrad the injectors and stuff when you switched to the 50-trim? Mike well yeah just the supporting mods...in fact i went from absolutely zero exhaust...just off the turbo to a 3'' mandrel dp and 3'' PRESSBENT catback(which would be a restrictor over zero exhaust) cause my buddy sold it all to me for $200 and then its street legal here...i went from the stock 390s(it was an automatic motor, hence the 13g, 5spd motors are 14b's and 450s) to 680 injectors...and of course i upgrade the IC because the stock sidemount wasnt enough for the 50 trim...but it is all basically relative because a sidemount for a 13g is MORE than enough and the street core i used was just enough for the 50trim... my mods were just fuel related and i had a ported exhaust manifold and ported intake manifold with both turbos...but nothing done to the motor it was a drop in JDM automatic motor(which should have had smaller cams but people said it sounded cammed but im pretty sure it was all stock except the compression was a lot higher than it shoulda been thats why i call it the mystery motor) Quote Link to comment Share on other sites More sharing options...
bartonmd Posted August 24, 2005 Report Share Posted August 24, 2005 OK... that makes sense... My friend started out with a manual tranny, so he didn't get as big a jump when he switched to the bigger turbo and stuff (because his factory turbo wasn't AS undersized as the automatic tranny turbos)... plus the manifold porting probably didn't help the factory turbo all that much, but DEFINATELY helped the aftermarket turbo! Mike Quote Link to comment Share on other sites More sharing options...
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