Hey everyone this is my first post on this board, Ive been lurking for a long time tho. I think this is the best FI forum out there, I have learned alot from you guys/gals. I was wondering how to read a compressor map. I currently have a basic LS/VTEC in a 90 teg, but I have a spare b18 block in my garage that Im slowly getting parts to rebuild/strengthen. Im going to have it resleeved to 84.5 mm bore ala GEM. I already have a Z-dyne secu,z-10 girdle,ITR oil and h2o pump,clutchmasters flywheel,j&s original safe guard,msd sci and all the goodies that go with it. I need to know how to size a turbo for a 2.0 LS/VTEC (b16a head) for after the block is built. TIA

Aron

 

in my opinion those compressor maps a pretty useless. if totally relied on those maps there are a lot of combinations that are proven to work in the real world that would ahve never been tried.

It really depends on how much hp you intend to make. I don't run turbonectics turbos, but something similar to what I like is their 60-1/T3. The turbo we're planning to run on one of our street cars is a custom unit that is supposed to be very responsive, yet it will make an honest 500-550 hp to the wheels. It looks very similar to the turbo Geoff runs on the maxrev kits. (4 bolt symetrical t3 ex)

 

Actually compressor maps aren't entirely useless, but I do agreee that there are many variables you have to account for such as the presence of an intercooler, IC efficiency. IMO though to be able to select a proper turbo ou need to know the following info about your engine.

-engine size in Liters (bore and stroke will help too but not necessary)
-engine redline
-the volumetric efficiency at certain RPM points
-how much boost (PSI) you want to run

EDIT: here is a link that shows you the basics of selecting a compressor map. Dont pay to much attention to where I'm trying to select fuel injectors, its still unconfirmed what I posted about the injectors.
http://www.preludeonline.com/showthr...threadid=37524



[Modified by BlueShadow, 4:59 AM 1/27/2002]

 

I don't think anyone beside maybe an actual honda engineer can convince me they actually know the volumetric efficiency of a given honda motor. I will continue to say the the maps are pretty useless, mainly because there is a lot of techical information (including maps) that are not published to the public. the turbos i run are custom and because of that the maps aren't readily available, and comparing it to what's on the internet is pointless. I've calculated turbo size using compressor maps before and I think its not very far from plain guessing. The honest truth is that in the real world it all comes down to trial and error.

 

Ok that helps out a little. My goal is to get 350-400 whp out of a 2.0l sleeved LS/V. It is my daily driver and I want to keep the compression to about 9:1 and rev to 8-8.5K. Basically, what turbo wheel trim, a/r would you reccomend. I dont want to go over 15 psi if I dont have to. Bill at z-dyne said that if I use the 3 bar. map sensor that Ill lose some resolution tuning wise. Ive seen some dyno plots of some members on the board that are making the kinda power that I want but they dont have their specs listed. As far as trial and error that would be very expensive for me as I live in Nebraska and cant source all the parts very easy. Your help is very appriciated.

Thanks,
Aron

 

thats about the only thing thats hard to figure out for our motors. I didn't say it was easy to find out, but it is necessary if you want to do the math and do it right. when I have to use a VE though, I use the highest % for the redline and a lower % for the start of VTEC. I use 95% for my "high VE" and 80% for my "low VE"

Maps arent entirely useless though, but I agree that there are to many variables that you have to figure into selecting a turbo (IC, IC piping, air filter, DP size, wastegate type, etc).

 

another reason why people dont like to do the trial and error method.

 

well, i wasn't implying that you should do the trial and error yourself. more like ask someone (tuner) what would fit your needs. I think Import Builders & Sgt is making the hp you want at those boost levels, maybe you should email them to see if you can buy that turbo from them. But I don't think what your asking for is something easily attained. for that kind of performance I would think you'd need a very efficient ic, turbo manifold, turbo, head, and near 10:1 compression.

Your goals are pretty similar to what we're looking for on our street car, but we haven't ran it on the dyno yet, so I can't give you a solid reccomendation on the turbo we're running.

Also, I wouldn't worry too hard about losing resolution using a 3 bar. what's a bigger concern is at upper boost levels you get close to the detonation threasholds for pump gas which is anywhere from 18-20 psi.

 

Cool Ill email importbuilders and see what they have to say.

As far as detonation I can get 93 octane gas around here and I also have the j&s original for some added safety. So I think that I could boost pretty high pretty safely.

Do you plan on dynoing your street set up any time soon? I would really like to see it. What is your basic set up ie ..engine,head ect...??

 

hey tegman2,

when you e-mail importbuilders ask them if a T04E 60" compressor and a T3 .62 or maybe a .82 A/R stage 3 will work ok for you? I always tell people to get a second opinion when I help them with something like this. I also want to know how far off my calculations are, and If importbuilders suggests a different size could you find out why? so that I can make corrections to my math and stuff.

I was doing some math on your specs, But I dont how accurate this is. I think to be able to push 380-400 HP at the Flywheel you'll have to run at least 15 PSI. I'm assuming that with your hybrid engine you'd be pushing 190 HP at the crank. so your basically doubling your HP. so I'm thinking that you would have double the HP so I doubled the airflow rate.

to sum it up, I figured to be able to push 380-400 HP to the Flywheel youd have to be at about 14-15 PSI, maybe more. thats just my opinion though, someone might have a better answer than that. A lot of my info is gotten from simple extrapolation. without any firm info I make do with the bits of info I have, which is a lot better than a WAG (wild a$$ guess). But then again I could be wrong.

 

might wanna check out this post.

12lbs on CRVTEC (same as 84mm LSVTEC) = 372whp
https://honda-tech.com/zerothread?id=104324

 

Yea, I read that post but they dont list the turbo specs... But that is very impressive though.

 

Hey BlueShadow,
Import builders said any T4 with a 4" inlet. Thats all they said.

 

I'm not exactly sure what you're looking for but...try this post out.. https://honda-tech.com/zerothread?id=121021

 

http://www.turbofast.com.au/turbomap.html

 

The link is good reading, but there are a lot of turbos aren't listed by that site, so take it for what it is.

 

I remember when I was first doing everything by pencil and paper, eventually someone showed me that link. All I can say is that my numbers always come out the same as the turbocalculators. My numbers aren't off byt very much, usually my numbers are off by no more than 5-10 lbs per minute +/-. I still use that site to cross-reference my own numbers though.