tell me if i am wrong here?
This guy Tony at a shop her (AMS) has a hatch back with a GSR and a 14g turbo with IC. I was like why did you put such a small turbo on it, he says "because i did not want any turbo lag". (i tryed not to laugh!) he says "it will boost up to 18lbs." i tried to explain to him it dont matter how much you can boost if you can't move enought volume of air into the engine. he still did not get it, so i was like your engine is sucking air throught a straw!! then he goes on telling me someone told him "you dont need an external waste gate unless you plan on making over 400hp", what his friend failed to mention is that using an external wastegate and running it open loop you will make more horse power.

so what do you guys think? am i right?


[Modified by ATurboCivic2NV, 6:02 PM 3/20/2002]


[Modified by ATurboCivic2NV, 7:09 PM 3/26/2002]

 

You better hope so since you already gave him this info

 

he thinks i dont know anything any way cause i am white

 

If i am not mistaken the stock 1g eclipse (possible 2g also) come with a mitsu 14b. The 14g is bigger than the 14b. Now tell me how a 1.8L is going to not make decent power on a 14g when a stock 1g talon/eclipse will go 13's fairly easy on the stock 14b???? At 10 psi or so the turbo is perfect. At 18 psi it is deffinitely way out of the efficiency range. I bet it spikes to 18 psi and then falls to 12-15 psi at 8000 rpm. Right for low boost w/no lag. wrong for high boost.

 

are we talking about 2.0L eclipse engines? NO, we are talking about honda engines and our motors are not the same as a DSM motor.. We have greater CFM then them and our motors can suck in ALOT more air.. Therefore LETTING us use a bigger turbo, its a PRIVLEDGE our motors can support such big turbos that can PUSH so much air.. not taking advantage of that is ignorant.. Our motors will probably TOP out a stock eclipse turbo at 5k rpm..

 

that is what i am saying

 

How many cfm's does a stock b18 b/c put out????? I have done the math and I am sure I have a good idea. I do agree the honda b series engines do outflow the mitsu 2.L. But to say a b series will push the 14b much less 14g at 10 psi is just wrong. Sorry guys this is not going to happen. I will humble myself and apologize if the d16 project with a 14b i am doing cannot hold on to 11 psi. Will let you know. Just a little trust is all I need.


[Modified by lbz34, 11:07 AM 3/20/2002]

 

dont eclipses use the TD05-18G turbo, and isnt that the same exact turbo the greddy kit uses?

 

<U>STOCK</u>
1st Gen Eclipse = TD05-14B
2nd Gen Eclipse = T25

to my knowledge none of the Turbo Eclipses' come with stock TD05-18G turbos.

and I mention this in another thread. Mitsubishi makes the turbos used in the Greddy kit. BUT Greddy uses a smaller turbine on their kits, so the Greddy kits turbines are actually smaller than the standard turbine founf on Mitsu turbos.

 

Does anyone have CFM #s for either of the cars? I think that the 14G is fine, but I'd like to see the stats anyways.

 

you're wrong dude. It doesn't matter who makes the motor, a 1.8L@8000rpms will only flow X amount of air.

here is an example:
(using the cfm calculator http://velocity.websitegalaxy.com/cfm.html)
a 1.8L boosting 10psi would flow ~363cfm of air at 8000rpms
a 2.0L @10psi would flow ~353cfm@7000rpm, and 403cfm at 8K

furthermore, an eclipse will run 12psi stock, and ~16psi with a boost controller,
would would net
381cfm@12psi@7Krpms (STOCK BOOST) and 438cfm@16psi@7Krpms.
so as you can clearly see, the 2.0L is always going to flow more air than a 1.8L given the same boost level and rev limit.

A lot of people put HUGE turbo's on their small motors and run 7psi. That is just a waste of a turbo and you have so much lag. My turbo is a TD04-13G which is smaller than the TD05-14b (compressor AND exhaust housing), but I get full boost (all 17psi of it) at around 3500rpms on a 2L.

Anyway, a 13G starts to step off of the graph at ~400cfm (or higher than a 2.6PR in the midrange) and the 14b/g would be a little bit later, so you can see how that'd be a good street/strip (not strip) turbo for that car. For $100 used, it's a good bang for the buck, IMO. especially if you're running under 15psi and drive it everyday.
-C


[Modified by TypeC, 1:47 PM 3/20/2002]

 

All 1.8 liter engines are not equal. You must take into account head design, chamber shape, compression ratio, etc. Those cfm calculators are good for baseline info, but not much more. Oh, and there is a benefit to running lower boost as opposed to high boost...less heat gain.

And to add, I don't think there is a right and a wrong answer here. It depends on the application. Street cars will usually be set up with a smaller turbo for decreased lag. Yes, you CAN run higher boost levels, but you will get added heat. Strip cars will generally run a larger turbo since lag isn't really a concern.

I say we're all correct


[Modified by DSF, 2:54 PM 3/20/2002]

 

right. The effeciency of the head/motor, etc will change the numbers, but not by much. to get raw potential flow numbers, diplacement, boost, and rpm is all that matters. The point is, saying just because it's Honda the 1.8L at 5K will out flow a 2L at 7K is just plain wrong and arogant.

 

TypeC, I am not wrong.. like DSF said, there are more things u have to take into consideration then just displacement and RPM.. heat, efficiency, cam design, even rod/stroke ratio and compression, vavle size etc etc..

I big turbo on low boost is not a waste, thats like saying vtec is a waste "you have to wait till 6krpm to get power" now thats what i call lag.. We all know big turbos, make the same power as small ones with half the boost, but they have lag.. Now when you are drag racing do u really experience lag? I launch at 4k in 1st gear, essentially skipping the lag and jumping right into the power band, lag does not seem to exist.. The only time I experience lag, is when im cruising in 4th at 2k RPMs and floor it but I could just *downshift* and lag would be eliminated.. with the short gearing in our hondas lag doesnt really matter because we can always put the car in the powerband when power is needed..





[Modified by DIRep972, 8:20 PM 3/20/2002]

 

Lets not forget

TDO5h-14b 1gDSM 5speed (Turbo) flows at 405cfm @15psi
T-25 = 2g DSM 5speed/Auto flows around 360cfm @ 15psi

Now a Td05-14g 6cm housing flows at 465cfm @ 15psi

This turbo would be great on a GSR.. here is the compressor map



btw, you guys ever see what a DSM head even looks like? their intake ports are about twice the size of a honda. Very nice design

Jeff Frank http://www.homemadeturbo.com

 

I didnt say the honda 1.8L will out flow the DSM 2L at 5k RPM.. I just said that a GSR motor will out flow the DSM 2L because of more factors that have to be taken into consideration..

there are just too many factors to make the comparison.. and all we are doing is comparing graphs, and making guesses.. The only way to really find out is to put the turbos on the two different motors and dyno them..



[Modified by DIRep972, 8:18 PM 3/20/2002]

 

and what exactly is "CFM" again?

 

when I say top out I mean the turbo falls out of its effeciency range and begins to work too hard to keep up with the motor.. In which, it does the same on the DSM's.. I didnt say this turbo was good for a DSM either..

Why do they upgrade to bigger turbo's? to make more power because the stock one is to small..

 

I fully agree with him I have better success with a 16g internal wastegate with all my turbo kits and the minimum boost on the wastegate is 11psi and 16g turbos i use flow 550cfm. Max constant boost on this turbo is 25 psi and there is little to no lag on these babys 16g turbos in DSM have been known to run 11's in the 1/4. Garret turbos in normal kit will never ever see there max boost bolted on a B16a and have lag due to the big compressor wheels it has. External wastegates have no disadvantages but why, it takes extra plumbing and sometimes a pain to deal with. Advantage though is its adjustability with springs. Its a plus but really not needed until you get tons of boost. Then having a wastegate is justifiable. Civic kits generally come with external wastegates because garret doesnt exactly make a turbo with an internal wastegate in mass. I for one have used both they do the same thing boost but he does have an advantage fast spool and he would never use the max boost on this turbo running 11-20 psi. oh yeah and mitsubish 95-98 come with 12c turbo is turbo runs a spike boost of 18psi and 14psi max constant. and 91-94 comes with a 14b which runs a 23 psi spike and 18 psi constant. 16g come on starions and japspec motors.

"Just dont stand there Boost something"

 

you said:
and
which are both wrong. boost for boost (same turbo, dp, intake manifold aside), the 2.0L DSM will always flow more air than the 1.8 (given the same redline). That's all I'm saying. A DSM will always have more flow potential. I mean, the other factors DO matter, especially for power, but the physics don't change. a 2L will ALWAYS flow more than a 1.8L all things equal. That's all I was saying/correcting.

peace,

-C


[Modified by TypeC, 2:51 PM 3/20/2002]

 

also, you're right. For racing, lag isn't really an issue (unless you have a T78 on a 1.5L ).

 

Actually If you go on a lot of other car forums (DSM, RX7, Supra etc) and do a search for VOLUMETRIC EFFICIENCY there is usually a few discussions. And in a lot of those discussions a lot of people agree that Honda VTEC's have one of the highest VE percentiles. And a higher VE = a higher CFM so a 1.8L with a high VE will "out-flow" a 2.0L with a low VE at the same RPM.

Say for example the S2000 (2.0L VTEC)
it has a max VE of 112% at 8000 RPM
CFM = (cid * rpm * ve * 0.5) / 1728
(122 * 8000 * 1.12 * 0.5) / 1728 = 316 CFM

The point I'm getting at is pretty much a 2.0L VTEC will flow more than a 2.0L NON-VTEC. &lt;-- you can also substitute VTEC for whatever variable valve mechanism you want but usually the variable-type engine (ie. VTEC) will flow more CFM.

I definately know this is true of Honda's VTEC system, not so sure about VVTLI, VANOS or the like.

But like you said TYPEC, all things being equal a 2.0L will flow more than 1.8L at the same RPM. HOWEVER we comparing a 1.8L VTEC with a 2.0L DSM, I was anyways. and to make it equal I assumed that the 2.0L Eclipse was running zero boost. So the all things equal statement goes out the door.

Now If you want to try and figure out the CFM of a DSM at XX amount of PSI, I'll do my own number crunching and see what we come up with for a B18C1. Only thing is you have to figure out the DSM's CFM with no boost. all this is just for arguments sake, find the peak VE% of the DSM and the RPM at peak VE%.

we already know that VTEC engines have higher than normal VE% so I'll say that a B18C1 has 100% @ 7600, since both the H22 and S2K have 102% and 112% respectively and both occuring at around peak HP.

<U>B18C1 @ 7600 RPM</U>
(109.8 * 7600 * 1.00 * 0.5) / 1728 = 241.45 CFM
Now if this was with 10 PSI of boost...
241.45 * 1.68 = 405.64 CFM


[Modified by BlueShadow, 9:16 PM 3/20/2002]

 

Cold Fusion Markup?

-ryan

 

Cubic Feet per Minute

how much air is flowing into a cubic foot uhh per minute...

 

all i have to say is this

to say that displacement is the only factor to determining how much air an engine flows is silly. yes all things being equal a 2.0 will outflow a 1.8 but you have to factor in compression ratio. if you take 2 engines one being a 7:1 cr 2.0l engine (dsm) and compare it to a 10:1 cr 1.8l (b18c) it is not unreasonable to think that the 1.8l can flow more.