I've been doing some searching today and haven't seen anyone talk about running e85. e85 is a big thing in the dsm community and I thought it strange that it's not talked about much here, especially since I saw that people run boost with no intercoolers on pump gas!

Anyway I still don't think I've found an answer as to how much boost the motors can take IF PROPERLY TUNED. Everyone talks about putting holes in pistons but this is only due to a poor tune.

I'm thinking about doing a cheap man's turbo build using e85 with no intercooler. DSM turbo stuff (I still have all my stock stuff), bigger fuel pump, my old 550cc injectors, slap an safc on there and run e85.

Only thing I'm wondering is the strength of the bottom end/headstuds. A dsm wastegate spring pressure is 9psi, so I don't want to run that if the motor can't take it.

I don't want to do any motor work with this car, just a simple boosted setup for my dd, but anyway e85 would make the tune safe enough for me to do it for well under $150 since I have all the main parts already.

 

hmm there are plenty of turbo 3gens. you are just in the wrong place. head over to prelude|power.com and you will find plenty.
and everyone knows e85, but it is just a fuel, how much can you talk about it really.

the engines have a very long rod ratio and it eats them up. i just would not keep stock rods with the engine.
i don't understand how much you talk about bad vs proper tuning then say you want to 'slap' on an afc. i would highly recommend converting to OBD1 and doing a real tune.

 

Thanks for the advice but I also posted on prelude.power and still didn't get answers.

Saying that e85 is "just a fuel" is quite the understatement. Many big shops are now realizing that e85 will actually produce more horsepower than race gas. Even though e85 has a lower octane than 110 or 116, it's cooling properties completely take over at that level of boost/amount of fuel in the cylinders.

And to talk about proper tuning and how many don't do it. I myself didn't say that I would do it the best way, because I don't want to/have that kind of cash to drop on a dd. I did however say that the way I would do it would be extremely superior to the guys running pump gas with no IC or meth/water injection. e85 will allow you to have such a sloppy tune and still not blow anything up or hurt performance. It has a much wider power range A/F wise than gasoline ever will. Also e85 burns most efficiently with advanced ignition timing, so there's another plus that will yield more power.

I could go on and on about how special e85 is, but that's not the info I'm seeking or trying to distribute. I'm looking for info like the following: A bone stock dsm 6bolt motor can withstand 27-33psi of boost with the proper tune and supporting mods. - That's 100% true by the way!

Thanks for telling me about the stock rods, since you're the only one who's given me info so far concerning the limits of the motor it appears that the rods will be my weak point, since they're not a factor that you can "tune" out.

I look forward for ANY more advice on the kind of abuse these motors can handle.

 

I would check into the fuel requirements of what you want to do, you need 30% more of e85 as you would gas for a comparable power level, I don't know if your 550's would be enough.

 

Contrary to popular belief it's actually closer to 49%, it's just that you can tune wot to be quite a bit leaner without blowing anything up.

Stock injectors are 290cc right? Also do you know what base fuel pressure is?

 

E85 education?
Hmmm.......
When I SEARCHED I got 250 posts with e85.
https://honda-tech.com/search.php?searchid=5048719

 

Aaaaand how many of those have to do with the b20a5?

None.

Usually people don't run it unless they're really making some ponies. I want to run it because I already have the parts, e85 stations are nearby, and I don't want to have a perfect tune or fear blowing my motor.

I know how to search and I understand your post, we get newbs all the time on the dsm forums who just spout out questions without looking anything up, and quite frankly it gets downright annoying. That's not what I'm trying to do, I can search and search and search, but truth is there isn't much info on the b20a5, so that's why I'm posting all my questions here.

So again, stock injector size and base fuel pressure anyone? I didn't see these specs in the vfaq anywhere.

 

E85 an NOT a perfect tune? Why bother? W/o tuning you probably will blow your motor.
E85 with stock injectors? Impossible.
I'd be shocked if the stock injectors are over 250cc.

 

::sigh:: That's the whole reason why I'm wanting to use e85, you can botch a tune and still be safe.

I said I have 550cc injectors from when I upgraded to 750s in my dsm, which is also about to be running e85, although I have to bump my base fuel pressure up a bit to get a little more out of the injectors.


EDIT: I just need some freaking facts and specs on these motors people, I don't need help telling me how to boost a car or how turbo and detonation and tuning works, I've already learned all that and been in that game for awhile. I just don't know jack about this motor and it's turning out to be pretty hard to get any info on the b20a5, so if you have any, or have any stories of what other people have done on the stock internals, let me know please. Thanks

Brad

 

No such thing as "SAFE" when referring to a motor.....

550s will be enough......

 

I'm sure they will be but I can't calculate anything on the safc until I find out stock injector size, stock fuel pressure, and fuel pressure after I upgrade my fuel pump.

 

other than the ludes and the lean burn civics (all i know anyway) honda injectors are all 240cc.
pressure is 35-41 w/o vacuum

edit :found this https://honda-tech.com/forums/honda-prelude-4/injector-ccs-question-2570285/
no clue if it is all accurate, but 240 other than the special cases is the accepted number i've always seen for the past decade.

 

Thanks for the info Night! You've been the most help so far. It looks like 550s would be far too large as I would have to advance the ignition timing quite a bit, e85 burns better with a bit of advanced timing but I don't want to go over the top since I'm not sure what these motors are capable of.

It looks like you could drop in 360s and run e85 without changing the tune at all, you'd probably be a little rich but not so much that the ecu couldn't handle it in the fuel trims. I'll probably put in some 450s that I have laying around so that I can advance the timing a bit and get a better burn.

 

I mean, isn't a big advantage of E85 being able to throw more timing at it?
I can't see using E85 without ignition control and just an safc.....
Almost seems like you're Anti-Tuning.....and trying to figure out ways to do this cheap.
Fast Cheap Reliable----Pick 2. But you already knew that coming from DSMs

 

Yeah advancing the timing is a big advantage, and getting larger injectors than you need (pulling airflow out with the safc) will automatically place you on a higher timing map, so my timing will automatically be raised. Using 550s might push the timing higher than I want with this motor, I'm not sure yet though because it seems there's no info for this motor, maybe someone else can contribute something I need.


As far as the saying, "fast, cheap, reliable.." goes, I HAD less than $500 invested (besides normal maintenance) in the dizzum and could keep up with stock evo's, also I drove it about 50 miles everyday.

So the saying doesn't apply as long as you know what you're doing, unfortunately most people don't do their research first.

And NirVTEC, it really seems that you're just coming in this thread trying to bash, and I don't understand why. I'm trying to do something that could potentially help the community, and show people that it doesn't take $1500 to boost a car safely and reliably. So I ask you, if you can't help contribute or unless you have serious questions of your own please don't post in this thread anymore.

I know you've been a member on this site for quite some time and I'm just a newb but I'm not new to cars, turbo-charging theory, fluid dynamics, fuel and timing, e85 or anything else. The only area I really lack in is suspension. So please stop treating me like a teenager with a new ride.

 

Enjoy! The B20a5 is such an inferior motor to a 4g63 that you may want to buy a back up engine just to have......Being that you seem to NOT want to tune, maybe buy 2 more.
There will be nothing safe about a junkyard turbo setup on a B20...
People have been boosting this engine for 15yrs, I'm sure you can dig around and find a nice 2/3gen board to get some real answers. I do remember 1 thing that stands out from the owner of Hondaprelude,com He had an issue with a power steering line that eventually melted and started a fire. Something you may want to pay attention to when you do your install.
IIRC you can use Turbo Edit and/or Mega-Squirt for tuning

Bashing: Its the Honda-Tech way...don't take it personal.

 

Yeah I already pulled the PS and AC to get the engine bay cleaned up, looks 10x better with all that crap out of there.

 

I can attest to that.
Ditch the cruise also, relocate battery.

 

Cruise is in the works, battery might stay up front I'm not sure yet. Quick question about the cruise though: It looks like I can just cut the cable at the firewall and yank it out, is that right? The dsm cruise is much different and you have to get an throttle cable from a car without cruise so this one is pretty foreign to me.

 

Not sure on 3rd gens. On my 4th gen, I just disconnected everything, didn't need to use anything from another car.
There should be some "carry-over" parts from later 80s Accord if you need stuff.