I always hear so much hype about how the 20B swap is the *ultimate* way to go...and it's much more reliable, (esp. given the power ppl are trying to make outta them, as compared to the 13B-REW) etc etc. But I'm real curious as to whether anyone's blown their 20B and had to rebuild or replace it yet? And if so, what were the circumstances that led to the failure? I haven't read of it happening even once (yet)...but that doesn't necessarily means that it's not happening...

So if you would be so kind...

If you had to rebuild/replace your 20B:
- What kind of strain were you placing on the engine? (hp & turbo setup)?
- What caused it to fail?
- How many miles did you have on it?
- How hard/expensive was it to repair/replace it, given that the 20B and its replacement parts are a lot rarer than 13B-REW's?

Thanks
~Ramy

EDIT: Mods, plz leave this thread here...don't move it to the 20B section. There isn't that much traffic there, and I'm trying to get the most info I can. After all, it IS 3rd gen related

 

How is this 3rd gen related? I've heard, don't have first hand experience with this but i've been told by a Japanese friend of mine that it's not safe to rev the 20b very high, like over 8K. You get to much e-shaft flex. He was also saying for reliability not to boost over 14.7psi. He said the best setup for a 20b is greddy t88 turbine boosting 14.7psi on a stock motor. Other than that it's not any more or any less reliable than a 13b. All the same stuff applies.

-Destin

 

Uhh...cuz I'm not talking about your experience driving a Cosmo... I'm talking about a 20B swap into a 3rd gen.

Whaa? Are you serious? The revving...I dunno if anyone's takin their 20B to 9K rpm and what not, so I dunno how big a concern that is. As for e-shaft flex, I take it most ppl use the e-shaft that comes w/ the 20B (as opposed to an upgraded one?)

And see...I'd venture to guess most ppl running a 20B are definitely boosting more than 15psi, and a cpl of ppl have porting done as well. I'd imagine that if it was "as reliable" as the 13B, then we'd hear of people blowing apex seals left and right, no? Cuz I believe there definitely is a fair amount of ppl w/ 20B swaps out there...

 

The 20b is just a "no replacement for dispacement" excercize. You can make 500 horsepower running alot of boost through your 13b, or you can make the same running moderate boost through your 20b, and hopefully benefit from a reliability/longevity standpoint in that you're running less boost, creating less heat in the process, and not pushing the motor as hard.

That said, if it isn't tuned right, runs lean, overheats, etc. it'll pop just like a 13b, and you'll be replacing 50% more shtuff to get it running again.

and as far as e-shaft twist, i wouldn't worry about revving either you 13b, or your 20b, or a a 4-rotor for that matter to 9k rpm if you're worried about the above.

 

He doesnt have a cosmo, even if he did-it would be the same. the motor performs the same no matter what car its in. boost is boost whether its installed in a cosmo or an FD

yea, hes talking about the stock E-shaft. it is prone to flexing, which isnt good. generally speaking, the 20B puts more power and torque per pound of boost than a 13b would. hence, the reliability factor is greatened because you dont have to run as much boost through it to get decent power.

 

I understand that...the reason for my comment was he asked how it was 3rd gen related. That, and while boost is boost, 6psi or 10psi on the wimpy stock Cosmo twins is nothing compared to a ported 20B w/ a T78 pushing 22psi. And THAT'S the kind of setup I'm curious as to it's longevity...not the stock form, but the modified form in a 3rd gen - because, after all, don't think that the 20B will take the same kind of punishment (ie be subjected to the same type of driving) in a Cosmo as it would in an FD. So I think that's definitely an important factor.

Ptrhahn pretty much said the same thing. And I totally understand and agree w/ that point...you can produce that much more power from the engine, thereby allowing you to run less boost and stress the engine & turbos less. BUT, taking that into consideration, I would STILL expect to hear of a blown 20B here or there, but to date I haven't yet. Obviously the limits are pushed up a bit. E.g., if the 13B's reliability drops markedly at the 400rwhp mark, the 20B's reliability drops markedly at say, the 550rwhp mark (these #s are for illustration, and not for accuracy's sake). Yet I'm sure there are a # of people running more than 500+ hp on their 20Bs, and still we have yet to hear of one needing a rebuild.

I'm thinking either a) their upper limit is much higher (eg. 700hp, etc, where very few ppl actually run them), or b) people just aren't mentioning that they needed a rebuild??

EDIT: oh and moderators...thanks for moving the thread 38 views?? This thread would have had a MUCH better chance if it was left in the 3rd gen section...

 

Do you know how many 20B owners visit the 3rd gen section, let alone have a 20B in an FD? And out of those, how many have had a 20B long enough to need a rebuild?

A 20B is a 20B no matter what car it's sitting in. You'll get a lot more help from the FC 20B guys as there are more of them that have done the swap on this forum (and this is where they are at).

It's not the amount of views you get, it's the quality of replies which what you'll get here.

 

Im sorry Mahjik I figured just w/ the sheer # of ppl in the 3rd gen section, the probability of getting answers would be greater...that's all. If not 20B owners themselves, then from them knowing someone who does have a 20B.

You make a very good point at how many people have had a 20B long enough to need a rebuilt. But then again, ppl have blown 13B's in under a year or two lol.

FC 20B is more common you say? Wow...that's news to me. Any reason why? Is it an easier swap?

Words from the wise hehe I guess I should thank you for moving the thread...

 

I believe Derrek berg in TX blew his, or had to replace it. Not sure the cause, but he now has a motor built by Acosta.

 

are there fixes to the shaft flexs in the 20b or is it one of the things you have to deal with?

 

I think the flex issue is over-rated.

 

The e-shaft flex is something i've only heard from one Japanese guy. I've never read about it or heard anyone else talking about it.

Well there aern't near as many 20b's as compared to 13b's. Also I think the amount of money it costs to put a 20b into a car has some to do with it also. Your regular Joe isn't likely to just have a 20b in his car and not know anything about it. But when it comes down to it there is 0 difference in the apex seals except for some are 2 piece and 3 piece. The apex seal sits on the rotor the same and see's the same conditions in each motor.

-Destin

 

Derrick had to have his motor rebuilt because it twist'd and jamm'd the seals,he sent it to Acosta to have it pinn'd, that's what he told me anyway.

 

I'd think the same...who's gonna be taking the 20B higher than 8K rpm?

Twisted and jammed the seals? In English, that means...? How'd that happen? And anyone know what the word is on Acostas? I saw them w/ their 20B RX8 at Rotorfest...looks like they know what they're doin.

 

You should be trying to weed out the "I know a guy who has a 20B and..." responses.. It's best to get your info straight from the source as info tends to get twisted after it's being told through 3rd person. I agree seek the FC guys, some have had 20B's in their cars for years although I believe most with stock twins. As far as more reliability it's because the motor has a bigger displacement, so you're not stressing it as hard to get the same amount of hp out of a 13b. I don't think it's that the motor is any different than a 13b(besides the obvious difference). I would hardly believe a 20b to be "bulletproof" in any way vs. a 13b. So I would have to agree with Destin, same rules should apply as 13b.

 

What made the motor twist? Did the e-shaft flex? Rev to high? Or was it a motor with an early serial #?

-Destin

 

While ideally that's definitely the way to go, just as I anticipated, there's practically no reports or records of 20B's going bye-bye. While entertaining 2nd hand info may very well invite not-so-accurate info, I think it would still give a partial picture of how many ppl have had to rebuild theirs...(vs. no picture at all), you feel me? Cuz a blown engine is a blown engine. Who what where and why may not be right on, but that can be narrowed down and verified...

Oh and on the real...another point I was thinking about is, seeing that the 20B swap is THE ULTIMATE mod on the FD, taking that into consideration, along w/ it's prohibitive cost, how likely do you think ppl will willingly step forward and say "hey, yea $35K later, I blew my motor! lol

 

From what I remember he has a early series motor, I don't think his had any e-shaft flex, you can PM him his forum name is rxman720b

 

John, I've heard someone mention this before...early vs. late series 20B motor. Could ya clarify what the difference is?

Thanks
~Ramy

 

the only difference between the early motors and the later ones is strength of the irons
around the pins.
one of the 20b's that i have was a blown motor when i got it and it was the center
rotor and housing that was bad.
lance of 3 rotor.com when he blew his motor took out the center housing and rotor as
well. seems that the center is where they fail, i have heard of a couple others that failed
in the same way.

 

another thought, but after 500-550 hp you start to have MAJOR trouble putting it to the ground.

anyone remember the thread where RED-RX7 was racing a viper and went sideways in 4th gear?

seems to me like 700 hp would be useless in a <3000lb vehicle and 4.1 gearing


my point is that people just dont make a lot of power b/c all it would be good for is bragging

 

Does the iron around the pins have anything to do w/ the middle rotor going bad? Or are they two totally different things?

Oh and Swolbynos, very true. I'd be VERY happy w/ 500 to the wheels

 

The 20b Cosmo I bought that was 100% stock let the #3 rotor go. I bought it with a bad motor, took it out and found out it was the #3 when I opened it up. The rotors had layers of carbon on them. The #3 rotor and housing where in very bad condition. The engine had just over 100,000klm on it.

-Destin

 

wow 100,000 is a great life!
matt

 

It just goes to show that 20b's are susceptible to the same problems as their 13b brothers. layers of carbon meaning the engine was babied and not driven "properly" . a chunk of carbon prolly let go and killed the rear housings...100,000 km is only about 60,000 miles. that sucks