I always thought the twins on the cosmo were smaller than the FD's, and they didn't make much power...(made for only what...6lbs of boost?)

I was looking on Pettit's website, and I saw his Banzai 3-rotor is making 550 HP @ 7500 RPM and 460 Lb-Ft @ 5500 RPM on 2 sequential turbochargers...

Is this possible on the cosmo stockers? Or is he using different twins (granted the only other sequentials I know of are the FD's, and I heard they won't fit at all onto a 20B...)??

 

non sequential stockers.

an FD has hitachi ht-12 i think and the cosmo has a 12 and 15.


someone correct me if i am wrong.

 

Yea one's larger, and one's smaller. I saw that on a thread yesterday. But the compressor wheels are smaller than the FD's from what I understand.

As for sequential or not, check out http://www.pettitracing.com/sections/Banzai.html
It's written in BOLD letters halfway down the page...SEQUENTIAL twins...so...??

 

They are REWORK'D stock twins

 

could you elaborate on that some?

 

Cosmo 20B uses HT10 and HT15.


-Ted

 

And Pettit uses...?

 

This starts to get tricky when you compare numbers between the JC & FD engines.

Despite what the specs say, the FD turbos are physically larger than the JC ones.

The front turbo on the JC is similar in size but the rear turbo is tiny compared to the FD

RE-Amemiya have done extensive tests on the 20B engine & found that 450hp is the max (reliable) power achievable with the limiting factor being turbo flow.

This is with 1-bar boost. Any more than that & these turbos will **** themselves in a matter of hours (of boost time..)

Seen it happen on a JC Cosmo with my own eyes & this guy was running just 1.2-bar of boost. Turbos spat the dummy & killed the engine within 500km of driving

 

At the risk of redundancy, that's pretty much what I thought...that you weren't going to be making more than 450 w/ the stockers. But Pettit's website clearly states/boasts 550HP with 2 sequential turbos...so he's gotta be using a different set of twins??

 

Would this be on a stock engine??? If the engine had a decent-sized port on it and there were clearance rotors, etc...it could probably hit 550hp @ the wheels. As far as what turbos they use, that is of question. I don't think 12.5lbs is that much for most turbos, is it?

Craig

 

Yea I would hope & expect that they did engine work...not just a swap.

I believe I read somewhere the Comso twins are only good/meant for something like 6 lbs...(remember the Cosmo was a luxury car). So 12.5 lbs would definitely be well out of their efficiency range, if what I read is correct...

 

The 550 HP is FLYWHEEL and it is as 14.7 PSI on a ported engine.

 

So it's making what...480 @ the wheels? And 14.7psi on the Cosmo stockers??

 

i believe the turbos are balanced ,blueprinted and ported, or some **** like that , ....with a good streetport and properly tunned engine ...yeah why not

 

Is it me, or every performance mod we do on the FDs seems to see the twins as the limiting factor?

On 13B-REW's, you can't make more than 400 on the twins...for more, ya gotta go single. On the 20B, you can't make more than 480 on the twins...for more, ya gotta go single.

What's the deal? Those of us who are suckers for twins just can't have our cake AND eat it too, can we??

I wonder how much work it would be (if it would work at all, at that) to try and fit the FD stocker twins on a 20B, and get some nice power out of it...??

 

Pettit claims they do something to the turbos. I believe it has been discussed quite often before.. Search, for I think someone previously posted some detailed information on them.

 

My bad...i'm BRAND SPANKIN NEW to the 20B forum. And after seeing (realistically) the costs, I'm probably leaving real soon too! lol. (I read it could be done for $15K, little did I realize that was for JUST the swap...)

I did search, and I came up with this...

And again Pettit's website clearly states 550hp on sequential twins...so all this conflicting info has left me scratching my head....(I can't believe we don't have a smiley for that!)

 

Well, i can answer one of your questions with this....




And since when is having a single turbo 20B NOT having your cake and eating it too!!!???

 

Fatty_FC3S, thanks for the icon lol. I dunno why I didn't see it...

Quote:

And since when is having a single turbo 20B NOT having your cake and eating it too!!!???

...When you're a hardcore sequential twins fan...

 

Whats the point of sequential twins? Meaning, why the desire?

 

No no. It was at 12.5psi...do you even know what engine/company I'm talking about???

 

What?

I am not sure what you are talking about, but I am talking about Cam's (Pettits) conversion. The 550 BHP is from their ported engine @ 1 bar of boost.

 

Awesome low end response...no large wait for spoolup, and of course, it being just so unique...

 

Yes... but a matched turbo to your porting will do the same; with higher top end HP. But, I guess you loose the "unique" thing your wanting.

In all honestly, I bet there are more 20b conversions with the twins than singles. Why? People can't afford to go all out after the conversion. The twins came with the package. A new turbo setup will cost them on average another 4-5k.

 

Yes, it'll give you the same if not more hp, and a lot more top end...but I still beleive you'd lose a nice bit of low end, and like you said, it's definitely not unique.

Don't get me wrong, if I wanted to make some unbelievable #s, I know a big single is the only way to go. But that's not my aim, and I just don't see singles as being anything special. It's the way that almost everyone takes...even kids in Neons and Civics.

As far as cost, I'm not worried about "extra" costs at all...seeing that I can't afford the 20B conversion done "right" as it is. Maybe in a couple of years...