Was wondering if anyone has a dyno run of a stock port twin turbo 20B.

 

Stock 70,000km C-series 20B in a JC Cosmo.
https://www.rx7club.com/attachment.p...postid=1819419

Stock-port 20B with non-sequential turbos, standalone EMS, upgraded ignition, FMIC, in an FC RX-7 built and tuned by a professional.
http://www.cris.com/~Asam/Dyno1.html

 

2psi worth 35 hp? cool

 

No that's 14psi not 12. The stock twins are running way out of their efficiency range. Notice how the hp drops off so early.

 

You're right about the "way out of their efficiency range". Compared to the stock 5.5 psi, 1 bar (14.7 psi) is demanding effort way above the design parameters. However, the abrupt drop-off at 6200 was due to a faulty blow-off valve. I haven't had a new dyno run since the valve was replaced, but the drop-off in boost is now more gradual. Based on the horsepower and torque curves at 10 psi, I assume that peak horsepower is now higher, but I won't claim that until it's proven.

 

ahhhh, thought it was 10 and 12...my bad.

i wanna call my turbo guy and see what he can do with the stockers....maybe hybridize them.
rez wants to keep his turbos sequential, but we're looking for at least mid 400's.

ya think bnr would hybrid the smaller turbo like they do with the fd's?

 

I believe BNR does offer an alternative to the small stock turbo on the 20B. I was thinking about getting one at one time, however, when I was talking to the guys at PFS about it, they said that the BNR turbos that they had seen in the shop on customers' cars had oil leaks. Also, the upgraded turbos tended to spool up more slowly than stock, due to the increased mass of the larger impellers.

Not trying to start a p!ssing contest, just offering a little info.

As I understand it, Cam Worth at Pettit uses a modified 2nd gen turbo with good results.

 

since we're keeping it sequential, i don't think we'll have any spoolup problems. it's a big streetport anyway.

is there any way to get some info on using the modded 2nd gen turbo? i've got a few of those laying around.

thanks

 

Call Pettit and talk with Cam. http://www.pettitracing.com/flash.htm The RX-7 link is in the upper right hand corner.

Tech support: (561) 844-2258
Sales: (954) 563-6064

He may tell you what to do, though he is more likely to offer to do it for you, for a fee.

If memory serves me right, the housing was reamed out and a slightly larger impeller was put in it.

 

You do understand to run the twins seq requires you to use the stock ecu right?


IMO running the twins seq isn't necessary if the 20b is installed in the Rx7. The Rx7 is nearly 600 lbs lighter than the Cosmo. Trust me there is plenty of torque available in the lower rpm's with the twins running non seq. Check out this dyno chart here:





This is a fresh rebuilt 20b with the twins running non seq. This run was done during the break-in and at 6psi. Look at how much torque is available at and below 3K. A 13b could only dream of putting down a power band like that! Also this engine has a conservative street port too.

 

They can be sequenced through a standalone EMS, but it's a lot of work.

 

you could also wire up a stock fd ecu to just get and rpm signal and switch the turbos over.

 

we'll use the ems.

 

That may not be necessary. The new Wolf 3D 4.0 can run the FD turbos sequentially, and it appears as though Pettit is now using the Wolf to enable sequential turbo operation on their 20B-REW Banzai. I would imagine that several other EMS's could do the same if somebody took the time to figure it out. The budget EMS has come a long way since the 90's.

 

Most can run them sequential. It just requires PWM options and some various relay works. With the old Haltech E6K, I ran my turbos sequential from that. I was able to choose when the turbo actually came online. It was pretty neat.

 

It may appear to be set-up sequentially but, I don't think David's car is.

 

its really only 3 outputs, its just getting the timing right thats the trick.

if you're bored look up the non sequential switch, it turns the sequentials on and off

 

eh, settin' up sequentials isn't that hard.

 

then how do you do it? I've never heard of people running sequentials with an aftermarket ECU.
Does anyone have some more information or threads about this?