Hi guys,

last saturday dynoed the Rx-8 with SFR custom turbo kit with HKS F-CON V PRO standalone and we got some issues, the car made a buggin in 4,000rpm and we don't know the reason!!!

I make two pulls, one is in 6.5psi (wastegate) and one in 7psi. And in 7psi made less power than the 6.5psi and both pull was use 93oct and have same problem on 4,000rpm.

Here is the dynograph in stock everything, made 158rwhp and you can see the comparassion with the 6.5psi power:
[IMG][/IMG]

Here is the dynograph 6.5psi and made 249whp and 192lb/ft and 7psi made 237whp and 187lb/ft:
[IMG][/IMG]

Any comments about the buggin in 4,000rpm. I try to fix the problem, need help.

Thanks,

Antonio.

 

Check your AFR in the dyno shot here:


notice how the AFR spikes right about 4250 rpm? You might have a problem in your fuel map because all of the sudden you're running very lean.
So it's either your injectors (which it doesn't look like according to the rest of the dyno) or a problem with the fuel map. At least that's how it looks to me and i am by no means an expert.

 

or issit the ports opening up?

 

The problem can be the following:
1- fuel map
2- DW throttle body
3- Secundary injectors, Im using for secundary injectors the stock ones, and the primary is RC 450cc. SFR should sent me the 550cc for the secundary one, but he didnt get the right one, so, at moment I used the stocks one. Somebody know where can I get the correct secundary injectors or better somebody have a upgrade fuel upgrade system with return line??

Your comments will be appriciated.

Thanks,

Antonio.

 

No, the ports was not open

 

Here is another very rare thing, after I make the pull on 7psi and get lower hp, I turn off the boost control, thats mean back to 6.5psi. And I want almost 15 minutes and make again one pull. this pull in 6.5psi only get 183whp with 159lb/ft
in same condition as first two pulls and is running much lean than the two first time. So thats why I feel sometimes the car moves more much faster. I don't know what happened.

Here is the dynograph:
[IMG][/IMG]

Thanks,

Antonio

 

it's not the ports (they don't pop until 6250 or 6750 or whatever) and I don't think it's the injectors. The secondaries turn on at 3750. IMHO, it really does look like it's the fuel map.

 

send me a copy of ur map plus the powerwrite software

 

If you are near SFR, then you may be near SP Engineering (City of Industry). They are the ones that worked on my car, so they know what they are doing with the HKS V Pro.

 

I dont have the map, the tuner has it.

 

twin injector compensation isnt set properly, when the injectors are switching on the air/fuel is going lean

 

How can I set the twin injector properly??? Is something about the secundary injectors?? because I use RC 550cc primary and secundary I use stock injectors

 

So when are you opening the SSV(Secondary Shutter Valve)?
This is roughly the rpm range where the factory ecu opens the SSV,the exact rpm depends on engine load etc.In the case of the factory ecu,the SSV is timed to open with the Secondary fuel injector.
It looks like you don't have enough fuel from Secondary injectors when the SSV opens.

 

3- Secundary injectors, Im using for secundary injectors the stock ones, and the primary is RC 450cc. SFR should sent me the 550cc for the secundary one, but he didnt get the right one, so, at moment I used the stocks one. Somebody know where can I get the correct secundary injectors or better somebody have a upgrade fuel upgrade system with return line??

Your comments will be appriciated.

Thanks,

Antonio.

We have a complete plug and play fuel system available for the RX-8. 1-800-538-9989,Scott

 

Are you positive that the primary's are RC 550's???

 

100% sure, why?? there is any problem with RC injectors??

 

i'm about 95% positive that whoever installed the injectors did not put them in the primary's because RC injectors are too wide to fit in the primary location due to the casting on the center plate. So what i think is happening is, either they left the stock injectors in the primary's or if they were smart they would have swapped them for the larger secondary's which do fit in the plate. This being said you are probably running out of injector at that rpm and the secondary's are engaging too late.

 

Im going to check what you said. But in this case, you basically said is better to replace to all stock injectors and see what happened, right??
What level of HP is good for the stock injectors??? can be use until 350rwhp???

Thanks,

Antonio.

 

I think I remember, although I am not certain, MM stating that the stock injectors were good for about 300 WHP?

 

stock injectors are good up to about 300whp at most, I would suggest replacing the primary injectors with the yellow secondary injectors. then use your 550cc injectors in the secondaries and tune it from there, that should have plenty of fuel for 350whp.

 

Ok, thanks Jon. Is necessary to add a fuel pump??

Antonio.

 

I did the same thing with the 720cc injectors I got from Scott over at Mazsport.

 

our car doesn't even have a fuel pump yet.... so no i dont think you need one, but couldn't hurt for sure ;p

 

I did what you said, put the yellow secundary injectors on the primary position and used the RC 550 injectors in the secundary position. After that the car get worst, the problem of the buggin is still has it and also have detonation when you step the gas. Right now is too lean or too rich?? and made the detonation.