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Hi Brian! Congrats on the awesome numbers and build!
I am curious if you have come to a conclusion on the exhaust diameter for the higher HP sc applications.
i am running the c38-92 like you in the new kraftwerks kit with 90mm pulley on an ap1 and am making 490whp/304wtq with 70mm test pipe and 70mm single on ~e65/70 @ 20psi.
i have the exact same fuel as you (1300x, Walbro 450, sos hardline, aem fpr and rail, 60 psi base pressure) and am at 89% duty cycle at 8500 rpm.
I have a 3inch TP and hks 75mm single sitting in the garage waiting to be installed and retuned, however, I am trying to gather info from people who have done this.
Are you you at a point where you think the engine will benefit from a larger diameter exhaust?
i remember in the old exhaust piping thread that 63>75> 70 in terms of power output. Would you still say this is the case?
I'm not certain at my level of HP if a larger exhaust will help anymore or not. ...possibly. I am still on the Fujitsubo Legalis R which is a 60mm to dual 50mm. Obviously at some point it may become a restriction I'd believe. When we were looking at the reason for the hp cap around 450whp SAE we tried removing the exhaust from the header and saw no difference with it disconnected, so I don't believe changing it out to a larger diameter will make much if any difference...at least at this power level. At this time I do not plan to change it out to see.
I'm assuming you have an F20? Based on your results it sounds like you have a pretty decent intercooler core if you are seeing an actual 20psi with that setup. Seems unusually high and currently the highest I've heard of with the KW kit. Seems almost too good to be true!
On the C38-92 vs the C38-91 the ONLY difference is the intake mouth diameter of 76mm (91) vs 89mm (92). The output diameters are both 63mm. I'm guessing you read this from a while ago? https://www.s2ki.com/forums/s2000-fo...header-817368/
My WHP figures are as follows:
SAE 537whp
Uncorrected 544whp
STD 551whp
After reading your other post I'm curious as to why being on E85 you are only at 9 degrees of timing. On 93 octane pump gas I saw 461whp (STD) at 13 degrees and backed it down to 10 degrees for approximately 435WHP (SAE can't currently remember the STD figure). The 551whp on E85 is at 18 degrees of timing.
...ok...sorry...I misread your post in the other thread...I thought you were at 9 degrees of timing on E85...it actually says 9 degrees on 93. What is your timing on E85? As it has been a while since I memorized all the specs...what engine RPM is the 90mm pulley good to on an F20? That might be why you are getting the boost level you are... meaning you might be over spinning the blower. I think you should be on a 100mm to keep within spec. I'm on a 95mm at 8500 engine RPM on an F22 netting a blower speed of 90,592 netting around 17-18psi. I'd probably be at 20psi with a 90mm at 8500.
I don't know if I'll be tinkering with the S this year. I just picked up a 2018 Championship White Civic Type R. I'm still aquiring parts for that right now!
...ok...sorry...I misread your post in the other thread...I thought you were at 9 degrees of timing on E85...it actually says 9 degrees on 93. What is your timing on E85? As it has been a while since I memorized all the specs...what engine RPM is the 90mm pulley good to on an F20? That might be why you are getting the boost level you are... meaning you might be over spinning the blower. I think you should be on a 100mm to keep within spec. I'm on a 95mm at 8500 engine RPM on an F22 netting a blower speed of 90,592 netting around 17-18psi. I'd probably be at 20psi with a 90mm at 8500.
I don't know if I'll be tinkering with the S this year. I just picked up a 2018 Championship White Civic Type R. I'm still aquiring parts for that right now!
thanks for writing back!
i think I’m going to put on the 3in header back as well as 1700x injectors and tune it and see what I get.
with regard to pulley rpm - 8450 is my supposed blower max rpm. I spoke with kraftwerks and they even said I can rev it out to 9200 safely (I.e. over spinning the -92).
i was very surprised by the boost level as well. I read a post by CJ @ kraftwerks a while back that said the more restricted the system is, the higher the boost is likely to read. The problem with that theory however is that I have a completely free flowing system (blox 4inch velocity stack 3.5 inch intake piping, skunk 2 alpha header, 70mm TP and 70mm single exhaust).
i am very curious about your IC piping test. I am close to upgrading the sizing like you did as it seemed to work well for you. The IC core is the regular kraftwerks core.
i guess every car is a different animal, haha. Either way, silver is the fastest color, right !!
edit: I will have to check my timing numbers - the tuner did not tell me when I picked the car up. What are you running for timing?
edit 2: that civic sounds like a blast! Pics or it didn’t happen
i think I’m going to put on the 3in header back as well as 1700x injectors and tune it and see what I get.
with regard to pulley rpm - 8450 is my supposed blower max rpm. I spoke with kraftwerks and they even said I can rev it out to 9200 safely (I.e. over spinning the -92).
i was very surprised by the boost level as well. I read a post by CJ @ kraftwerks a while back that said the more restricted the system is, the higher the boost is likely to read. The problem with that theory however is that I have a completely free flowing system (blox 4inch velocity stack 3.5 inch intake piping, skunk 2 alpha header, 70mm TP and 70mm single exhaust).
i am very curious about your IC piping test. I am close to upgrading the sizing like you did as it seemed to work well for you. The IC core is the regular kraftwerks core.
i guess every car is a different animal, haha. Either way, silver is the fastest color, right !!
edit: I will have to check my timing numbers - the tuner did not tell me when I picked the car up. What are you running for timing?
edit 2: that civic sounds like a blast! Pics or it didn’t happen
Good luck with everything. I'd be careful reving over that 8450 with the 90mm pulley...these blowers don't take well to that.
Mind you it wasn't just the piping increase that was successful for me. I also changed the pipe routing that removed quite a few extra bends etc smoothing out the flow path. You must have a very well flowing IC core. My timing is at 18 deg on E85.
Hi,
I have a question about your dual OCT configuration. If I do understand, each valve cover output (the PCV one and the over) is only routed to a vented OCT.
You have nothing routed to the air intake in order to create an air depression and ventilation ?
I bought an OCT with 2 inlet and 1 outlet: I was planning to route the 2 valve cover outputs to the OCT, and then route the OCT to the blower intake to "force" ventilation". Bad idea ?
Hi,
I have a question about your dual OCT configuration. If I do understand, each valve cover output (the PCV one and the over) is only routed to a vented OCT.
You have nothing routed to the air intake in order to create an air depression and ventilation ?
I bought an OCT with 2 inlet and 1 outlet: I was planning to route the 2 valve cover outputs to the OCT, and then route the OCT to the blower intake to "force" ventilation". Bad idea ?
Hello,
Either way will work. With boost there is plenty of positive pressure inside the engine and I don't believe that any vacuum to remove it is actually "necessary" (but definitely need to escape via catch can etc). venting to the intake tube will actually change your tune slightly due to the gasses now being ingested...again a minimal thing.
05-18-2018, 07:29 PM
Made (cut out and laser etched) by my friend Paul (Mountain Man). Bent and polished by me.
