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Looking at this compressor map, I'm spinning about 48,500 RPM at shift.
I'm guessing that's right around 80lb/min flow.
Ignoring everything else about the combo, what is the smallest injector you guys would run?
I'm running 42's right now and I'm thinking they might run out of fuel.
Now in contrast, I used to run an S-Trim. Spinning it at 49,000 RPM and it only made 550hp (crank), where according to the compressor map it should have been putting down around 70/lb min. That combo ran 36lb injectors.
I dont see how 36’s worked either lol. Do you know what the duty cycle was? What fuel pressure?
42 usually is maxed near 600-650 hp roughly
Duty cycle was near static, so lets say static. Fuel pressure was 50psi.
3640lb car trapped 120mph at 90 feet elevation. I'm coming up with around 550 crank HP to do that. Yet, the blower RPM should translate to more HP according to the compressor map. I think the maps are generous.
That might make more sense then. If rated36 at 43.5 psi fuel pressure then they would flow closer to 39 lb and really efficient setup might squeeze that at 100% duty
I would lean towards a 60 siemens deka to give plenty of room on duty cycle and more blower speed
Or a 42 rated at 43.5 you can crank up to 58 psi base. Get you closer to a 48-49 and run it hard if pump keeps up
I would say at a minimum 60's. My car did 430whp last week with lots room for improvement according to the tuner and it was at 46% DC. (V3 Si on 6 lbs)
I would say at a minimum 60's. My car did 430whp last week with lots room for improvement according to the tuner and it was at 46% DC. (V3 Si on 6 lbs)
Which 60s are you running? I may bug you for a copy of your tune to see your injector settings. The Siemens have a 1.14 msec turn on, and .84 msec turn off. (that's really terrible lol). I'm running alternating batch firing strategy right now on the Ford 42's and the car runs amazing. I don't wanna lose idle or part throttle drivability.
I added a PATC modulator boost kit to the TH350 and it actually shifts beautifully now!
Luckily the car hasn't got enough traction to make enough boost to melt down yet. At 30mph even moderate throttle transition lights the tires on fire. I even bought brand new soft tires. It's simply not possible to give it too much throttle on the street, *** end kicks out.
I'm thinking on a prepped track, or dyno, it will make a ton of boost though.
Ran bosch 36’s on 730 as well in my 305. Both 8d and 59$
Got me. I don't know what happens exactly when you command a pulsewidth shorter than the open time. One would assume you get no fuel, but I don't own an asnu to see.
So I guess I'll try some 60s.
Do you think looking at that compressor map, based on the impeller speed that it's making around 800+hp ?
Part of me wants to say the Vortech maps are generous based on my own experience with an S-Trim, but then again, that car had crappy sportsman II heads, so maybe it would have made more power. My 412 has good heads.
Here's a log of my old Lucas 42s @ 60 psi hanging in there up to 140 mph (data exported from TunerPro). Log includes WBO2, extended air flow and load signals along with MAF air temperature (post intercooler) in addition to standard data stream items:
links work better with chrome or firefox. IE may have trouble with it. Datazap allows you to zoom in/zoom out and turn signals on or off for display as desired. Feel free to play around.
P600b 383 with 4" core intercooler, 4L80E and 3.73 gear. 1986 Y-body, MAF car w-165 ecm.
I think this was about 12 psi at the manifold...15-16 or so at the blower. With this configuration, 42s have provided enough fuel for about 6,800 rpm. Don't think this log peaked that high. P600b should flow up to 1150 cfm and be somewhat similar to a T-trim.
14psi on the S-trim/355 combo, around 180 degrees.
It weighed 3640 lbs and trapped 120mph ever pass. What's your flywheel HP estimate on that? I came up with about 550. Stick car.
-- Joe
Yeah 500-550 seems reasonable. 2.0 pressure ratio doesnt line up with 49,000 rpm blower speed but pressure at blower may be higher? Not sure.
180 deg is hot so theres power lost there for a given mass flow. Map shows corrected weight flow? Or do they want you to adjust via the equation?
Either way, the old heads being not near as good as afr 210’s, you’ll probably see less boost at same impeller speed cuz the motor will be ingesting more air. That motor on 14 psi will be over 600 whp thru a manual trans. The 383 d1sc i tuned had 195 afr’s and a 224/230 xfi cam with big tube tpi and was 550 whp or so around 8 psi at 4500-4600 lol. He had 60 lbs but i dont know the duty cycle. Ebl flash tuned
Yeah 500-550 seems reasonable. 2.0 pressure ratio doesnt line up with 49,000 rpm blower speed but pressure at blower may be higher? Not sure.
180 deg is hot so theres power lost there for a given mass flow. Map shows corrected weight flow? Or do they want you to adjust via the equation?
Either way, the old heads being not near as good as afr 210’s, you’ll probably see less boost at same impeller speed cuz the motor will be ingesting more air. That motor on 14 psi will be over 600 whp thru a manual trans. The 383 d1sc i tuned had 195 afr’s and a 224/230 xfi cam with big tube tpi and was 550 whp or so around 8 psi at 4500-4600 lol. He had 60 lbs but i dont know the duty cycle. Ebl flash tuned
The pressure ratio thing never made any sense to me. The airflow from impeller speed seems straightforward, but how the heck can they predict what the pressure ratio will be? I'd assume the same airflow on a 5 liter motor wouldn't produce the same boost as a 8 liter.
I have no idea on the map if it's corrected. They are not very helpful with these questions.
The old setup was a 355, this is a 412.
I was shooting for 600 fwhp. This combo might be a little more powerful than I wanted. Ugh.
Will idle like **** though. I used to run a cc306 for 1 summer on one of my vettes and it was terrible.
I like the idea of the smaller pulley at low RPM. Maybe I could buy an electronic wastegate and tie it into my MS to provide some boost control.
-- Joe
Cc306 is a bad example lol old lazy lobe. Sounds bad **** tho and does make ok power. Get a faster lobe and it wont be to bad. My turbo car wasnt bad 246/252 .640” you wouldnt need to go quite that big i dont think
Cc306 is a bad example lol old lazy lobe. Sounds bad **** tho and does make ok power. Get a faster lobe and it wont be to bad. My turbo car wasnt bad 246/252 .640” you wouldnt need to go quite that big i dont think
I dunno. I guess if I ever lost interest in the blower and decided to mill the heads, but for now everything works.
Which 60s are you running? I may bug you for a copy of your tune to see your injector settings. The Siemens have a 1.14 msec turn on, and .84 msec turn off. (that's really terrible lol). I'm running alternating batch firing strategy right now on the Ford 42's and the car runs amazing. I don't wanna lose idle or part throttle drivability.
-- Joe
Sorry for the delay, just got back from vacation. Siemens Deka, i dont remember what version though. I was never able to find a accurate voltage compensation number for the 60's. I think the 80's was around .130 and thats i think where mine sits at the moment (and it runs fine with all the electrical loads on now) if you want a msq let me know.
06-12-2018, 12:37 PM
Siemens Deka, i dont remember what version though. I was never able to find a accurate voltage compensation number for the 60's. I think the 80's was around .130 and thats i think where mine sits at the moment (and it runs fine with all the electrical loads on now) if you want a msq let me know. 