When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Went to the dyno today to find a bit more power for time attack/hooning. For SLB map we had to gap plugs down to .028. We ran the 179282 WG "low" boost actuator. The lumpy power past 6k was the WG being blown open despite being like 90% D/C. So we swapped in the 179283 "medium" boost can and went back to the dyno. Despite turning boost duty way down from the SLB map, we still blew out the spark. It made something like 15psi at 4000 I think. So we gapped down to .022 and kept dropping boost duty until it would run consistently. We were able to get to about 17psi up top but only about 10-12psi below 5000 I think. Trying to keep the trans alive so we kept wtq under 300.
These were new but generic brand Toyota COPs. Plenty of data points for folks running bigger gap and more boost with OEM Denso COPs. Lesson here is buy used Denso/OEM COP's, not aftermarket brands no matter how cheap they are. We also hit 100% injector D/C despite running an NB (60psi) FPR atmo referenced. Should have another 50-80whp of headroom so we're not sure what's up there. Have to stick an FP gauge on it and see.
So the fun was seeing what the Trackspeed Engineering EFR6258 was capable of at full boost. If one extrapolates the blue plot line, you end up with about 370whp and maybe 310tq. Mind you this is running 11.0:1 AFR (lambda) up top which is way fat for E85 and 20.5°. We ran 24° in Deviate so there is more headroom in both fuel and spark.
We also hit 100% injector D/C despite running an NB (60psi) FPR atmo referenced. Should have another 50-80whp of headroom so we're not sure what's up there. Have to stick an FP gauge on it and see.
The atmo reference is killing you. Every 1psi of boost you add is like turning the base pressure down by 1psi. I've seen similar limitations, maxing out 1000s on just 300whp and 16psi because the car was on an NA FPR. Add an FPR with a boost reference and you'll find another 100whp worth of fuel.
The atmo reference is killing you. Every 1psi of boost you add is like turning the base pressure down by 1psi. I've seen similar limitations, maxing out 1000s on just 300whp and 16psi because the car was on an NA FPR. Add an FPR with a boost reference and you'll find another 100whp worth of fuel.
I agree with Andrew, Gotta be referenced at those boost levels.
I hope it's only the brand of the COPS that's the source of snuffing out the spark. In you shoes I would look at where the coils get the juice from. I believe it's the ECU. What does the power feed to that look like?
I fought the same thing on a twin turbo build I did. Not a great comparison as that was a dizzy/single coil setup. Needed CDI to solve that one. With COP and 8k RPM you've got more than enough recharge time. Overly fat mixtures do make it harder on the ignition so try and clean that up if need be.
Look forward to the final results once things get fully sorted. Looking REALLY promising!!!
The atmo reference is killing you. Every 1psi of boost you add is like turning the base pressure down by 1psi. I've seen similar limitations, maxing out 1000s on just 300whp and 16psi because the car was on an NA FPR. Add an FPR with a boost reference and you'll find another 100whp worth of fuel.
Even just at 9psi of boost you are getting less fuel pressure with an NB regulator than an NA regulator. Toss on an AFPR and run 60psi base+boost reference. I ran up to like 90psi of fuel pressure on the dyno. Made 380hp at 67% duty cycle.
Originally Posted by k24madness
.I believe it's the ECU. What does the power feed to that look like?
ECU sends the coils a trigger signal. The coil power comes from the harness. through the main relay I believe.
Even just at 9psi of boost you are getting less fuel pressure with an NB regulator than an NA regulator. Toss on an AFPR and run 60psi base+atmo reference. I ran up to like 90psi of fuel pressure on the dyno. Made 380hp at 67% duty cycle.
Insert "That's not how any of this works" meme. Please read what you wrote. Out loud. Slowly.
60 PSI of fuel pressure at 0 PSI boost is still 60 PSI of fuel pressure at 9 PSI boost. The term you're looking for is differential fuel pressure. Two different things.
If you put an AFPR and run 60 PSI base pressure and run the reference port to atmosphere, it will still be 60 PSI all the time. Which was what he was already doing. Not sure why you would suggest that? It needs to be plumbed to intake manifold pressure so it is vacuum/boost referenced, and so that the differential fuel pressure remains constant.
I think youre aggressively telling him exactly what he already said.
Nope.
Originally Posted by Savington
Ya, semantics. We are smart enough to figure out when one is referring to DFP/base and when one is referring to rail pressure.
True, but this is how people get confused. The part I was more concerned/confused about was the suggestion to switch to an adjustable FPR, but still have it atmosphere referenced and set to 60 PSI, which achieves nothing.
So this was surprising. At Buttonwillow today testing out some different spring rates (1400/600!). After the dyno yesterday we took a used set of genuine Toyota coils off of Sonny's car and put them on Bullet. The same map that ran fine on the dyno blew the spark out around 5800 here. Put the set of coils from the dyno session back in and it would pull harder to about 6600 but still blew the spark out. Dang it. Dropped about 10% of boost duty out at 6000-7000 where it was misfiring and it's all good now. What I find surprising is that the new aftermarket coils supported a bit more pressure than used OEM. It's around 11.6:1 when it misfires. I could go just a touch leaner but that's not the problem.
This is all sort of academic as this is probably the last time we'll run Bullet in the high boost configuration. Vegas is finally back from TC so it is starting to go together now.
Moral of the story is if you're headed north of 350whp or 20 psi then LS coils aren't a bad idea..
Thanks to George (Miataman00) , Cowlover556 and a few other guys for helping me load Bullet last night. About 2" of clearance from splitter end plates to ramp cables so it was threading the needle. 2hrs to pull nose so that option was overlooked.
lol at the braking comment. I finally got the tires to lock but it took a hefty shove on the pedal and yanked me in the harness like an F1 car. Anxious to see my peak braking G once I d/l the data. Saw a 1:44.69 on the MXL2. and a few other high 1:44's. Missed shifts on every fast lap attempt though. Finally pushed 4th off the shaft I think, circlip failed. Shift forks also toast. Limped in having to hold the lever in 4th.
11-30-2017, 09:42 PM
0
