Jacob,
Sounds like a very well thought out build and a very good dyno set up by including both AFR & Boost curves! Lots of good info.
Thanks
Looks like displacment, compression, cam timing, headers, and twin plugs all targeted to help low end and get it into boost quickly.
Yes
All these should add up to a pretty responsive build targeted for low to mid range power.
Yes...its a damn fun street car right now.
From the dyno plots shown I think I see the following:
1) You might be approaching the limit on fuel delivery.
yep...thinking of shimming the fuel head to see how that helps
2) The turbo is reaching its peak efficency at about 4200rpm / 250whp/300chp.
3) Your turbo might be reaching its gross delivery potental (.7 bar @ peak ; .55 bar at 5500rpm).
yes, the turbo boost seems to fall off...can't seem to keep up with 3.5 liters and opened up intake ports
4) You are reaching full boost (.7 bar) just before 3500rpm which seems late given your build and turbo choice.
I need to install my manual boost control to see if that helps. on this particular pull, I had adjusted the wur to in an attempt to delay enrichment. I also think that this may be a factor in the increasing AFRs at the higher rpms, since as the boost falls off, perhaps the WUR enrichment is impacted too. On the street I see full boost at or around 3k depending on gear and load conditions
5) The test was stoped before the motor hit its peak HP potental. It has a great flat TQ curve that was still holding even though boost was falling off and the test was stoped early.
didn't want to get greedy...I told them to stop at 5500 as my expectation was that the K27-7200 would be running out of puff by then anyway and AFRs were climbing
6) This motor should have about 450whp potental at 1. bar with the right turbo, fuel delivery, and tuning. [((350/ 1.55) * 2)= 450].
I think so too...for the moment I'm happy and will be spending my next dollars on suspension and seating...will go for bigger power later or when the K27 takes a dump on me
A GT 35 Turbo might be a good fit here. It might better hold boost through the upper rpm and do so in a more efficent way that helps keep the charge cooler.
yes...recommended by Chris Carroll. Though, I will admit to having a hard on for pkracer's Comp Turbo CT61?...triple ceramic ball bearing sounds like a freaking lear jet.
I could be wrong so all I am saying is just watch your boost curve. If you can not hold boost through 6000rpm it is small and could be overly heating the air.
With its ball bearing construction and more efficent turbine it might even boost sooner and help your low end response.
I am not an expert, I just love this stuff so take this for what it is worth.
