mark57

Brief background: '93 FD, RP 2mm stockport, Turbonetics T66P, PFC w/ Datalogit, and all other modifications. Done in early 2003.

Last week, discovered small tear in my HKS standard wastegate diaphragm. And, an LX91 coil was making erratic spark [my lead ignition is: PFC > ignitor > two Jacobs FC1000 boxes > two Crane LX91s > Taylor wires > NGK 9's and trailing stays stock].

I was not happy with GReddy PRofec B W/G set up: Compressor to "In", W/G sideport to "Out", W/G top port open to atmosphere, controller dip switches set on-off-off-on. I'm told this is the fail-safe way of overboost protection in the event of boost controller failure.

Symptoms: Car suffered power loss at WOT w/ PRofec turned on. Boost gauge read 12 and 15 psi on low and high settings. Car performed better with PRofec off and running on 10# W/G spring. Had gone to chassis dyno three weeks earlier with dismal result and left w/o finding the solution to problem [made a weak 300 WHP].

I was prepared to 'give it up' for a Spec 2 and plumb it according to GReddy instructions. I bought a $55 14.2 psi [1 bar] W/G spring as I would eliminate the electronic boost controller altogether if I got good performance with just the heavier spring.

Test drive: Boost leaped to 21 psi. That's no good. Disassembled W/G, found torn diaphragm, robbed knock-off diphragm from a knock-off HKS W/G at shop. Tested again, everything worked beautifully: PRofec was indeed working and working well with 10# spring reintalled. It was easy to adjust, yet car power was still a little bit off, it was not as sharp as it could be.

We consulted by phone w/ a well-known expert/professional who is incredibly patient and kind; he told us to check the ignition and reassured us the W/G is plumbed that way for enhanced engine safety. Sure enough, using a spark plug tester, a LX91 was erratic. We replaced both coils. Neither coil is that old and the amps are a year old.

My questions are: How exactly does the boost controller solenoid motor and dip switches work, what is the ideal hi-po 13BREW ignition, and what is the best wastegate for under 500 WHP, and where does one obtain the best price on HKS wastegate rebuild parts?
Car now runs better than it ever has. Pulls strong and cleans and fast! Must've had a torn diaphragm from the very start of the single turbo conversion.

P.S. I replaced the fellow's knock-off diaphragm w/ a genuine $105 HKS unit. This car is killing me sometimes.

r1dreamer

iTrader: (4)

hey so you have a 40mm hks wastegate and it holds what type of boost levels for you. cause i just tuned wiht steve kan and i have a t04s (1.00 a/r divided, .7 compressor ,62-1) with full 3in exhaust and all the other mods with a stock ported motor, and the wastegate would hold 10psi until about 6500 rpm then it would creep to 19-20 real fast.

i had this wastegate on my old set up with a t04e (1.00 a/r divided,.6(3in inlet), 60-1) with 3in downpipe to a 2-1/2in midpipe and no intake filter on stock ports and it would hold 10psi perfectly.

your sayin that your standard wastegate holds the boost from a t66. but mine cant hold a t04s, hmmm. i was thinking of buyin a 50mm racegate.

thanks
brandon

mark57

Boost controller "Off" = 11.2 psi w/ HKS 10# w/g spring. Yeah, I know, it's now making more boost than the spring is rated. It was making only 10 psi until these issues were repaired.

Boost controller "Low" = 12.5 psi.

Boost controller "High" = 16.2 psi. Defi boost gauge has 1.25 psi increments, ie. three hash marks between every "5" value indication marks.

I don't think the W/G is overwhelmed; the boost is well-controlled w/o spikes. My turbo is T66 P-trim w/ 0.81 hot-side, undivided. I changed from the 0.96 to the smaller hot-side to get better low-end spool up; it sees boost 500 RPM sooner and is more useable on the street.

I street-tuned w/ Steve last year. Unknown at the time, my car had undetectable issues. With those issues resolved, I'm running exceptionally well and that certainly speaks volumes for Steve's vast knowledge and abilities. New Orleans now has a new dyno facility w/ a very knowledgeable staff, so I'm anxious to get Steve back down here to tune on that and make refinements for hot-weather optimization as the weather gets incredibly humid for months at a time.

GoodfellaFD3S

iTrader: (213)

Car is lookin' sweet Mark! Glad you are getting your bugs worked out, I am doing the same thing here in NJ and happier than a pig in ****

mark57

Thanks Rich. NOthing quite like a turbo rotary that has sharp, responsive power. With the boost and ignition problems solved, the only issue now is excessive flamage. I've been stopped for it once w/o a ticket or warning [deputy was concerned my car was gonna burn down], but I know it's gonna happen again.

I take it your job is going well.

APEXL8T

OK so now can I have my diaphram and coils back? Its about time now lets get back to the dyno!

mark57

Wheeew - I'm glad yer not asking for the PFC back....yet.....

I expect your diaphragm from XS-Engineering to arrive Monday and Freddie can reinstall it int your wastegate; your coils are on the shelf - couldn't use them. Ready for the dyno yestereday.

GoodfellaFD3S

iTrader: (213)

flames kick ***. the job is rockin', thanks for asking. I saw some pics of teddy a's fd, she is looking sweet with the new 17 inch spinnas