Turbohead

Anthony,
Sorry I had to run out on you last week...My mother inlaw made me do it!

My 3.6 has about the same mods as yours except no cat. you could drive it and tell me what your seat of the pants says.

One question I have for stephen is do you modify the WUR in conjuctiuon with the head Mod.??

Btw I 'm at Watkins Glen right now and the hotel as a WI FI set here cool huh?
Boy are we sick or what!!!!
Elliot

TrackDays247.com

So is it safe to say that with the IA fuel head mod that the CO can be trimmed to a low(er) level?
What should the idle CO be?

PorschePhD

Yes, but the number you seek will be determined by your AFRs at WOT. Generally well below 2%.

sand_man

Bringing this one back from the dead.

It looks like I might be going to the tunable fuel pressure system that Simon (m42racer) describes earlier in this thread. Some have refered to it as a "digital WUR". I have the Imagine Auto fuel head and I just can't get my upper RPMs to lean out. My car is like a missle up to about 4,500 RPMs and then my AFRs are in the 9:1 and 10:1 range. This richness slows the engine acceleration down dramatically.

If I go any leaner (counter- clockwise) with my fuel head adjutsment screw, the engine won't start.

Before I sink another $1,000 into this **** for the system, does anyone have any thoughts on doing that el cheapo "adjustable" WUR mod that requires drilling and tapping? How hard is this mod to adjust? Anything else I should check? Anything else I can adjust?

PorschePhD

It is fairly simple and most of us can walk you through it. I can take pics of the one on my wifes car if you would like. I also think there is a write up somewhere.

sand_man

As usual, Stephen, THANK YOU! I have seen a few write-ups on Pelican. My only concern is being able to adjust this thing. How hard is it to access and adjust the WUR? Electronic gizmos are great, but if I can achieve my goals for a few bucks, I'd be happy.

SGOGT4

I ended adding an adjustable WUR to my IA fuel head as I was just not getting enough fuel up top. As long as you have some sort of an aftermarket intake on the car, adjusting the WUR is pretty easy. If you have a stock airbox on there it is a PITA as you need to remove the intercooler and airbox in order to get access to the WUR. The midrange and highend adjustments are actually located on the underside of the unit so the whole thing needs to be taken off to adjust. Once I got the hang of it I was able to pull the thing off, make the adjustments, and have it reinstalled in 20 minutes or so (assuming the engine isn't hot!).

I had the work done on the WUR completed by a great guy who frequents rennlist. His email is below.

bleask@***.net

Olli

I can second this recommendation. I had the WUR in my car and a spare WUR
made adjustable for me by Brian Leask. Couldn't hope for a better business experience in any respect.

JBL930

Sandman, have you considered going for a bigger turbo to make use of all that fuel? What boost are you running?

sand_man

I'm running a K27-7200 with .80 BAR of boost. My turbocharger still has a lot of life left in it. I'd hate to replace it so soon. I guess that's another option.

sand_man

One thing I need to do, is have a look at my at WUR and verify all my connections. Is there a vaccum conection at the WUR...possibly a leak? My car is an '87 model. Also, all of my connections to the Imagine Auto fuel head would be identical as my original fuel head, correct? The reason I ask is that the fuel head I got from Imagine had one of the connections blocked off with a small bolt.

JBL930

If you went to 1bar, or even 0.9bar you would lean out some and gain more performance, cheep simple win win situation

TrackDays247.com

What did the adjustable WUR modification cost?

NSXTC

I also had the WUR mod done by Brian Leask. That got my AFR dialed in for boost enrichment and everywhere in between. This is a worth while mod and he'll dial it in for your mods.

But what Brian's doing now is even better where we were able to delay the boost enrichment until a specific RPM.

Before this mod, I was getting really rich as soon as boost hits around .5 bar (as low as 9-10 AFR to allow for the leaning when at high RPM). This bogged the engine down a bit. Now, we don't allow boost enrichment until 4600 RPM and my AFR curve is FLAT. It's steady between 11.9-12.2 AFR all from 3000 RPM to 6000 RPM!!

When the boost enrichment does kick in, AFR drops down to 11.1 for less than a sec but steadies out again around 12.1-12.2.

I have the log from my LM1 + LMA-3 which shows AFR, boost, and RPM. I'll try to see if I can do an image capture. It's incredible how I can get such a 'flat' AFR curve from CIS. This will definitely increased my torque which translate to even more HP. I'm guessing a 10 RWHP gain with the flat torque curve. I'm going to dyno again, but this should put me at around 413 RWHP! => ~485 HP 8)

JoeMag

NSXTC -- would be interested to what you're dyno says...

Others -- I put the delay into my wur (rpm switch and solenoid), it helps in the lower rpm range, matter of fact don't have wur kick in until ~5k rpm+, and have the adj wur. works real nice. hp / torque gains are below. I can tell you from experience that adjusting idle CO has very little (actually not noticable via LM1) from ~3% CO on up in higher rpm range.

rpm.....hp....tq
3000....3.....4
3500....11...16
3.8-4.3k..25 to 32....27 to 39
4500.....11 ....12