New DP, low boost

[Be4u]

I love this thread!

[Scoobum]

Steve...chime in on this. What if he were to barely pull the rod over the arm...and then adjust Erics low/high gear timing to Erics street chip timing...and turn the alky off...with say...10 percent high gear fuel added. It would take alky out of the equation. We'd need to know what Erics street chip timing is. I'm sure one of the guys has one. Just a thot.

[Steve Wood]

We started off not being able to build much boost....not sure what it would prove....that we could run 18 psi or so with no timing retard at 16 degs of timing if we took timing out? 

As I said, I am not sure that being too rich is the problem, but, I have seen cars (like one of mine out in the shop) that won't make boost when the O2s get much over 800 mv so I may be on a tangent  

My first thought was the wastegate rod...he had very little tension on it and we normally need about an 1/8" tension for the gate to seal and not get lifted off the seat while spooling....in my experience.  That seems to not have been the problem.  Wiring it closed did not make boost.  He has some small leaks and that does not help, but, does not seem to  be the problem.

Last time I saw this on some one else's car, he had some exhaust leaks including at the turbo mounting joint to the exhaust up pipe.

[Scoobum]

Without being there...this is a tough one...at least for me. I'm wondering if he's having trouble even boosting it on the footbrake. I've had people tell me one thing...and when I get there...it's something different. I'd be interested to know how fast/slow it boosts with the alky turned on and off. It'd be a start. Time/boost can be recorded on PL.

[Steve Wood]

he's boosting from a 50-60 roll which should spool pretty quickly...

[Scoobum]

he's boosting from a 50-60 roll which should spool pretty quickly...

Should hit his desired boost pressure pretty damn quick from that speed.

[Steve Wood]

Yep.... that's where the car has the most load on it.  So he will have the most combustion heat and need the most alky

[Shimy87]

update, took car to work this morning with the powerlogger. wastegate arm set at 3/16 pull just to be sure it was tight, alky gain knob set to 5, wot pull in 3rd from 55 to 85 mph, quickly builds boost to 18.8 lbs and O2's were high 830's low 840's. Continued to do this test, lowering the gain knob 1 number a time. same results with O2's each time, got all the way to 1 on the knob and same thing, 18ish boost and high 830 low 840 O2's.

Next step is to lower initial gradually. My concern here is I hope to get a transition where the O2's come down to 800 but if this is the boost issue, boost should start to come up to my desired level of 24lbs, I don't want this pendulum to swing over to quickly.....O2's drop and boost shoots up and I'm in the head gasket game again.

Question here, you guys think I should bump up the turn on point a touch? I think Scoob will say yes, not sure what Steve will think?

[Be4u]

Thought I would throw this out there but maybe I should just be quiet because I can't tune a radio. Did you try disabling your alky, turning everything down and see where your o2s are? Just to make sure everything's ok pre-alky.

[motorhead]

When in open loop I always tune for the most boost/timing with the supplementary injection system turned off, and then start adding it in along with more timing and boost.

If tuning in closed loop you can set your target AFR (or AFR curve - ie. richer at MBT, leaner at the top end), then massage the boost and timing curves to suit, while cranking up the alky or whatever.

In my Buick it was propane on around 18psi and alky in at 25psi, and ran it out to 30psi.

[Steve Wood]

The problem with that scenario (from my perspective) is that in third at 18 psi, it should be spooled and making heat so it should continue to increase in boost at that point.

On the other hand, if the mixture is dominated by alky, it may not. That is the reason that I think the beginning alky should be reduced by adjusting the initial flow amount down to get some heat back into the process.  The gain knob will allow it to ramp up faster if needed toward the end of the process.  I think Julio's instructions state that if the gain control is turned on and set to the minimum, you should be seeing some timing retard.  If not, he suggests reducing the initial a little bit at a time until the gain control starts having the desired affect.

At this point, to avoid some confusion, maybe it would be worth a call to him and seek advice from the guy that really knows the system?

[Shimy87]

Tuning to AFR with a tt chip.......don t know how

[Shimy87]

Called Julio this morning and waiting for a call back

[Scoobum]

I started from scratch and reread this thread...it's getting long. You wired the puck closed...and only got 15 PSI. My gut tells me either you have pre turbo leaks...the puck isn't sealing...or you made the hole in the exhaust housing too big. Everything I ever read says go no larger than .900...you went 1 inch. There's some physics involved here that I don't honestly understand in relation to going too big with the wastegate hole. Whether this is your problem or not, I don't know. I'm asking Steve to step in...cuz it'd be a good lesson for all of us to understand it. In my mind, you've pulled enuf WOT fuel that it should hit mid 20's boost easily. I'm out of ideas.

[Scoobum]

Steve, Dan and I have installed a few of Julios systems with different sized turbos. With both Eric and Julios systems on default...and the boost set to a minimum of 20 psi...we haven't had an issue. The only problem we ran into was if the boost was set below 20...the car would bog in high gear from too much alky. Bump it to 20...shazzam! Like I said, I'm out of ideas. Contacting Julio is a good idea.