89 Voyager 1/4 mile times are in!

[moparzrule]

Yeah that'll definitely hurt your power quite a bit. If you aren't using that nipple I'd suggest actually removing it and just putting a 1/8'' NPT pipe plug in there instead.

[Vigo]

Boost leaks move the compressor to the right on the turbo map, which means it puts out hotter air at the same pressure until it just cant keep up with the desired boost level, at which point you are overspinning the turbo like crazy.

I doubt that is the WHOLE problem but any time you can correct ANY problem, it's a good thing.

[Ondonti]

Boost leaks move the compressor to the right on the turbo map, which means it puts out hotter air at the same pressure until it just cant keep up, at which point you are overspinning the turbo like crazy.

I doubt that is the WHOLE problem but any time you can correct ANY problem, it's a good thing.

vacuum cap seems like a big problem but he was making his desired boost. Possibly his intake temps went up enough to pull timing. Flow wise, turbos walk all over little boost leaks like that. The extra heat is the part you might not get away with.

I think you mentioned it before but lowering boost is always safer and smarter than lowering timing. Very true if you have a boost leak hiding somewhere. I don't know if there is a cap to timing pulled. Obviously a lot of guys blow their motors no matter how good the knock detection is. I bet they do this while ignoring or overriding the system. Seems like you can add so much timing or boost that the knock pull doesn't help.

[jefo]

Well I added a catch can along with fixing the boost leaks and the same thing.

However, I found that the motor mounts have way too much play in them, and the brake booster nipple on the back of the intake manifold has clearly been hitting the heat shield on the firewall. The downpipe also has a dent in it from it hitting the steering rack.

I'll have to replace all the mounts before I continue, but it seems plausible that the any of the metal on metal contact could be causing false knock.

[A.J.]

Well I added a catch can along with fixing the boost leaks and the same thing.

However, I found that the motor mounts have way too much play in them, and the brake booster nipple on the back of the intake manifold has clearly been hitting the heat shield on the firewall. The downpipe also has a dent in it from it hitting the steering rack.

I'll have to replace all the mounts before I continue, but it seems plausible that the any of the metal on metal contact could be causing false knock.

I'm using all polymounts and I still had to much engine movement so I added Johnny's bobble strut mount and K-member bracket to the back of my auto trans and that helped a lot. I'm fortunate though, the 31TH transmission has bosses built into for a rear mount it so I just modified the stock rear mount to accept Johnny's bobble strut. You'll probably have to build a bracket and attach it to rear diff cover bolts.

[moparzrule]

A poly front mount and bobble strut are pretty much mandatory for any high power because the engine rocks so badly. But you also need trans and side mounts in good shape and not sagging or else that'll give you axle trouble.

[GLHNSLHT2]

Was reading road and track a couple days ago and they stated that not only does Sonoma have a head wind it is also UPHILL!!! So that could be your big issue right there.

[jefo]

Went back to the track with a new knock sensor, some aero mods (sideskirts and airdam), street tires with the rear seat in and all ran a 14.3 at 99.8mph with 2.35 60ft. 23psi boost and 15deg base timing. Knock sensor light is still going on pretty much the whole track lol so who knows. I'll have to talk to the tuner. All mounts are now poly including bobble strut, except for passenger side.

I would have run the mickey thompsons, but the clutch can't handle a launch with those. I have a 6 puck waiting to go in though.

[Vigo]

Deep 13s with slicks and a good clutch. Interested to see what you find out about the knock readings.

[wheming]

I'd find out why and how bad your knock retard is before proceeding. New clutch isn't going to help if you damage a piston.

[Ondonti]

So you ran those numbers but it was pulling timing all the way down the track?

[jefo]

Yea it was pulling timing. And yes, I need to figure out whether the knock is false or not.

[jefo]

I talked to the tuner and he said the knock sensitivity was really conservative, and I'll get a new chip with a less sensitivity.

As a sidenote, the van ran a 13.82 at 101.3 mph today on the michelin defender's. 2.2 60ft. New personal best.

[wheming]

That mph is good for a lot better than 13.8! You got room to improve, which is always good.

[Vigo]

Nice improvement! I think there have been very few 8v vans in the 13s on street tires..

[jefo]

Yea when i get the 6 puck I have in there and put on the drag tires, it should put down some good times.

[jefo]

I ran the van with the new setup: lightly de-shrouded and port matched head with a 46trim stage 1 .63 turbonetics turbo. Also the 6 puck clutch. It trapped 95mph with the boost at 16psi and i turned the boost up to 24psi and it also trapped 95mph. So clearly there is an issue there haha. Time to check over everything and see what is causing the loss in power, as it trapped 101 with the stock garrett.

I'm thinking the valve springs on the different head could be too weak. I can't think of any other cause that would keep the power output the same when there is a big difference in boost levels. Air-fuel was good at around 11.5:1

Any ideas? It still pulls 21hg at idle like the older setup.

[moparzrule]

What intercooler and BOV are you running? Did you confirm no leaks on either?

[jefo]

I found the check engine light stopped working so it was detecting knock and pulling timing. I will still go through everything to make sure it is all 100% (including a boost leak test) and a new tune that is less sensitive to false knock.

It's a treadstone one rated for 700hp and a turbo-xs bov.

[moparzrule]

The Type H style BOV? Does it have washers for shims? If it hasn't been shimmed yet they only hold ~15 PSI on the spring alone before leaking.

I can't remember anymore, but have you tried a different knock sensor yet? Sometimes those things go bad.