Gillis valve installation

[Tooltime]

Just a quick question. After I installed the gillis valve I took the car out to dial in the boost. It works fine, I started low and worked my way up, But it seems to be missing something power wise. Is that because I have a stock fuel pump? At one point I had it up to 18 psi and it stumbled so I took it back down. But thats with the stock guage. Any thoughts?

[indiana dave]

If it was 18 on the stock guage, it very well could've been boosting higher.
Also, I wouldn't boost much higher without a bigger fuel pump and an adjustable fuel pressure regulator.
35# injectors don't hurt either.
The higher boost could also be blowing the intercooler hoses apart. Tighten the clamps and if they don't hold, go to a semi-truck supply shop and get some heavier-duty clamps.

[Tooltime]

Thanks Dave, I've got an 86 so I do have #35 invectors, but I was worried about the stock guage not being accurate. I'm getting the car ready for Putnam.

[indiana dave]

Speaking of Putnam...
That's where I discovered that prolonged 18psi of boost is too much for hardware store hose clamps.
I spent all of Sat. pulling into the pits to tighten or reattach my intercooler hoses.
Sunday I showed up with yellow cinch straps holding my intercooler in place! It might've leaked a little boost, but at least it stayed together.
We've never had more than one SVO at our event. RSchonegg and I will probably both be there this year.
Glad to hear you're going to try to be there!
We'll have a blast!
Well, we kinda got off on a tangent, so PM me if you have any questions about it!

[WaltM]

Re: Gillis valve installation

Originally posted by Tooltime
Just a quick question. After I installed the gillis valve I took the car out to dial in the boost. It works fine, I started low and worked my way up, But it seems to be missing something power wise.

I have the same problem. I'm only at 16lbs but it I believe that it should feel stronger. Am I missing somethinig?

[8T6 SVO]

Re: Re: Gillis valve installation

Originally posted by WaltM
I have the same problem. I'm only at 16lbs but it I believe that it should feel stronger. Am I missing somethinig?

Your both probably feeling the effects of "pulled timing".

Put some race gas in and try it again.

[WaltM]

I dont mean to sound too dense, but I'm still learning.

What's "pulled timing"? When you say race gas, do mean premium or an octane booster?

Like I said, I'm still learning.

[SVOBart]

It means that the EEC is retarding timing based on input from the knock sensor. You could probably unplug it when running at the track, just keep your ears open for detonation.

[WaltM]

Would advancing the timing 10-12* produce the same result?

[SVOBart]

I'm not sure if I'm following you here. Are you talking about setting the initial timing at 10-12 degrees BTDC or advancing the timing another 10-12 degrees beyond 10 degrees?

EEC adjusts spark timing from the base timing based on a number of factors such as engine load, engine temperature, etc.

If it feels like the car is down on power at full boost, do a basic tune up first, drive around for 4-5 warmup and cool down cycles and the pull the plugs to look for signs of a lean or rich mixture, detonation, or some kind of fluid contamination (oil or coolant). With a little practice you can make a decent diagnosis of what your problem may be just looking at the plugs.

Bart

[WaltM]

Right now, the car is set at factory spec 10* BTDC w/new plugs, wires rotor and cap. As far as performance is concerned, it just doesnt have the same "seat of the pants" feel it had before the valve was installed. My other option would be to go back to the stock BCS.

I guess I'll mess w/it and see what happens

[SVOeric]

I really wouldn't unplug the knock sensor. as long as everything is working ok, it's saving you from replacing a head gasket (or worse)

[indiana dave]

Just try this.

Unplug the knock sensor. On our older cars, it picks up too many normal rattles, and mistakes it as spark knock. Use common sense though. Don't run hard with the radio loud and listen to your engine for knock when pushing it hard.
Mine was picking up rattles, and retarding the timing. I unhooked it years ago. I hardly listen to the radio anyway, and always keep my ears open. I also use premium gasoline, and add octane booster when running hard at the track. Generally I don't drive it too hard around town, so booster isn't necessary.
Also, both of you might have weak fuel pumps... Are they the originals? Is your fuel filter clogged?
There are many things to check.
I'd search this site anddig up all you can.

[SVOeric]

umm -- fix the rattles..

[WaltM]

I'll work with the timing and the Gillis valve before I start disconnecting any sensors.

I'm not taking the car to the track, but I don't want to be humiliated by an Eclipse with a trashcan muffler either.