No boost at the line

[87NAT]

What kind of gate do you have? I had an old deltagate that came with my 3" ATR DP. The old deltgate was shot. I took it apart and saw that it was not sealing completely...hence I could not make boost fast or set it at a steady max amount. Take it apart and look at the seat on the pipe and the gate valve itself. Also look at the shaft, it could be rusty and sticking not allowing free movement up and down. Bet either of those issues are your problem. I fought with my spooling issues for along time switching converters, chips, FP, chasing nonexistent exhaust leaks, boost controlling devices...etc.

I put a new tial WG and I get full boost (24 psi) at 50 mph in less than a frame on my PL. (1 second) I can also spool up my 6776 with my 2800 10" PTC to 6 psi on the footbrake in a couple of seconds on the street.

 

[GNRick]

What kind of gate do you have? I had an old deltagate that came with my 3" ATR DP. The old deltgate was shot. I took it apart and saw that it was not sealing completely...hence I could not make boost fast or set it at a steady max amount. Take it apart and look at the seat on the pipe and the gate valve itself. Also look at the shaft, it could be rusty and sticking not allowing free movement up and down. Bet either of those issues are your problem. I fought with my spooling issues for along time switching converters, chips, FP, chasing nonexistent exhaust leaks, boost controlling devices...etc.

I put a new tial WG and I get full boost (24 psi) at 50 mph in less than a frame on my PL. (1 second) I can also spool up my 6776 with my 2800 10" PTC to 6 psi on the footbrake in a couple of seconds on the street.

Damn!!!!!!!! That is exactly my problem! I'll take it apart and see what is going on. Thanks!

 

[JimP]

My boost issues were solved with two fixes. I had a pre-turbo exhaust leak, fixed that and was then able to hold 5 lbs. of boost before over coming the rear brakes which are still stock. I have a vacuum conversion, all rebuilt stuff from cardone. Prior to fixing the leak I would see 3,400 rpms and then the tires would break loose just as the boost gauge was about to climb.

I then added ss braided flex hoses and just changing that I can now hold close to 8 lbs. of boost. Brake pedal feels a lot better as well.

I could hear my exhaust leak and it was a pain to get rid of but spool up is almost instant now. Pre-turbo exhaust leaks very bad. Old deterioration brake flex hoses bad too. If your pushing your pedal to the floor and the lines are ballooning, that's less brake pressure being translated to the rear wheel cylinders robbing you of holding power.

See other mods in Sig.

 

[GNRick]

Damn!!!!!!!! That is exactly my problem! I'll take it apart and see what is going on. Thanks!

I took the wastegate off and can't really tell if anything is amiss. There is a lot of carbon on it but no rust. I would like to block off the pipes where the wastegate attaches to and slowly build boost. I'll know at 2500- 3000 rpm if I am on the right track. At least then I can tell if the wastegate is at fault or not. I can address the brake lines after that. Thanks for all of the good suggestions.

 

[GNVYUS 1]

I just saw that the ATR and Tial are swappable, if worse comes to worse you can come to my place and we can swap it out with my 38mm Tial and boost controller set for 24psi.

 

[GNRick]

I just saw that the ATR and Tial are swappable, if worse comes to worse you can come to my place and we can swap it out with my 38mm Tial and boost controller set for 24psi.

Sent you an email. Thanks for the offer, I may take you up.
I really want to get this thing solved.

 

[GNRick]

I took the wastegate off and can't really tell if anything is amiss. There is a lot of carbon on it but no rust. I would like to block off the pipes where the wastegate attaches to and slowly build boost. I'll know at 2500- 3000 rpm if I am on the right track. At least then I can tell if the wastegate is at fault or not. I can address the brake lines after that. Thanks for all of the good suggestions.

I inserted a plate to block off between the wastegate and the pipe it bolts on to. This should be like the wastegate sealing up the pipe, thus eliminating the wastegate from the equation. it made no difference. So now I am thinking, there is no gasket between the turbo and the ATR 3" downpipe. Could it be leaking there, and if so, is there a special gasket that would fit?

 

[GNVYUS 1]

Even if the DP wasn't on the car it wouldn't hurt the spoolup, actually some cars have a DP that goes from the turbo to the side of the front bumper at maybe 2 feet long so it's not that.

Can you post a pic of the wastegate/header setup and other engine pics, maybe there's something that will catch our eyes.

 

[GNRick]

Even if the DP wasn't on the car it wouldn't hurt the spoolup, actually some cars have a DP that goes from the turbo to the side of the front bumper at maybe 2 feet long so it's not that.

Can you post a pic of the wastegate/header setup and other engine pics, maybe there's something that will catch our eyes.

If I can get my camera to work with my new computer, will do.

 

[GNRick]

Maybe I figured it out. I bought a combo vacuum/boost gauge, to check the accuracy of the gauge in my dash that I was using. Vacuum starts out at 20 in/hg then as I power brake the vacuum goes to 0 and then to about 2 psi boost. So I am thinking.....do I have too much vacuum? Seems like if I had less vacuum, then gauge would move into the boost area quicker. Do I need a new cam? Engine builder put in a cam with stock specs. What do you guys think? If that is the problem can anybody recommend a cam? Thanks!

 

[GNVYUS 1]

Nope, it just means your cam is lame and you won't have issues with your vacuum brakes needing vacuum ( my GTO only pulls 10" of vac ).

You're not using the stock boost gauge right?

Just throwing crap out there but I can send you my Caspers cam sensor tool to make sure the Cam Sensor is dead on and not retarded etc. Slap the tape on the balancer, put on 0, plug in cam and it should light up.

Does the car rpm to say 5500rpm? I wonder if you have overtightened rocker arms and it's choking off lift etc.

Just throwing stuff out there.

 

[GNRick]

Nope, it just means your cam is lame and you won't have issues with your vacuum brakes needing vacuum ( my GTO only pulls 10" of vac ).

You're not using the stock boost gauge right?

Just throwing crap out there but I can send you my Caspers cam sensor tool to make sure the Cam Sensor is dead on and not retarded etc. Slap the tape on the balancer, put on 0, plug in cam and it should light up.

Does the car rpm to say 5500rpm? I wonder if you have overtightened rocker arms and it's choking off lift etc.

Just throwing stuff out there.

I am using a VDO boost gauge and also one I bought from O'Reilly's. Not sure of the brand but they both read the same. Car does go to 5500 rpm. Could I turn the cam sensor or do anything to it to adjust it?

 

[QUIP'6']

Maybe I figured it out. I bought a combo vacuum/boost gauge, to check the accuracy of the gauge in my dash that I was using. Vacuum starts out at 20 in/hg then as I power brake the vacuum goes to 0 and then to about 2 psi boost. So I am thinking.....do I have too much vacuum? Seems like if I had less vacuum, then gauge would move into the boost area quicker. Do I need a new cam? Engine builder put in a cam with stock specs. What do you guys think? If that is the problem can anybody recommend a cam? Thanks!

20 is awesome once you apply the brakes to build boost they are locked on if you had 10 inches then you would spin the tires quicker. you have great vacuum. i think you convertor nees tightening up a bit. i just went from a stock on a te60 to a pats 10 inch lockup 3200 and pats told me that it would spool to 3200 at 5 psi thats how he rates them. so when i am at o boost it is at 2400 rpm. so if you converter was tighter you would be getting in boost alot quicker. rpms doesnt build boost a load on the motor does. your motor has a light load on it at 3000 rpm than mine does. i would call them and see how they rate theres. btw with the stocker my te60 was a dog even when i spooled to 10 psi after i let go of the brakes. with this converter it spools faster than a stocker

 

[GNRick]

Any chance it could be the MAP sensor? I know the boost gauge gets it's vacuum from the line going to the MAP sensor. The exhaust consists of ATR headers, downpipe, etc. I've heard of the cat converter getting plugged. Could it be the cat. converter, causing too much back pressure? Thanks.

 

[QUIP'6']

Any chance it could be the MAP sensor? I know the boost gauge gets it's vacuum from the line going to the MAP sensor. The exhaust consists of ATR headers, downpipe, etc. I've heard of the cat converter getting plugged. Could it be the cat. converter, causing too much back pressure? Thanks.

no,no,no you need to look at your converter or get a transbrake if you are to leave that much stall in your converter

 

[GNRick]

no,no,no you need to look at your converter or get a transbrake if you are to leave that much stall in your converter

It is confusing because others say the stall is fine. Check this out:

http://www.turbobuick.com/forums/transmission-talk/260106-converter-stall-recommendation.html

I plan on putting on the stock intercooler to make sure I don't have a crack in my ATR front mount. Also, it has a welded on blow off valve. Could it be stuck open?

 

[GNRick]

Happy to report.........

I put on the stock intercooler and there is a definite improvement. I can get about 4 -5 lbs of boost now at 3400-3500 rpm. It seems when I power brake, however, the car starts to push at about 3000-3200 rpm. I had been able to hold the car steady up to 3400 rpm. Boost is maybe a couple pounds at that point. I was told that if I can make boost sooner, the brakes won't hold. He was right. So tomorrow I will remove the blow off valve and see what I can see. I looked at it and it is not welded on, like I stated in my previous post. Maybe I'll put a plate in there to block it off altogether. I'm hoping the intercooler is ok. Probably the front mount intercooler would give me a couple extra pounds of boost when powerbraking. When I first bought the car, I could hold 5 psi while powerbraking and my best 60' was 1.67.

 

[GNVYUS 1]

Cool, the ATR BOV should be a bolted on deal so I'd just ditch it for now and bolt a plate over it ( any gasket for that flange? ).

Now that you're building more boost the brakes have more torque they need to freeze to keep the car stopped. 3500 at 2psi is not the same at 5psi so you're seeing the limits of your vacuum brake setup not applying enough pressure to the cylinders. Check out how much the Powermaster guys can hold with your brake mods, some are over 15psi!!!

Try blipping the gas in neutral, when the boost gauge peaks on vacuum hammer the brake pedal. This will give you the best chance of holding that power on a vacuum brake setup for now.

 

[GNRick]

Cool, the ATR BOV should be a bolted on deal so I'd just ditch it for now and bolt a plate over it ( any gasket for that flange? ).

Now that you're building more boost the brakes have more torque they need to freeze to keep the car stopped. 3500 at 2psi is not the same at 5psi so you're seeing the limits of your vacuum brake setup not applying enough pressure to the cylinders. Check out how much the Powermaster guys can hold with your brake mods, some are over 15psi!!!

Try blipping the gas in neutral, when the boost gauge peaks on vacuum hammer the brake pedal. This will give you the best chance of holding that power on a vacuum brake setup for now.

I have a powermaster. :wink:

 

[QUIP'6']

changing to the stock intercooler just slowed down your spool up it did not improve your performance or boost at the line. the other cooler just spooled you up faster and pushed you quicker. the issue is the converter is way to loose throw a 2800 to 3000 and be done with it.