boost question
#1
Registered User
Thread Starter
Join Date: Aug 2007
Location: vancouver canada
Posts: 21
Likes: 0
Received 0 Likes
on
0 Posts
boost question
I just finished installing a ht3b and hx35 I have an edge with attitude and the gauge on that reads 41 lbs max. It read that with the stock turbo as well. I've tried pinching the line to the waste gate off and the still reads 41. I know i'm getting more because my egt's went down. Has anyone seen anything higher than 41 with an attitude moniter?
#2
Registered User
Join Date: Jun 2007
Location: Alaska
Posts: 341
Likes: 0
Received 0 Likes
on
0 Posts
The monitors that connect to the MAP sensor are not going to give an accurate boost reading. You need to monitor actual boost with a gauge that reads the boost PSI directly. The MAP sensor only reads up to around 40 - 45 PSI even if you are pushing more.
#3
DTR 1st Sergeant
^^^^ what he said. Especially when your module is doing boost fooling to the ecm so it will purposely read a lower figure. That is the one problem with digital gauges... you never know when you are getting the straight dope on something. I recommend getting a mechanical boost gauge for accuracy. Mount using a boost bolt in the intake manifold or tap into the intake horn. Also, I have the same twins... the edge with attitude alone may not be enough fuel to spin those twins to your satisfaction. Enough fuel and you can hit 65psi. So be careful you don't blow a head gasket! Please fill out your sig so we can help you better.
#5
DTR 1st Sergeant
As far as a direct answer to your question, there are many paths to get there, some dependent on the year truck you have. There are many opinions here to. Remember that is all they are. Doesn't mean they are right, doesn't mean they are wrong, just what they have experienced. All these trucks seem to respond differently to the same things too.
That said, for your setup I would recommend a Smarty for the downloader. Stack it with a good module. Take your pick. A pressure only like a MP-8 or quad xzt is a good start. Or a TST which right now may be the best stack with Smarty (IMO). I am personally waiting for the new quad x2. From there you will need a stronger lift pump than stock to keep fuel to the cp3. Something like FASS or the walbro is popular here. But there are other options as well. Beyond all that-- a modified cp3 and while not necessary, but helpful, a nice set of towing injectors (say 45-75 hp range). If you can do all that, you may have a very dependable, nice towing, yet 600 hp truck!
#6
DTR 1st Sergeant
Sorry, I see now you did fill out your sig... my bad...
I'm not a big Edge fan, but since you already have it, some of the others here that use edge w attitude can advise on what stacks well with it. You already have FASS, so cp3 mod is next. At your level you can probably get away with the DIY mod (I did) or get a stage 2 cp3 from someone. That should get you to where you want to be. After that is the injectors if you want more.
I'm not a big Edge fan, but since you already have it, some of the others here that use edge w attitude can advise on what stacks well with it. You already have FASS, so cp3 mod is next. At your level you can probably get away with the DIY mod (I did) or get a stage 2 cp3 from someone. That should get you to where you want to be. After that is the injectors if you want more.
#7
DTR 1st Sergeant
I just finished installing a ht3b and hx35 I have an edge with attitude and the gauge on that reads 41 lbs max. It read that with the stock turbo as well. I've tried pinching the line to the waste gate off and the still reads 41. I know i'm getting more because my egt's went down. Has anyone seen anything higher than 41 with an attitude moniter?
One very important thing to keep in mind is that the quality of boost is much better with your twins and at the same boost level you are getting more air and cooler air which results in lower egts. The reason is the stock turbo had to really work hard to get that amount of boost and that much compression of the air results in a lot of heat. Hot air is lighter air... not as dense... not as good.
Simply put: stock turbo at 40psi is putting substantially fewer air molecules into the cylinder at a much higher temperature than twin turbos working half as hard each. The twins can be at the same psi boost but adding a lot more air. You see that on your egt reduction.
Trending Topics
#8
Registered User
Thread Starter
Join Date: Aug 2007
Location: vancouver canada
Posts: 21
Likes: 0
Received 0 Likes
on
0 Posts
so you think a modified or stage 2 cp3 should go on before the injectors?How is yours off the line for lag, mine is pretty sad till i get going. My stock turbo didn"t have this much lag.
#9
DTR 1st Sergeant
I would go stage 2 cp3 before injectors if you have a good electronic stack going.
What size exhaust housing do you have?
#10
Registered User
Thread Starter
Join Date: Aug 2007
Location: vancouver canada
Posts: 21
Likes: 0
Received 0 Likes
on
0 Posts
You will have more lag than stock... the way it is. To have the best of both worlds the stock turbo is used on the top but then you are limited on total HP support and there can be backpressure issues too. Can't have it all.
I would go stage 2 cp3 before injectors if you have a good electronic stack going.
What size exhaust housing do you have?
I would go stage 2 cp3 before injectors if you have a good electronic stack going.
What size exhaust housing do you have?
#11
DTR 1st Sergeant
#12
DTR 1st Sergeant
I am going to see if I can't sent the top in and have it changed to a 12cm housing. That will help a little on the bottom with some loss on top. I think...
#13
^^^^ what he said. Especially when your module is doing boost fooling to the ecm so it will purposely read a lower figure. That is the one problem with digital gauges... you never know when you are getting the straight dope on something. I recommend getting a mechanical boost gauge for accuracy. Mount using a boost bolt in the intake manifold or tap into the intake horn. Also, I have the same twins... the edge with attitude alone may not be enough fuel to spin those twins to your satisfaction. Enough fuel and you can hit 65psi. So be careful you don't blow a head gasket! Please fill out your sig so we can help you better.
There are digital gauges that still use regular electronic boost/pressure/temp sensors. I would put my SPA gauges up against any mechanical/analog gauge when it comes to accuracy and response times.
I think what Soulezoo was getting at is that you don't want a gauge/monitor that simply uses the stock boost sensor. That sensor is being "fooled" by the module/programmer and won't read accurately. As you've already found out too, they don't have a high enough range to read accurately with a bigger single or twin turbos.
#14
YOU CAN DO IT!!!
#15
DTR 1st Sergeant
Have them send you the housing and just do the swap yourself. I haven't messed with a 3rd gen turbo, but it was cake to swap housings on my 1st gen HX-35. The turbo should be easy to remove since it's right there on top and you don't need to screw with the downpipe or anything. This way your truck isn't down for days/weeks.
YOU CAN DO IT!!!
YOU CAN DO IT!!!