Adjusting the IP to match the Holset

[burn_your_money]

Good to hear you have it at a more acceptable level now. I'm also interested to hear what you have your timing set at.

[Gizmoman]

On my holset setup I cannot throw enough fuel to it. The more aggressive you get with it the more boost it makes and in turn I will actually see the egt raise to almost 800f and then come down. I have mine turned all the way up and the pump timing set .94 and I cannot get past 800f. If I baby it the egt stay around 750f...what kind of RPM are you running to get the egt? Do you have a manual boost controller?

I'm not sure of the exact RPM as I'm watching the EGT numbers. My guess is 35-3800.
I have no boost controller because the wastegate is physically wired shut. I did that because I couldn't get over 16 and was loosing my patience. The most I have ever seen is 21 lbs but again, Giles tuned the pump for a K14 at 14 psi max (as I instructed him to do). Also, the pump is from a 1.6. Not sure why the PO did that but that's what was on it when I bought it. Giles said the 1.6 pump would work fine for my needs but again, that was before I went to the Holset.
Theman, I know you built a very nice intake. Do you think the one I built above may be restricting the air?
I don't remember where my timing was but I bought one of those tools that uses a pulse signal (suggested by Andrew Libby) and hooked up a timing light. All I can remember it was at the recommended setting - again by libby.
It starts instantly after the glow plug light goes out  if that tells you anything.
I could look back at those post several years ago and see if I can find the conversation.

EDIT - I did a search and found that my final setting for the timing was .95mm.

[burn_your_money]

0,95mm sounds good. If you feel like chasing low probability possibilities, check for air in the feed line while the EGTs are maxing out. Air in the fuel may be causing the dynamic timing to cut back some.

[Gizmoman]

0,95mm sounds good. If you feel like chasing low probability possibilities, check for air in the feed line while the EGTs are maxing out. Air in the fuel may be causing the dynamic timing to cut back some.

Interesting. Not sure how I'd check that but I do have an inline pump that I could turn on and see if it changes anything.
I may tale it to work tomorrow just to take it for a good run. Ill report in when I get home.

[Gizmoman]

The drive to work was much better than usual as I have several 3% grades. One is on the freeway typically at 70 MPH(3400 RPM). The other is on the way home and is a 3rd gear pull as its a residential street. Boost is coming on sooner and 1200 F is hard to reach (used to be easy). Had I not backed out the fuel screw, I doubt I'd ever make it to 1200 but I added a bit of fuel during my adjustments as a compromise because it has always been sluggish at the bottom end. Now I have good bottom end, lower egt's and higher boost. I still don't understand why I cant reach 30 PSI like theman with his Holset but it's probably because I don't get the fuel/boost concept entirely

Looking forward to the rebuilt 5 speed with the closer gears and feel better now about raising the final from 0.86 to 0.78.

Thanks for everyone's help - this is still my favorite forum.
Jim

[theman53]

On my holset setup I cannot throw enough fuel to it. The more aggressive you get with it the more boost it makes and in turn I will actually see the egt raise to almost 800f and then come down. I have mine turned all the way up and the pump timing set .94 and I cannot get past 800f. If I baby it the egt stay around 750f...what kind of RPM are you running to get the egt? Do you have a manual boost controller?

I'm not sure of the exact RPM as I'm watching the EGT numbers. My guess is 35-3800.
I have no boost controller because the wastegate is physically wired shut. I did that because I couldn't get over 16 and was loosing my patience. The most I have ever seen is 21 lbs but again, Giles tuned the pump for a K14 at 14 psi max (as I instructed him to do). Also, the pump is from a 1.6. Not sure why the PO did that but that's what was on it when I bought it. Giles said the 1.6 pump would work fine for my needs but again, that was before I went to the Holset.
Theman, I know you built a very nice intake. Do you think the one I built above may be restricting the air?
I don't remember where my timing was but I bought one of those tools that uses a pulse signal (suggested by Andrew Libby) and hooked up a timing light. All I can remember it was at the recommended setting - again by libby.
It starts instantly after the glow plug light goes out  if that tells you anything.
I could look back at those post several years ago and see if I can find the conversation.

EDIT - I did a search and found that my final setting for the timing was .95mm.

I remember your intake a little, it could be restrictive. Do you have a stock intake that could be easily swapped to see if there is any change? Or take yours off and have it flow tested?

[Gizmoman]

I remember your intake a little, it could be restrictive. Do you have a stock intake that could be easily swapped to see if there is any change? Or take yours off and have it flow tested?

I don't have another intake and if I did, it would be tough to plumb my turbo to it at this point.
Here's another shot of it. . .


I think I have it modeled in Solidworks and could probably do a flow test on that. Do you know what flow numbers I would use? The software will only test one input and one output at a time but then, that's the way it works anyhow .

I still need to do a pressure test of my boost system. I have made a plug to insert into the intake and will put 20 PSI to it and check for leaks this weekend. I was running hard next to a concrete barrier the other day with the window rolled down and I swear I could hear a hissing noise while I was boosting in the high teens.

[RabbitJockey]

i think there must be a boost leak, you have a larger engine and smaller turbo than theman53.

[libbydiesel]

Nice to see you on here Jim and also good to hear the van has been running well.  I think the AAP will be a nice upgrade.  I also think the .77 5th will be a good choice considering the rest of your setup.

[Gizmoman]

i think there must be a boost leak, you have a larger engine and smaller turbo than theman53.

Yup - boost leak.
I made a fitting and plumbed a regulator set to 30 psi and installed it into the intake before the WAIC.
Sure enough, I had two leaks, one at the turbo outlet, and another at a 30 degree fitting. They were small but noticeable after I sprayed some Mr Bubble mix on em.
I took it all apart and inspected the silicone fittings - no cracks. However I don't think I had the clamps properly set over the bumps on the turbo or the elbow. I re-fitted everything and checked it again.They are fixed now and I took it for a run on the freeway. Egt's seem to be running about 200F lower than they were which is fantastic but I can still get to 1200F if I tromp on the pedal and hold it for a bit (which I expected).
What gets me is I can only hit 20 psi max. As soon is it gets to 20 it drops off to 11 or 12 (like hitting a light switch) and feels like its running out of fuel. If I back off the stumble quits.
It doesn't get to 20 and sit there - it immediately drops to 11 psi. Keep in mind, I have the waste gate wired shut.
I suppose if Giles built it for a K-14 possibly it can't fuel enough to make the Holset boost over 20. Now that the leaks are fixed though, I am hitting higher numbers easier and quicker than I was.

I'm still perplexed what the stumbling is and I don't know enough about the pump to know if there's anything that can be done. Maybe its something as simple as a cruddy pick-up screen in the tank. This thing is 35 years old and I have no idea what the inside of the tank looks like.

I should mention that my fuel lines are clear and I see no bubbles (at idle anyway). Also, I have a 12 volt diesel pump inline which I can turn on and off from the dash. I made several test runs with the pump on and pump off - no difference.

Nice to see you on here Jim and also good to hear the van has been running well.  I think the AAP will be a nice upgrade.  I also think the .77 5th will be a good choice considering the rest of your setup.

Good to hear from you as well libby!

Any suggestions from the group as to what could cause this stumble at 20 PSI would be appreciated.

[libbydiesel]

I'm not sure. Does it happen regardless of rpm?  In other words, if you are cruising along at the top of 3rd gear do you get the stumble at 20psi the same as if you are accelerating from the bottom of third?  What is the history of your valve springs?  Maybe something like high exhaust pressure is pushing open the exhaust valves and giving a nice dose of EGR? 

One option is to consider a well-fueled 18 psi decent abuse on a vanagon trans and solve the 20 psi stumble by limiting boost to be below that. 

[Gizmoman]

I'm not sure. Does it happen regardless of rpm?  In other words, if you are cruising along at the top of 3rd gear do you get the stumble at 20psi the same as if you are accelerating from the bottom of third?  What is the history of your valve springs?  Maybe something like high exhaust pressure is pushing open the exhaust valves and giving a nice dose of EGR? 

One option is to consider a well-fueled 18 psi decent abuse on a vanagon trans and solve the 20 psi stumble by limiting boost to be below that.

Point well taken. The tranny I have has served me well and I hate to thrash machinery. However, I need to see what this thing can do and I'd rather do it with this one than the new rebuild. I very seldom put the pedal to the floor and don't intend to do so with the new transmission. However, ever since the rebuild of the motor, I've had this feeling that I'm missing something. It just feels like its struggling more than it should - hard to describe.

20 Psi is a rare beast and only shows up for a split second when I'm really into it so, no, it only happens when I hit between 18-20 psi.

I have a "tiny tach"which works well but not too good for a quick glance I'm guessing RPMs are probably in the 35-3800 range at that point. It then stumbles immediately dropping to 11 PSI - I back off, and all is well again.  This morning on the way to work it did do something it has never done - it felt like the turbo had just quit or I was running out of fuel. I was doing about 55 or 60 and when I gave it even a small amount of fuel, it just went flat - did this several times at ever bump of the pedal. I immediately headed for the nearest exit and when I got off, it was fine. It took a few blocks to find my way back to the freeway and it never happened again. It is still doing the 20 psi stumble and it must have something to do with the major increase in tension of the star-wheel spring as that's about all I've changed (last weekend).

Maybe now that my boost leaks are fixed, I should back the spring off?

7 psi is cruising at 60-65 so it's not that big of a deal. I'm just trying to find the limits and they seem to be much closer than I think they should be. That said, Theman's 1.6 has some serious porting and other mods and his car probably weighs half as much as my van. It's certainly more aerodynamic . Pitting his 30 psi and 800F Egt's against my brick is not a good measure.

Oh, as to the valve springs, the head is was a brand new Kolbenschmidt, I believe there's not much chance of an issue but I spoze anything is possible.

As I'm writing this, I recall that the Tiny Tach may record the highest RPM, I'll do some checking and see if I can get it to reveal itself. Possibly I'm floating the valves without realizing it.

[burn_your_money]

When it's stumbling, what happens if you just hold your foot to the floor? Does it resolve or does it just stay in "limp mode". What happens to your EGTs?

Another left field thought, are all 4 mounting bolts for the pump secure?

Lowering the spring tension in the LDA may help your problem, or turning up the max fuel screw.

PM sent

[Gizmoman]

When it's stumbling, what happens if you just hold your foot to the floor? Does it resolve or does it just stay in "limp mode". What happens to your EGTs?

Another left field thought, are all 4 mounting bolts for the pump secure?

Lowering the spring tension in the LDA may help your problem, or turning up the max fuel screw.


PM sent

When it stumbles, I back off immediately and I've quit trying to hit 20 psi till I figure out what's going on as it sorta freaks me out.

All four screws are in excellent shape and as reasonably tight as I can get them with a big screwdriver.

I have the spring pretty tight at this point and may back it off in the morning. I think I'm making too many adjustments at the same time and need to be more methodical about this as I move forward. The one good thing that has come of this so far was the suggestion to look for boost leaks. I found two small ones and now they are fixed lowering my EGT's about 200F across the board.

I should add that during my 30 PSI test into the intake (after I fixed the two bubbling leaks), I could still hear air. As I did some extensive welding on the intake, I may have a leak at one of the ports but it's too hard to reach and check. I'm sure I checked the surface for flatness before I installed it though. Possibly I needed to roll the engine to TDC to keep from blowing past the valves as that's probably all I am hearing now.

Open to any and all suggestions and appreciate the feedback. I'm not one to give up, just don't know what direction to take at this point.

[burn_your_money]

All four screws are in excellent shape and as reasonably tight as I can get them with a big screwdriver.

I mean the ones you would loosen to adjust the timing.