Upgrading from pte 5831 mfs

[Brandon Burnett]

I normally search the threads before I ask questions on here, but here it goes.. I currently have a pte 5831 mfs on my 87' GN. My setup is a built tranny, ptc 2800 lockup, pte slic, alky, power plate, champion ported oe intake, champion ported irons, rjc bulletproof head gaskets (0.030 crushed), stock cam, lifters at 0.035" preload, roller button and double roller timing chain, ngk ur5s gapped at 0.032, 3" downpipe, 2.5" dual exhaust with cutout, TT chip, 60lb precision injectors and hotwired walbro 340. I am currently running 24psi and feel the bottom end is very strong, but it seems to peter out up top. I have been looking at upgrading to a pte 6262 cea. My hopes are it spools ok with the converter and it is ok to run with a stock cam. My goals are a streetable high 10 second car.

 

[AussieWE4]

What are you running for times now?

 

[Brandon Burnett]

What are you running for times now?

Atlanta Dragway closed for the winter November 9th. I broke the forward drum in my trans and rebuilt it, so my car was down for the last couple months. I may be able to ride to silver dollar and try and get a few passes in later. I was thinking about turning it up to 25-28psi and seeing what it dynoed for kicks so I could compare it to similar setups with a 6262. Hopefully it'll feel better up top with around 28psi.

 

[KEVINS]

I have pretty much the same combo and turbo. When I bought the turbo I was told it would be a good unit to run at 30psi or more with stock cam. At 28-30psi it's just starting to wake up on mine and at 33 there was a huge improvement on the street at 60mph. I'm running 35psi now with 87 octane and alchy but the high gear clutches are slipping now so no ET's yet.

At 24psi I doubt you're making it wake up so if it's nosing over I'd check something else.

ks

 

[Lil Truck]

I run a similar setup and found the valve springs on the champions got weak after the first year. At 5000 up the power fell off, I replaced them and it pulled hard past 5700. That is as hard as I run it. 26lbs 420hp/475Tq low 11s, stock IC 91/alky.

 

[we4Mateo]

I run a similar setup and found the valve springs on the champions got weak after the first year. At 5000 up the power fell off, I replaced them and it pulled hard past 5700. That is as hard as I run it. 26lbs 420hp/475Tq low 11s, stock IC 91/alky.

Nice! The small turbos really are a hoot on the street and strip. I agree with most above that it's probably something else if it's not pulling hard at that low of boost at the upper end. Fix the glitch and turn it up! Wire the gate shut and just run all the boost. You can do that on the smaller turbos. That's how I ran the times in my sig. Couldn't quite get 30psi out of it.

 

[Brandon Burnett]

Thanks for the replies. I think I'll try and wire the wastegate closed and see where it is. I think it may just be my perception on the top end. The last two cars I came out of were a 01' Z06 that made 540whp/580wtq shifting at 7000rpms and a 03' in cobra making 630whp. I wasn't sure if it was the cam causing the top end to feel weak, converter or I kind of went out of the efficiency range with the 5831 porting the head/intake. I only have about 600 miles on this setup. It runs flawlessly, but maybe I need to just jack up the boost. Kevin's, what are you using to control your boost? I have a HD actuator and rjc controller currently.

 

[Brandon Burnett]

Here are a few pics of it.

 

[KEVINS]

I've written some extensive postings on all my trials running a turbo at high boost pressures so if you get bored do a search on 5831 and you HAVE to treat the car with tender care when running as much as I am. The slightest lean issue can blow a motor. Do NOT wire the WG Closed with this turbo It will produce more boost than studded heads can handle.

The RJC controller is a simple Grainger Valve which is what I had but I made it myself before Jason was making them. It was NOT steady at higher boost levels at all so I tossed it in favor of the one mentioned below and I recommend it.

Another note. The wg puck kept getting blown open due to the pressure in the exhaust housing when running more than 26psi. I had to get an VERY strong spring to help the actuator hold the puck closed. The one I chose the first time would hold things steady up to 30psi but fluctuated above that. So I got an even HEAVIER one. Now it's rock steady at 35psi.

Another-Another note: Above 26psi my up-pipe would blow off the throttle body and when it did it destroyed my perfect hood liner. I fought this issue using different hoses, a multitude of clamps and NOTHING held it on. So I made a boost brace and that solved the issue. Do a search for "boost brace" to see pics. If you value your hood liner take it off until you KNOW the up-pipe will NOT come off with higher boost. My new one cost $700. OUCH!

Here's one of my postings:

Update:​

I got my boost control all figured out and I'm using this controller instead of my Grainger Valve and now the boost is setting at a steady 29psi with this turbo:​

http://www.turboxsparts.com/84.html​

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If you're wanting better boost control then I definitely recommend this unit although the instructions suck​

Turbo Review:​

When running this much boost the flapper valve was opening on it's own due to the pressure in the exhaust housing so I was told to put an extra spring on the WG rod. That worked perfectly. I did NOT open the wg hole any more than what it came with but I did blend the inside radius with a die grinder.​

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As far as the Precision 5831 turbo goes, I LOVE IT.​

Up to 22psi there is no difference in power over the stock turbo on my combo (stock long block) and there is a tad more turbo lag up to about 4psi but not much with a 2800 stall. Once it hits 4psi then the boost is instant. With a stock D5 it will feel the same so DO NOT let this little bit of lag deter you from getting this turbo.​

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When running 23-24psi you can really feel the difference starting to come through over the stock turbo.​

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At 25-26 psi the stock turbo can't keep up and the 5831 starts making real good power that can really put a smile on your face.​

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BUT, the fun doesn't begin until you hit 27psi. On my combo there is a huge difference between 26psi and 27psi that can really be felt and this leaves you wanting just a bit more. You can stop at this boost level and be perfectly happy.....if you want​

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At 28-29psi this turbo simply makes power! It feels like this is a very comfortable boost setting for this little hairdryer and this is where I am leaving it b/c the power this combo is making is just fantastic. It will light up the tires at 50mph at will and I need to feather the throttle to keep the tire spin controllable.​

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Yes, I've had it to 30psi and it feels very comfortable at this pressure on my combo but once you get to 28psi or more the car is making so much Stupid Power that it's just a waste of alchy on the street.​

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Oh yea, this is all on 91 octane and alchy​

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Thanks for all your help!​

Regards​

Kevin Slaby​

 

[Brandon Burnett]

It was actually your review that persuaded me to get the 5831. I do believe I will try and get a steady 28-30psi on my current setup and see how it feels. Hopefully soon I will have it on a Dyno and see what it puts down.

 

[KEVINS]

I really don't think you'll be disappointed if everything is tuned right. I'm shooting for 10's and I'm sure the power is there to do it right now but it will come down to the efficiency of the transmission/converter, gearing, tire diameter, etc... Just don't be scared of boost psi. Instead be TERRIFIED of detonation.

ks

 

[we4Mateo]

...Do NOT wire the WG Closed with this turbo It will produce more boost than studded heads can handle...

Boost is a measure of restriction at the TB. Cylinder pressure is what pushes on the heads. The above statement simply isn't true. I've run my TE44 with gate wired shut at 30+psi and I have stock heads with just bolts. No HG issues. My up pipe stays on just fine too with just a good clamp.

What mph have you run with the new turbo? That's more telling of head issues than boost psi.

Not trying to be a jerk. You've had unique issues that others don't seem to have.

 

[KEVINS]

Boost is a measure of restriction at the TB. Cylinder pressure is what pushes on the heads. The above statement simply isn't true. I've run my TE44 with gate wired shut at 30+psi and I have stock heads with just bolts. No HG issues. My up pipe stays on just fine too with just a good clamp.

What mph have you run with the new turbo? That's more telling of head issues than boost psi.

Not trying to be a jerk. You've had unique issues that others don't seem to have.

I know you're not being a jerk. and you're correct; I've had issues that few people have had (story of my life) but none-the-less I have had them and went to great pains to correct them (three different types of clamps and two types if different hoses that people have recommended with no luck) but if my issues give others an idea of what may happen then they can choose to take steps to prevent experiencing them themselves or an idea of how to fix them. Approximately 10-15 people have actually contacted me b/c they can't keep their up-pipes on either so I give them the p/n's I used to make the brace themselves. I'm not the only one having this issue but I seem to be the only one posting about it.

I don't know where your boost is measured at but mines measure at the manifold so this is the holding tank for air that I'm measuring.

My stock turbo was wired closed to and the max boost I could get out of it was 24psi b/c that's all the air it would pump out on my combo. Your TE44 must have been the same way with your combo if it was wired closed. What I'm saying is don't wire the WG closed b/c this turbo may spike to 50psi of boost and if that extra air DOES get into the cylinders then that extra cylinder pressure may cause some major cylinder pressure creating a larger "bang" which may find it's way between a gasket and sealing surface not to mention possibly causing a lean condition and hurt parts real quick. If he wants to sneak up on wiring it closed I'd really like to hear how much it does produce and the ET's it produces

No ET's yet b/c high gear is slipping in the tranny so I'm saving for a Stage II from Extreme Automatics. Once I start running it I'll get to see where the turbo starts to fall off at the track. I'm well aware that this turbo may not be efficient at the track at 35psi but on the street the ability to light the tires up at will at 50mph (30psi) or 60mph (33psi) shows promise that it does like short bursts of high boost.

KS

 

[Dusty Bradford]

The problem is the valvesprings and/or the cam. Good springs will allow it to pull to 5200-5400 at best. You need more cam to get into the 5600-5800 range. Stay on top of the spring pressure also. Its not unusual to need springs every year to keep the flat tappet cams working. A roller cam which can operate at higher spring pressure would be a nice upgrade.

 

[Brandon Burnett]

Well, I took it into work today and removed the rjc boost controller. I installed my old nxs brass boost controller. I've taken both apart noticing the rjc ball and spring were smaller/weaker. I have already seen several people installing them by the instructions and only seeing 24psi maxed out. I took apart the $19.99 nxs boost controller and noticed the ball was bigger and spring was stiffer. The bleed hole on the nxs was also larger than the rjc. I installed two tandem throttle cable springs on the wastegate and first test pegged out over 30psi. I eventually got it down to 28-29psi. It seems better, but it haven't had a chance to do a full pull through all the gears. No knock through the the gear, but there always seems to be 1.7-2.1kr when I hit the gas rolling, i think it is false knock though. The initial knock seems to always be the same number when boost is set to certain levels. At 24psi it would always be an initial 1.7kr and then go to 0.0 through the rest of the gears. At 28-29psi the initial kr is 2.1 and then goes to 0.0 shifting through the gears. I'm not sure if I am the only one that has noticed a linear path related to initial kr and boost or maybe just a hiccup in my setup, exhaust rattle, etc.

 

[KEVINS]

Yea, I fought knock when rolling into it also. I'd have to roll into it very slowly to eliminate it. If I stab the throttle quickly then I get it even sitting in the driveway at an idle. I don't know if it was linear tho..

ks

 

[Brandon Burnett]

Yea, I fought knock when rolling into it also. I'd have to roll into it very slowly to eliminate it. If I stab the throttle quickly then I get it even sitting in the driveway at an idle. I don't know if it was linear tho..

ks

I have the same thing going on. I can roll into it like you said with no knock, but when stabbed I have a little and it always is the same number. I think it may be something to do with the sudden blast and the motor rocks. I've done the knock checklist with no luck. I have adjusted te alky and the o2 will change from 760-830 and it doesn't seem to help. I have deemed it as false knock. I have a rjc bell housing brace on the back and torque strap up front with factory new motor mounts. I've adjusted the initial and turnon in the alky box also and hasn't helped.

 

[KEVINS]

I have the same thing going on. I can roll into it like you said with no knock, but when stabbed I have a little and it always is the same number. I think it may be something to do with the sudden blast and the motor rocks. I've done the knock checklist with no luck. I have adjusted te alky and the o2 will change from 760-830 and it doesn't seem to help. I have deemed it as false knock. I have a rjc bell housing brace on the back and torque strap up front with factory new motor mounts. I've adjusted the initial and turnon in the alky box also and hasn't helped.

Despite what all the electrical/computer gurus say I still think it's the computer not knowing what to do with the quick voltage changes + MAF + ?? + ?? that causes it.

It is false knock no doubt, at least on mine. I made several passes and recorded the KR. Then I welded up the motor mounts and duplicated the passes and the KR looks identical as the previous passes. I even get the exact same pattern sitting in the driveway and simply stabbing the throttle at just above an idle. I then broke the welds back off the motor mounts and repeated the process and it recorded the same pattern. It did it with the stock turbo and this new one.

ks

 

[V6POWER]

KEVINS--How much timing? What is your target afr? Thanks.

 

[KEVINS]

KEVINS--How much timing? What is your target afr? Thanks.

No clue on either one. It's a TT chip setup for alchy and high boost (if that even makes a difference) and I don't monitor AFR.
ks