Charlie Robinson's '99 Riv

Vendors like ZZP aren't required to do recall "bad" parts they develop. They are required to refund or replace. I think sometimes the parts are perfectly fine, but they sell them for the incorrect application.

I'm sure there's a disclaimer somewhere, something like: "product descriptions are subject to change without notice." That covers incorrect application. And they can't be held liable for safety like OEM parts makers, because their parts are not subject to DOT certification. Many parts they sell are "for off-road/race use only." That covers safety claims.

Smaller companies like ZZP can't afford to guarantee everything works the first time, but I think they can do better. From what I've read and heard, I get the impression that if you don't come back with a claim, they're not going to bother letting you know about a problem - because they don't have to.

Karma wrote:

Wait... so they had "a batch of pushrods that we weren’t happy with." and a picture that clearly marks one type as "BAD" and yet they still sold them? and sold them recently?

I'd assume they posted that pic post investigation

My experiences with ZZP have been hit and miss over the years. I preferred to buy my stuff from Intense but they had minor similar issues. Seems like they are still in business. Just remember how small the 3800 aftermarket is. They end up having a lot of custom made or one-run parts batches.

Back with some scans.

here is where I left off with the 3.25". I was worried that I should be seeing more boost than ~7psi.
I am getting some decent timing with it and I think i will push it to see if I can get 20s @ WOT.
Problem I see is fueling tho. Running uber rich.
Actually. I think I fixed that in the 3.4" tune/scan you will see below. When I go back to 3.25" it should be ~11.4ish


Then I put the 3.4" back on and scanned. getting awesome timing @ WOT and , as expected, lost boost. Pushing ~6PSI with the 3.4. About a 1 pound difference from the 3.25". 3.4" feels like it launches as well as the 3.25 but the higher RPMS is AWESOME with the higher timing. I love it. First time the power has made my palms sweat.


I think from here I am going to go back to the 3.25" and dial in the tuning to get straight 20s with 0 KR and lean out the fuel until I see KR then richen it a bit to be safe.

I think 3.25" will be as far as I will take this set up for now.

Once gen V goes on this fall i expect to move back up to 3.4". Next year will be Headers and exhaust then end it all with a fat intercooler.

Dude your MAP kPa numbers make no sense and if that's what boost is being calculated from there, that's gonna be hosed up too. 100kPa is atmospheric (no net boost or vacuum) with 7psi, you would see something in the ballpark of 150kPa from the MAP. Your MAP sensor is reporting like 90kPa (which is still in the vacuum range) while pretty much WOT throttle making boost; What's goin on with that?

shoot. I have no idea. when i got the car back, i thought the MAP #s looked low but didnt think twice about it.

Your MAP parameter is reading Atmospheric pressure. On the DHP, there are 2 listings for MAP. There's BARO kpa, and MAP kpa. Baro is ALWAYS going to read atmospheric, whereas MAP is vacuum and pressure. My BARO parameter is usually locked in around 100kpa. MAP parameter is around 20 at idle, and I've seen as high as 182kpa at WOT.

I dont know why it wouldve changed. I will check it out.
putting this here for reference

Boost = MAP*14.695/29.921-14.695

Boost = (MAP*0.4912)-14.695

kPA * 0.14504 = PSI

Over 100
KPa Boost
10 1.4504
20 2.9008
30 4.3512
40 5.8016
50 7.252
60 8.7024
70 10.1528
80 11.6032
82 11.89
85 12.3284
87 12.618
90 13.0536
92 13.300
95 13.7788
97 14.100
100 14.504

That's about right. 182kpa puts me ~12psi, which is what my DHP reads. I think 12.1psi was the highest reading I saw.

I've never really seen a riv that had a baro sensor. Charlie if you look under da hood do you have two MAP sensors right next to eachother?

turtleman wrote:

I've never really seen a riv that had a baro sensor. Charlie if you look under da hood do you have two MAP sensors right next to eachother?

The MAP sensor is used to determine manifold pressure changes while the linear EGR flow test diagnostic is being run to determine engine vacuum level for other diagnostics and to determine barometric pressure (BARO).

Crazy isn't it?

So right now, he's reading BARO, not MAP. 2 different parameters based off the same sensor.

I figured the PCM just takes a sample from the MAP before the engine is started to get a base baro and uses it for the whole runtime. My car has no EGR but I still get a base baro number. I don't know how that would work. The exception is dual map cars (which is what I was wondering about if Charlie had that) that actually have a dedicated pressure sensor to constantly sample ambient pressure for mountain driving and stuff. There are 3800 cars that have that.

deekster_caddy wrote:

Sounds like the BBV is disconnected. Check all your vacuum lines. The T fitting under the SC snout can become brittle and break and then there is no vacuum to actuate the BBV. (Boost Bypass Valve)

Just got in from investigative reports.


Found a tear in my T ! Maybe this is the issue for my low MAP and boost #s?

Can these be had at any auto parts store?

charlieRobinson wrote:

Just got in from investigative reports.
Found a tear in my T ! Maybe this is the issue for my low MAP and boost #s?

Can these be had at any auto parts store?

Tear.....is it actually leaking? I've seen those things falling apart, but still sealed. That could explain the low boost #'s.

I haven't seen one at an AP store yet. All I can find is a plastic T made for rubber V-line to slip over, not vica versa. Even our "shop supplies" cabinet(s) doesn't have them, and they're unavailable. We always have to make some Mad Max lookin shit to replace it. Mine, as of right now, is glued and zip tied together. Works great

I think so. if i push on it slightly with the car running i can hear it hiss pretty clearly.
I tried the carburetor cleaner vacuum leak test but i couldnt hear the RPMs rising. So i dont know how much it the really affects the BBV or MAP readings or anything else.

From what i've read, the rubber female T vacuum piece is a legendary rare item and can only be found used or crafted. (I dont game, well not much.., but life is an RPG/game so I always reference when applicable) Otherwise, you must use a male T fitting and make it work from there.

I am looking up flexible filaments for the 3D printer and I just might print some vacuum fittings if the media works in this printer ok.

but for now, i might just do what everyone else does and just use electrical tape

charlieRobinson wrote:

but for now, i might just do what everyone else does and just use electrical tape

2-part Super Glue and a baby zip tie

+1 on the zip tie thing. I like to do it on any vacuum line I remove. It saved me when my T fitting split like yours did. Still holds true to this day.

Next time your have the lower intake off - perhaps when you do the new blower or IC, yank out that fitting and tap the hole with 1/8-27 NPT then put whatever you want on it and it'll be clean and not leak due to impossible to find vacuum fittings again. I was too happy once i finally did that. For now though yeah it's kinda just jerry-rigging something up to work. Before the NPT fittings I just had a combination of universal plastic/rubber fittings put together to make it work.

Here's some pics to show ya

I had a 1/8NPT male with two female ends and installed the barbed fittings for the hose going back to the map sensor and the one going up to the boost solenoid.


another shot

Recently I needed to change that tee out for a 4-way so I could add a pressure switch there which was no problem at all.

Good idea, Cody. Thanks.

BTW, what vacuum number are you guys pulling?  I am reading in PSI right now, not in/Hg, and I saw any where from -6 to -7.3PSI on the drive to work today. it was fluctuating pretty good.

Is 14.7in/Hg, what we should have? Would my valve train mods affect this?

-7.2 PSI = ~14.7in/Hg . So if i have less than that, I can be sure I have a vacuum leak, right?

There is a "Universal Vacuum Tee" in the Help section at most stores, but it's very very large. Try a Y fitting and a couple of rubber extensions and some zip ties as an alternative. Cody's plan is the best...

Weird. i checked the chart and it was using the sensor: MAP. I changed it to PID and the MAP values look like kPa now.


I can only seem to pack 7psi with the 3.25" pulley.

I dont think I can get 20 degrees of advance without gushing fuel or getting KR either.


So i can either get ~7psi with ~15 degrees of timing
or I can get ~6psi with 20 degrees of timing.

Need to go the track and test both tunes.

MAP is vacuum, or pressure, which is also boost. (+) values are boost. (-) values are vac. The engine doesn't have a boost sensor - it uses MAP to calculate. A vac leak will raise MAP value, especially at idle. If it's a bad leak, it could decrease boost, but I don't know how much.

Anything with a higher lift on it (your Cam) will change vacuum at idle, yes. That's why uber high-HP cars with crazy Cams need a separate vacuum pump. The engine produces almost no vacuum at idle and the engine wouldn't run without the external help. That's also why they tell you to raise the idle a bit when you install a Cam. Not only does it smooth out the idle (which sucks cause I love the lope), but it helps the lower vacuum numbers.

So i pulled both Ts (there are only 2, right?) 1 by the fuel rail and the under in the LIM under the snout?

The one by the fuel rail I already knew had a nasty gash. I patched that bad boy up with electrical tape.

I was shocked to find an even bigger gash in the LIM T.

I patched that one up as well and I am curious to see what effect this will have if any. the gashes were not wide open and the vacuum wouldnt be pushing them open from the insides but they were DEFINITELY not sealed tight.

I also switched back to the 3.4" pulley.

I need to get a wide band asap.

I am now pushing a hair over 7PSI with the 3.4"!!!

The leaks in the 2 T fitments were losing a pound of boost!

I wonder what the 3.25" would push now...!!!

i know I cant get the timing I want with the 3.25 so im not even gonna try.

But yeah, 7PSI with the 3.4 @ 20 degrees timing advance WOT

I am still trying to summon the courage to take the front valve cover off and pull a push rod for a pic.