Looking for a LT4 log with SCIAP Vacuum and Pressure in the channel list.

[GPGTP]

just got my SCIAP wiring harness. I assume you guys are using a mounting bracket with a male vacuum port to attach the 1 bar remotely. Does anyone sell one or know of one that works with the factory 1 bar? Thanks in advance.

[crankz1]

just got my SCIAP wiring harness. I assume you guys are using a mounting bracket with a male vacuum port to attach the 1 bar remotely. Does anyone sell one or know of one that works with the factory 1 bar? Thanks in advance.

This was posted by another member on a different thread.

https://www.vaporworx.com/shop/produ...nting-bracket/

[Ben Charles]

You could use the above or T into a vac line going to snout.. I chose to use the right drill bit size for the 1 bar map and mount it that way (cleaner look in my opinion)

[GPGTP]

Thanks for the replies. I found a few blocks on the google machine that look decent, I?ll probably go with one of those. I was considering removing the snout and tapping to add another port but I remember it?s kind of a pita to remove so I?ll probably tee into the pcv line. So the SCIAP wiring kit say I only need to change the map type settings switch but I?m sure I need to adjust the linear and offset for the sensor as talked about previously in this thread. Since I don?t have those ?tables? for my car I?m assuming I?ll need to have support add them. I?m definitely considering getting a smooth boost as well but there are a few unknowns and bugs I?m sure. Idk if I want to invest in that if there are still bugs/ things that haven?t been figured out when adding it. Wouldn?t it be great if hptuners released an OS mod for us to apply to run the LT4 OS? I?m sure it there is a ton involved in doing so, stuff way beyond my level of knowledge.

[sandworks]

I just triple checked my instructions and they are showing correct with above diagram. I even found the schematic I used when I made the kit/ wrote the instructions.

Its very possible the customer made a mistake. Its easy to do moving wires around.. and while this is easy to do it would also be easy to make a mistake.

Here is the schematic I used when I wrote it.. I back to suspecting only 1 pinout for GEN 5 until proven otherwise.


Attachment 133202


The schematic is easy to write instructions for because the LT4 pinouts are listed right where the LT1 pinouts are + add the pinout for sciap. This sorta dates our kit too.. I got that diagram in 9/2022. All of the PD blowers done here since then have gotten the kits (4 I think) and have all worked out like we expect. The only time I had it not work is when I tried to use a GEN 3 1 bar map sensor as a SCIAP because the vacuum nipple they use would have been easier to use mechanically than the bolt in style MAP sensors that have that o-ring nipple.




Side note.. we also sell plug and play fan kits. Weekly we deal with people who installed it "correctly" and "triple checked wiring" and spoiler alert.. its always the installer making a mistake.

I will say that the instructions for this sciap was wrong on my truck, I tried to talk to you Alvin but all I got was you are wrong. Good customer service.

[GPGTP]

I will say that the instructions for this sciap was wrong on my truck, I tried to talk to you Alvin but all I got was you are wrong. Good customer service.

What exact was allegedly wrong and do you think it is a matter of difference between the trucks and the passenger vehicles?

I?m trying to make sense of exactly what I need to make this function properly. What I?ve gathered so far is once I pin this out I need to change the map to SCIAP and change the linear/ offset once hptuners maps it for my os. I thought support would have added the linear and offset tables for the new beta but I was wrong.

Do I need to change/ add anything else for ideal results? Any feedback is welcome and appreciated.

[GHuggins]

There's another thread on here that has the pin outs wrong. As long as you use what I posted with the schematics you'll be fine.

There is another setting that we don't have access to if you want things to be 100% functional. My coder informed me of this and I can not take credit for it, but there is a sciap smoothing factor that needs to be changed too. This will keep baro codes from being set and keep the baro 100% functional. It may do other things too, but I'm not sure. You can work around this by not switching the pressure switches how they need to be but again not 100% correct.

If you're doing this to a car - this is where things differ because car and truck setups are different, which I don't believe is ever discussed - you can add the lt4 map, set to supercharger equipped and wire in the temp sensor straight to the ecm. Can't do that on the trucks as they use the temp sensor pin for an ambient temp sensor input. So if you have a car you can have a nicer setup all around.

[GPGTP]

There's another thread on here that has the pin outs wrong. As long as you use what I posted with the schematics you'll be fine.

There is another setting that we don't have access to if you want things to be 100% functional. My coder informed me of this and I can not take credit for it, but there is a sciap smoothing factor that needs to be changed too. This will keep baro codes from being set and keep the baro 100% functional. It may do other things too, but I'm not sure. You can work around this by not switching the pressure switches how they need to be but again not 100% correct.

If you're doing this to a car - this is where things differ because car and truck setups are different, which I don't believe is ever discussed - you can add the lt4 map, set to supercharger equipped and wire in the temp sensor straight to the ecm. Can't do that on the trucks as they use the temp sensor pin for an ambient temp sensor input. So if you have a car you can have a nicer setup all around.

Thanks for the reply. Is this the schematic you are referring to?

lt4 schematic.jpg

The vehicle in question is my 18 SS with 2650 Maggie. So, my blower kit came with a harness that breaks out the IAT, originally in the MAF. So, correct me if I'm wrong but from what I'm gathering, you are suggesting I put that IAT back in the MAF. Then remove my LS9 map, install the LT4 map, change the map connector to LT4 4 pin, and run the IAT wire to the ECU pin X1 13. Did I interpret that correctly?

Does the LT4 MAP have the same size nipple and O-ring as the LS9? I assume it does.

So, do I not install the SCIAP harness and sensor then?

Does doing it this way help when transitioning into boost?

Finally, this seems way too easy LOL. I feel like there will be other things the ECU will be looking for after flipping the switch to supercharger equipped.

[GHuggins]

Thanks for the reply. Is this the schematic you are referring to?

lt4 schematic.jpg

The vehicle in question is my 18 SS with 2650 Maggie. So, my blower kit came with a harness that breaks out the IAT, originally in the MAF. So, correct me if I'm wrong but from what I'm gathering, you are suggesting I put that IAT back in the MAF. Then remove my LS9 map, install the LT4 map, change the map connector to LT4 4 pin, and run the IAT wire to the ECU pin X1 13. Did I interpret that correctly?

Does the LT4 MAP have the same size nipple and O-ring as the LS9? I assume it does.

So, do I not install the SCIAP harness and sensor then?

Does doing it this way help when transitioning into boost?

Finally, this seems way too easy LOL. I feel like there will be other things the ECU will be looking for after flipping the switch to supercharger equipped.

I'm told the supercharger equipped activates the ecm to look for the third temperature sensor and doesn't really do anything else.

You still need the sciap

Yes to wiring and to the lt4 map

Yes to setting pressure switches and corresponding dtc's correctly for operation - even though this wasn't mentioned

Yes to sciap smoothing factor and yes to baro/map error changes - even though this wasn't "all" mentioned

You're still going to have to dial things in for the boost transition. Don't think for a second you can just do all of this and have no problems. I'm actually experimenting with a pedal progression table at the moment which so far seems to be a must for boost addition and does not work anything like I thought it would.

Yes to VVE and torque model tuning even though this wasn't mentioned Still sounding way too easy?

All of this applies to cars only. Won't work on trucks. Cars are a whole lot easier to add boost to. If you were doing a smaller blower you wouldn't need to do a third of this and everything would work good with some tweaking. The bigger the blower the more important things become.

EDIT - Almost forgot - since you're doing a car you're going to need access to the linear and offset tables for the sciap too as these are 0ed from factory on the cars - go figure right - everything else is easier but this

[GPGTP]

Thanks for the reply.

After sifting through several threads on the subject (SCIAP), I feel less confident than when I initially started reading. It seems there is a lot of back and forth on what exactly all needs to be done to make it work correctly?. However, wiring seems fairly straightforward.

LOL, unfortunately I know the effects all too well. I wish we could just apply a patch or do an OS enhancement that would emulate the LT4 OS. Obviously there would be wiring changes needed but I'm fine with that.

While I love my 2650, part of me wishes I went with a centrifugal for this exact reason. I'm hoping with the addition of the SCIAP sensor, my car will transition into boost a little smoother, not that its bad by any means but I would like it to drive like a stock LT4.

In my less that qualified opinion the issue is the NA OS does not factor anything above 1 ATM into its calculation when deciding where to put the throttle blade. The difference between 50% tps and WOT is very small on an NA vehicle, especially at lower engine speeds, but very large on a boosted engine. This is why with a mostly unmodified tune, you see large jumps in tps with relatively small accel inputs. Not to mention the problem is further exasperated when VVT, DOD and TCC are still enabled. I've been considering getting a smooth boost to help combat this issue since it's tps based instead of vacuum but I'm still on the fence. In any event, I appreciate your input, thanks for helping.

I'm told the supercharger equipped activates the ecm to look for the third temperature sensor and doesn't really do anything else.

You still need the sciap

Yes to wiring and to the lt4 map

Yes to setting pressure switches and corresponding dtc's correctly for operation - even though this wasn't mentioned

Yes to sciap smoothing factor and yes to baro/map error changes - even though this wasn't "all" mentioned

You're still going to have to dial things in for the boost transition. Don't think for a second you can just do all of this and have no problems. I'm actually experimenting with a pedal progression table at the moment which so far seems to be a must for boost addition and does not work anything like I thought it would.

Yes to VVE and torque model tuning even though this wasn't mentioned Still sounding way too easy?

All of this applies to cars only. Won't work on trucks. Cars are a whole lot easier to add boost to. If you were doing a smaller blower you wouldn't need to do a third of this and everything would work good with some tweaking. The bigger the blower the more important things become.

EDIT - Almost forgot - since you're doing a car you're going to need access to the linear and offset tables for the sciap too as these are 0ed from factory on the cars - go figure right - everything else is easier but this

[GPGTP]

Support will add them correct? If not then I will definitely need someone to add them for me. I have no issue paying if that's the case and if there are any takers

EDIT - Almost forgot - since you're doing a car you're going to need access to the linear and offset tables for the sciap too as these are 0ed from factory on the cars - go figure right - everything else is easier but this

[GHuggins]

HPT will add the linear and offset tables, but to my knowledge they won't add the sciap smoothing factor or the pedal progression tables unless you show them where they are located yourself.

Yes, I've had my coding expert going through the lt4 and NA calibrations for a while now looking for anything pressure ratio related. I'm afraid it's in something more hard coded and inaccessible. My thought is the sciap readings have to tie into other tables related to this. Otherwise why does the DD in a lt4 vehicle only act as a limiter whereas in everything else NA it has to be dang near perfect for boost. I'm unfamiliar with the other item you're talking about. Going to have to do some looking into that myself. I know everything helps, but I'm still working on how to dial each in to work best with one another such as the pedal progression table - I really thought it would be airflow tied, but instead it's just like the rate limit tables using torque only not how you think it would. Stock has negative values for idle (wondering if this isn't what's controlling timing at idle since 0ing it out will command higher idle timing) and you have to have positive values to rev in neutral otherwise it won't at all - another issue certain platforms have, but driving doesn't matter - the more negative here the better it controls the blade, which makes no sense at all to me.

This is the pedal progression I'm trying out right now. Again I do not fully understand how this works with the OS - this is just what I've partially discovered so far. More negative seems to open a "buffer window" up in the DD table allowing you to run negative DD errors and the throttle still open like pedal commands thus shifting more control to the pedal input. I'm probably completely wrong about that, just what I'm seeing. EDIT - updated pic to show corrected table with some description.

I know you can just install the sciap, change the one setting and it might actually behave better, but this from the more knowledgeable people seems to just put it into some sort of partial REP state, which seems to give the tuner the thought of "more control" or this is the end all solution. The first complaint from the customer however will be - "it just doesn't seem as perky as it was stock". I've noticed this myself and when you set it up more in line with how it's actually supposed to be the sciap only seems to do a little to help, but you get the "perky" throttle feel back. Still 100% necessary, but I really believe there are other correlating tables tied to the sciap somewhere else. I mean if you just think about it, there would have to be right? Otherwise what do the inputs from the sciap correlate to or how does the computer use that input? Kind of like MAF scaling or anything else and different sized blowers and different sized tb's should inevitably change this - right? I know Fords have 4 tables specifically for this relation... I would think GM would have something? Perhaps I'm just overthinking things....

[GHuggins]

Just changing from the factory truck idle -23 value to a value of 0 changed idle timing from 5ish degrees to 13ish degrees and idle torque from -6lbft to a steadyish 17lbft. It also brought torque requested by axle back to near stock values and stock control (not jumping around anymore). Found that very interesting. This may be the table we've all been looking for on certain chassis. Also means I'm going to most likely have to start modifying this on some cam tunes.... Hmmmm....

[GHuggins]

So I wound up changing that throttle progression or pedal progression or whatever table a lot. Looks like a dumptruck bed now lol BUT throttle is SUPER responsive with the throttle rate limit adjustments and follows commanded or pedal fairly closely. It is still overshooting at 60% pedal just a touch, but I'm certain some DD cleanup can hopefully take care of this. I left idle 0ed out and am currently checking a cam tune that I 0ed it out on to see how much better idle is on it.

I'm pretty sure this truck has the newer bigger whipple on it instead of the older 2.9l. All I know is the owner is fairly happy with it now as it's performing more like a factory blown car instead of the slug setup it was.

I just can't get over how different this table is platform to platform. This truck for instance I maxed it out at 1280 for the throttle opening at 100 pedal at idle and it's using axle torque for reference. Some of the ZL1's have values as high as 8200 from factory using engine torque. Really wish I knew exactly what these torque numbers were being used to offset, but they definitely seem to be used for all engine operations...

There still has to be a pressure ratio table somewhere as that would take care of all of these problems. Just not sure where.

[will_974]

Hey,

As requested.
I am taking orders for adjusting SCIAP parameters.
You can PM me directly, But i would prefer you use the website in my bio.
I am only one person, so please play nice.

https://minigeist.net/blog/

[GHuggins]

Thanks for the reply.

After sifting through several threads on the subject (SCIAP), I feel less confident than when I initially started reading. It seems there is a lot of back and forth on what exactly all needs to be done to make it work correctly?. However, wiring seems fairly straightforward.

LOL, unfortunately I know the effects all too well. I wish we could just apply a patch or do an OS enhancement that would emulate the LT4 OS. Obviously there would be wiring changes needed but I'm fine with that.

While I love my 2650, part of me wishes I went with a centrifugal for this exact reason. I'm hoping with the addition of the SCIAP sensor, my car will transition into boost a little smoother, not that its bad by any means but I would like it to drive like a stock LT4.

In my less that qualified opinion the issue is the NA OS does not factor anything above 1 ATM into its calculation when deciding where to put the throttle blade. The difference between 50% tps and WOT is very small on an NA vehicle, especially at lower engine speeds, but very large on a boosted engine. This is why with a mostly unmodified tune, you see large jumps in tps with relatively small accel inputs. Not to mention the problem is further exasperated when VVT, DOD and TCC are still enabled. I've been considering getting a smooth boost to help combat this issue since it's tps based instead of vacuum but I'm still on the fence. In any event, I appreciate your input, thanks for helping.

I might eventually do a full write up on it, but for now Will_974 appears to have found the key tables and full throttle control is possible with the stock calibration with a PD blower or any type of boost in general. Requires 2 key tables then some others depending on how OE you want it. I also confirmed that variable cam timing no longer will throw the throttle out of whack with these tables adjusted

[GPGTP]

I might eventually do a full write up on it, but for now Will_974 appears to have found the key
tables and full throttle control is possible with the stock calibration with a PD blower or any type of boost in general. Requires 2 key tables then some others depending on how OE you want it. I also confirmed that variable cam timing no longer will throw the throttle out of whack with these tables adjusted

Very interesting stuff. I appreciate you brainstorming on here. Yea a friend wanted me to tune his whipple Silverado and I finally gave up after a very long time, I could not get the throttle to open smoothly when transitioning into boost. Maybe the pedal progression table would have helped. As soon as I get a second to myself I?m going to start by installing the SCIAP map sensor and harness and note the effects.

[GHuggins]

Very interesting stuff. I appreciate you brainstorming on here. Yea a friend wanted me to tune his whipple Silverado and I finally gave up after a very long time, I could not get the throttle to open smoothly when transitioning into boost. Maybe the pedal progression table would have helped. As soon as I get a second to myself I?m going to start by installing the SCIAP map sensor and harness and note the effects.

Just keep in mind if not setup correctly the sciap on it's own will put the ecm into some sort of partial failsafe, so it will seem like it's fixed everything but throttle response will suffer.

I'm still planning on doing a write up with full explanation into how the tables work and how they need to be adjusted, but yes the trucks in particular will GREATLY benefit from this just because of the rate table that's in trucks. You see trucks are setup to tow and climb hills with all that extra weight without having to give extra throttle - it opens on it's own. It does that because of the rate table, which is why it's damn near impossible to tune a blown truck running a large pd blower and with a lot of boost kick in at that.

To fix the trucks issues you need the throttle rate and pedal progression tables on top of the usual's.

Lots of others in there too that Will has found and Verlon has helped to point out as well that's still being verified. I'll be doing the write up when I can get to it...

[GPGTP]

I might eventually do a full write up on it, but for now Will_974 appears to have found the key tables and full throttle control is possible with the stock calibration with a PD blower or any type of boost in general. Requires 2 key tables then some others depending on how OE you want it. I also confirmed that variable cam timing no longer will throw the throttle out of whack with these tables adjusted

Be very interested to read your write up when you do finally get to it. I?ve always said there has to be a throttle rate table that?s not mapped. After all it has to equate a throttle opening to an airflow number otherwise how would it calculate where to target? I plan on purchasing the needed parameters from will I?m just not certain what I need to get from him, I sent him a PM, hopefully he responds. I know I need the linear and offset for the SCIAP and the slope tables. I already have the pedal progression but not the throttle rate so I?ll need that too. I also see a spot to check enable IAT2. I thought switching to supercharger enable turned that on, so idk if I need that. So, does he map the tables or does he edit them as well? I have user defined parameters for my unit and tuner pro but I?m not certain how to use it exactly for this application. I?ll mess with it when I get a minute.

[will_974]

I responded to your PM.

The camaros' dont benefit much from the the Throttle rate table,
Since you already have the Pedal Progression table,
You can swap over the LT4 pedal progression table without my intervention.

I suggest a base Package of this product.
(with the XDF switch if you would like)
https://minigeist.net/blog/?product=...-configuration

The Enable IAT2 switch is not necessary until you are trying to set 'supercharger fitted'
It is a different switch that i have played with, It does a bunch of code switching but i cant figure out the delta.

I will Map the tables and adjust them as the Base product.
If you toggle the XDF file switch I'll send you the XDF file with the paramenters from the product.
The user defined parameters will open the XDF file, and you will be able to see the tables that are defined inside it.