GruvenParts.com Corrado SLC Supercharger Build Thread

[angelod307]

My bad a c2 tune. Same question though? With the c2 , is it cutting off, i guess not as I have not read any such issue in your build.

[GruvenParts.com]

Im using a C2 chip, the GIAC ran too lean at higher RPM.

C2 chip is doing fine, no issues up to 9 psi.

[s.l.c.]

Anyone else want a 2.4" pulley, or oversized crank ?

I would be interested after the 2.4 been tested.

[angelod307]

Im using a C2 chip, the GIAC ran too lean at higher RPM.

C2 chip is doing fine, no issues up to 9 psi.

Wonder why I have issue 's then with the c2.

[DeckManDubs]

Wonder why I have issue 's then with the c2.

The C2 and UM chip are not long term solutions for Supercharged application. Washed down cylinder walls and detonation issues, bucking, stalling all get worse the longer the C2 chip is on the car. Standalone is the only solution to running more boost than VF originally intended with the Garret tune.

[ein]

The C2 and UM chip are not long term solutions for Supercharged application. Washed down cylinder walls and detonation issues, bucking, stalling all get worse the longer the C2 chip is on the car. Standalone is the only solution to running more boost than VF originally intended with the Garret tune.

This PSA brought to you by experience.....

[thevisualedge]

I also have no idea how people attach the radiator neck to their radiator. The stock plastic one wont fit and our metal neck doesnt either.

Be glad you sent it back. I just went through hell and back getting my Godspeed hooked up to my Corrado. I had to do the following:

1) Bore out the holes where the tabs sit so I could gently wedge the radiator into place

2) Dremel the round opening in the radiator so I could get my snazzy GruvenParts rad neck in it ... which didn't fit until I went medieval on it with a rubber mallet

3) Drill & tap a new screw hole to bolt down the elbow because the two supplied holes don't line up with the elbow;

4) Grind down the tab near the driver's side/battery area that butts up against the radiator and keeps it from getting properly seated

5) Use muscle to get the driver's side A/C line attached back to the condenser ... why? Because Godspeed put the fan switch too low on the radiator core, and it prevents the A/C line from coming up high enough to make a smooth, easy attachment.

6) Lastly, the "L" shaped metal tabs that secure the radiator to the rad support don't come anywhere near fitting correctly. The slots in the radiator aren't nearly deep enough for the tabs to slide in, and even if they did, the holes for the appropriate bolts are way off.

After all that frustration, my Godspeed is in the car securely and does its job pretty well ... but the fitment headaches aren't worth it one bit. I haven't tried PWR, but it can't possibly fit worse than this thing!

[GruvenParts.com]

Agree, I was pretty pissed with them. I offered to help redesign the radiator and chung seemed interested in getting it right at 1st. I never heard back and just decided to move on and send the ill fitting metal radiator back. then he charged me $40 on return shipping for it..

What I told him we need is AN EXACT REPLICA of the OEM radiator, just metal not plastic. It doesnt need to be 1" bigger and it will not fit if it is. The stock one just barely fits.

Anyways, glad you finally got it in place, show us some install pics.


FYI I have the 2.4" serp pulley CAD drawing done and shop is programming CNC. We'll run 5 or so, if you want 1 shoot me an email and I will hold for you. We are also making several more tensioner turnbuckles.

FYI 2 - I had no issues getting 9 psi out of my C2 chip with the larger injectors VF provided in their stage 2 kit. I did have ridiculous bucking issues, but I simply removed the idle stabilizer valve and manually set idle for 1k or so. It works fine and no bucking. Dont know how much more than 9psi you can possibly get, this was running pretty close to max impeller speed with a custom cog set up. I suppose a intercooler would help, and maybe more aggressive impeller pitch if you are so willing. 9 was pretty damn quick

[GruvenParts.com]

Can someone comment as to why my V9 is dripping so much oil down the intake tube to filter?

This is freshly rebuilt. Todd (@superchargerrebuild.com) just said that is completely normal for V9's.

Hell this is alot of oil ! Maybe I overfilled on last oil change...

Update : still running the 6 psi serp pulley. Not slipping but only 6 psi. Kinda boring ... Still waiting for a machine to open up so I can get a 9 psi serp pulley to test out with out turn buckle tensioner. Stay tuned ...

[DeckManDubs]

Can someone comment as to why my V9 is dripping so much oil down the intake tube to filter?

This is freshly rebuilt. Todd (@superchargerrebuild.com) just said that is completely normal for V9's.

Hell this is alot of oil ! Maybe I overfilled on last oil change...

Update : still running the 6 psi serp pulley. Not slipping but only 6 psi. Kinda boring ... Still waiting for a machine to open up so I can get a 9 psi serp pulley to test out with out turn buckle tensioner. Stay tuned ...

Because the V9 has the positive pressure case. It is to evacuate oil out of the charger via the drain line...yet it will also cause the oil to make it out any other way possible.

[GruvenParts.com]

I also wonder if this could be made worse by the oil return tapped into the pan.

It leaked very little oil before last oil change, now after the oil change its really pushing lots of oil down the intake filter tube. This sudden change may be caused by the oil level in the pan is sitting higher than the return line. Whereas prior to oil change it was probably sitting a bit lower in the pan.

Hell maybe I should tap the block to get the return up higher...although I would hate to do that

[DeckManDubs]

I also wonder if this could be made worse by the oil return tapped into the pan.

It leaked very little oil before last oil change, now after the oil change its really pushing lots of oil down the intake filter tube. This sudden change may be caused by the oil level in the pan is sitting higher than the return line. Whereas prior to oil change it was probably sitting a bit lower in the pan.

Hell maybe I should tap the block to get the return up higher...although I would hate to do that

You can also increase the size of the return line to help with the flow. Or you can pull the high pressure line off the charger and run it like every other charger.

[CalVW]

I tapped the block after having massive amount of oil going down the intake also. Just be weary that tapping the block reduced the amount of oil in the intake but did not stop the problem. Also, if you only fill the oil level to half way up the hashes on the dipstick, there will be less oil in the intake. I'm running a Setrap oil cooler with my setup so there is plenty of oil in the system.

[CalVW]

You can also increase the size of the return line to help with the flow. Or you can pull the high pressure line off the charger and run it like every other charger.

I like the idea of increasing the size of the return line. Did you try that? If not, has anyone tried that with success?

[GruvenParts.com]

I remember speaking with the previous owner of my V9 kit. He did tap the block, and he also still had quite a bit of oil going down into the intake tube. So I dont think tapping block is right solution, at least for that issue anyways.

I will look into using larger return hose, but its limited by the return line fittings on the charger and oil pan so using a larger hose in between probably wont do much to help. Also not sure where else to draw the oil from other than the filter head. Im sure its seeing 80 psi oil pressure coming off that location, but where else in system is a better place to feed from? Maybe a pressure regulator can be installed.

This problem is mitigating as the oil level comes down, I guess I just need to remember to fill to 5 qts not 6.3 on next oil change. Im also running the setrab 9 row oil cooler up front.

Thx for all suggestions

[CorradoMagic]

the return line should be a -10an, anything smaller will likely not flow enough

[GruvenParts.com]

Oil level now down in the pan a bit more, its definitely leaking much less oil. I guess its OK to put return line in pan, just dont fill oil level too high or it wont drain correctly and oil will come out of the intake tube. Otherwise things are still running fine, still waiting for CNC machine to open to make the smaller rib pulley for charger (8-9 psi). I will have to see if that slips with our tensioner turnbuckle.

Someone else suggested building larger crank pulley, we could do that but would over drive the other components. Thoughts ?

[DeckManDubs]

Oil level now down in the pan a bit more, its definitely leaking much less oil. I guess its OK to put return line in pan, just dont fill oil level too high or it wont drain correctly and oil will come out of the intake tube. Otherwise things are still running fine, still waiting for CNC machine to open to make the smaller rib pulley for charger (8-9 psi). I will have to see if that slips with our tensioner turnbuckle.

Someone else suggested building larger crank pulley, we could do that but would over drive the other components. Thoughts ?

Running 10-15% overdrive will be fine on the stock system. Only thing that you might not want to overdrive would be the waterpump due to flow stall if the fins spin too fast.

[angelod307]

wow, been there for a while now with 9 psi. the stand alone bull**** is for the birds. i started down this path with a standalone and two or so years later, i still do not have a great tune. as for the pulley, well, the 9 psi is a blast, but i think the amount of tension i put on it not to slip will wear something out sooner than later. i got another idler pulley from vf for the stage 3 kit to help with slip, does ok most of the time. my first belt lasted less than 20k before it was toast. so, if i had a machine shop at my disposal, i would have a oversized crank pulley with a regular 2.7 or as big as i could get away with on the charger pulley with undersized pulleys for the rest of the stuff. fueling is and has been my issue . who has a tune for a lugtronics with a stage two kit and injectors, with a stage almost 3 charger pulley ?

[BlackSwan]

Is the turnbuckle tensioner, oversized crank pulley or 2.4" sc pulley available??

[GruvenParts.com]

I havent had anyone wanting them yet but we can do a run. Let me know if you would rather have 2.4" charger pulley, or larger crank. We have CAD drawings and programs ready for all of it.

[CuRide]

I'm over it! On the path to charger-less

[GruvenParts.com]

I got 3 kids, man, ease up.

I have been tweaking my sc set up for quite a while, but in my opinion it still isnt reliable enough to track it on Road ATL. Ive been able to get 10 psi off my cog set up, with air conditioning. That is an accomplishment in itself.

Still working on it though.

Some other things Ive figured out :

1. The VF Engr diverter valve opens at 6 psi. I put a shim under the spring, now it opens at 10 psi. Honestly dont know how I was getting 10 before with the valve opening at 6. It would of been pushing more like 12 or 13 had I known that.

2. VF supplies a poorly designed tube from charger to intake tbody. The charger side of tube is 3" while tbody is more like 3.25". Once you reach a certain level of boost, this sort of mismatch doesnt work. The short silicone 3.5" ID tubing supplied with their kit will pop off the intake tube. Thankfully, Summit racing sells a 3 to 3.25 silicone tube which should fix all this.

3. I moved air intake back over to pass side. Since I deleted the Idle Stab valve, the bucking is gone. But its now a bit touchy, with MAF so close to SC. There is seemingly no way to intelligently locate intake on the pass side, unless you feel like sucking up a pond everytime it rains. I cant have that, so I think I will re-relocate MAF back to drivers side. Issue there is the 3" tubing sticks out from bottom of air dam and you will scrape it constantly. Need to find solution there, perhaps rectangular tubing and we will fab up some brackets.

I tell you what, for a "turn key out of the box" solution, VF really screwed the pooch. You would be better off just buying a V9 or similar from Vortec and rigging this up yourself. It seems everything custom they supplied with this kit works like 10 lbs of dogsh!t.

If 10 psi in a VR wasnt so damn addictive I would of kicked this idea a long time ago. But it was kinda fun to absolutely DUST a BMW X6 twin turbo V8 the other day. 1 of those deals where he was turning left, I was turning right, we kinda met in the middle and it was one of those unspoken rules where you have to see who earns the single merge lane ahead. Wow the engine in those things sounds like a thing of beauty, but I bet he wasnt expecting the result .. In all fairness, I was in the sweet spot of 2nd gear and I sorta waited on em to see if he was gonna try. Man was I happy when he did

[corrado-correr]

In all fairness, I was in the sweet spot of 2nd gear and I sorta waited on em to see if he was gonna try. Man was I happy when he did

this is really sweet, i know exactly what youre talking about.

[Noobercorn]

The C2 and UM chip are not long term solutions for Supercharged application. Washed down cylinder walls and detonation issues, bucking, stalling all get worse the longer the C2 chip is on the car. Standalone is the only solution to running more boost than VF originally intended with the Garret tune.

You and I both know this is FALSE information.

Hell, the OBD2 dizzy software was written off MY CAR (3 months up in CT, SWINK was kind enough to bring her back to a SY/TY meet)

FYI: SY/Ty is GMC Syclone and Typhoon for those that don't know

[DeckManDubs]

You and I both know this is FALSE information.

Hell, the OBD2 dizzy software was written off MY CAR (3 months up in CT, SWINK was kind enough to bring her back to a SY/TY meet)

FYI: SY/Ty is GMC Syclone and Typhoon for those that don't know

Mike, you need to lay off the dope. Lot of people have issues with the software even running turbo. But lets not get into this on Gruvens thread. I have plenty of 12v paper weights from Jeff's tunes. Simply put, they suck.

[ThaCorradoKid]

most turbo tunes will suck for s/c applications. (once spooled) turbo's hit full boost quick and hold it or even taper off as rpm's rise. that is the complete opposite of how a (centrifugal) s/c behaves: making almost no boost until midway up the rpm range and then rising in a linear fashion until peak boost is made at or in the redline.

that's why turbo tunes dump way too much fuel early. there is no way the same fuel map will work properly for such different applications.

specialized s/c tunes work much better, but are not written for high boost/air volume. until someone makes a chip that is, we will continue to have this problem and standalone will be the only route for 250+ whp s/c'd VR's.

all in my most humble opinion, and I am actually trying to prove myself wrong.

[adg44]

3. I moved air intake back over to pass side. Since I deleted the Idle Stab valve, the bucking is gone. But its now a bit touchy, with MAF so close to SC. There is seemingly no way to intelligently locate intake on the pass side, unless you feel like sucking up a pond everytime it rains. I cant have that, so I think I will re-relocate MAF back to drivers side. Issue there is the 3" tubing sticks out from bottom of air dam and you will scrape it constantly. Need to find solution there, perhaps rectangular tubing and we will fab up some brackets.

Here is what I did - no bucking, and it rarely ever stalls unless I've been romping on it and then suddenly put in the clutch and it has a hard time catching the revs at idle:



This is all on the passenger side as well. There is maybe 15" of tubing to move the MAF/filter from the supercharger inlet to the lower front part of the bumper.

[CalVW]

That works. The pic is showing that darn oil drip from the V-9. I have the same problem, as does Gruven. So I guess it is normal just like what the charger rebuilder said?

I'm still running the stock sparkplugs on Stage 2, 8lbs, in mild-weathered California. What plugs are you guys using?

[adg44]

That works. The pic is showing that darn oil drip from the V-9. I have the same problem, as does Gruven. So I guess it is normal just like what the charger rebuilder said?

Where is your oil drip from your V-9?

That drip was from the oil fitting on the top of the blower. I fixed it by using some thread sealant, as the oil was seeping out from the threads. It hasn't leaked (at least from that location) for the past three and a half years. Is yours leaking from a different spot?

I'm still running the stock sparkplugs on Stage 2, 8lbs, in mild-weathered California. What plugs are you guys using?

I am using one heat range cooler NGKs. I'm pretty sure they are the BKR6E. Some people are running the 7E, but I didn't feel the need to go two ranges cooler. I also am using copper plugs, not the platinum ones. I'd suggest you go at least one range cooler with your setup.

[GruvenParts.com]

Im using stock plugs.

Anthony thanks for that pic, I remember if from the 1st page. This is essentially what I have done for the time being. You cant drive that in the rain though, and it rains down here quite a bit. The MAF gets wet and it wont run very well.

Since I removed the Idle Stab Valve, I figured I could just put the MAF right up against the charger inlet tube, then run a Spectre U down then up, to a short air filter. It bolted up perfectly, the tubing was a good 1" above the air dam at lowest point, and the air filter was nestled just under the headlight, perfect and dry. Except it made 4 psi like this, even at redline. So I took that out and did like in Anthony's pic, back to 8 psi. You would think the charger is purely mechanical, as long as you arent dumping boost somewhere, if it revs to 6,000 RPM, it has to make the right boost, regardless of where MAF is put. Not true. So anyways, Ive got it set up like yours now Anthony, and I have to watch the weather channel alot.

Regarding oil drips, yes I have always gotten oil dripping down the intake tube all the way back to filter. It was significant lately, I figured I over filled oil level a little on last oil change. Well, it turns out when I replaced the oil feed check check valve, I put it in backwards. So I was pushing 80 psi oil into the air intake (through a tiny pin hole in the check valve, so it wasnt too bad). The oil was collecting in the diverter valve, then dumping back down into intake tube. So, I think that was majority of my issue. I reversed the check valve installation and now am only getting a little oil down intake tube. As was mentioned already, this is just how the V9 operates.

So its all back together again, and now I just busted the expansion tank where tiny hose plugs into the top. No good way to fix, so I have 1 on special order from dealer, should be here Friday and we'll get it running again.

Still deciding on larger crank vs 2.4" diameter charger pulley. Email me if you want 1, I will have the shop buy a stick and make a run. I almost just want to do the larger crank pulley because its such a PIA to remove charger to change out pulley ...

[adg44]

Anthony thanks for that pic, I remember if from the 1st page. This is essentially what I have done for the time being. You cant drive that in the rain though, and it rains down here quite a bit. The MAF gets wet and it wont run very well.

I've been in the rain a few times with the Corrado and never noticed a problem. Granted I haven't taken it out in any downpours, but it is somewhat protected by the front bumper as well as the lower splash shield.

Regarding oil drips, yes I have always gotten oil dripping down the intake tube all the way back to filter. It was significant lately, I figured I over filled oil level a little on last oil change. Well, it turns out when I replaced the oil feed check check valve, I put it in backwards. So I was pushing 80 psi oil into the air intake (through a tiny pin hole in the check valve, so it wasnt too bad). The oil was collecting in the diverter valve, then dumping back down into intake tube. So, I think that was majority of my issue. I reversed the check valve installation and now am only getting a little oil down intake tube. As was mentioned already, this is just how the V9 operates.

Interesting. Do you have a photo of the oil drip? It's dripping on the inside of the intake tube or the outside?

And why are you still using the stock plugs?

[GruvenParts.com]

I have run mine a few times in moderate rain. It soaks the air filter and water starts dripping onto the MAF, which causes hesitation and bucking. Its not fun, and the filter takes a few days to dry out if you really soak it. I would be careful, you definitely dont want to get water all the way to engine and hydro lock it.

Oil on my V9 seems to emanate from the charger inlet fan seal itself. When I spoke with Todd at S/C rebuilds.com he said that is normal for V9, it just doesnt do a great job sealing at that inlet fan seal. That is kind of disappointing, but it sounds like yours in not leaking at all or as much? So maybe my V9 is just somehow defective at that seal.

Regarding plugs ... I bought the whole kit from someone else, I didnt know the plugs were required to be changed out. The PO was using original plugs, too. The OEM style plugs/wires are running fine in my car, this is a OBD1 dizzy car.

Anthony do you notice minor bucking under vacuum, like if you run it up to 5-6k rpm then let it coast back down to 3-4k and hold it there? Does it kinda feel like you are on a knife edge with the throttle? Mine is doing that a bit with your air filter/maf set up. It did not do that all all with filter on pass side of car.

I got the new coolant expansion tank in and the silicone adapter from tbody to charger tube will be here tomorrow. I will install that, hopefully will stop blowing off the silicone tubing which connects the 3.25" tbody to the 3.0" charger tube.

[adg44]

I have run mine a few times in moderate rain. It soaks the air filter and water starts dripping onto the MAF, which causes hesitation and bucking. Its not fun, and the filter takes a few days to dry out if you really soak it. I would be careful, you definitely dont want to get water all the way to engine and hydro lock it.

I used to run my AEM cold air intake on my Mk4 VR6 in the rain, and as long as it wasn't submerged there was no problem. But I agree, water on the maf and filter should be avoided if possible.

Oil on my V9 seems to emanate from the charger inlet fan seal itself. When I spoke with Todd at S/C rebuilds.com he said that is normal for V9, it just doesnt do a great job sealing at that inlet fan seal. That is kind of disappointing, but it sounds like yours in not leaking at all or as much? So maybe my V9 is just somehow defective at that seal.

I'll need to check mine. I have noticed some oil on the splash shield by the air filter, but I also have an oil leak coming from the oil pan gasket as well as the oil filter housing, so who the hell knows where it's actually coming from.

Regarding plugs ... I bought the whole kit from someone else, I didnt know the plugs were required to be changed out. The PO was using original plugs, too. The OEM style plugs/wires are running fine in my car, this is a OBD1 dizzy car.

No need to use the OEM platinum plugs. Go for the copper versions 1 or 2 ranges cooler and you'll like it. Mine had a noticeable difference once I did that.

Anthony do you notice minor bucking under vacuum, like if you run it up to 5-6k rpm then let it coast back down to 3-4k and hold it there? Does it kinda feel like you are on a knife edge with the throttle? Mine is doing that a bit with your air filter/maf set up. It did not do that all all with filter on pass side of car.

I really haven't noticed any bucking at all with my supercharger once I moved the MAF further away from the blower. I don't even have any extra straightener behind the MAF.

I should likely drive the car sometime this week - I'll take it up to 5k then let it coast back to 3-4k and hold it there and let you know. I assume you might be having this because you're flowing more air than I am (stock pulley/6psi).

- Anthony

[CorradoMagic]

colder plugs is a must for anything beyond 6#. the cheap NGK BKR6E is 1 stage colder & good till 11#~.
Regapping to a closer .26-.28 helps as well.

As far as too much oil pressure, try an oil restricter in the -4an feed line.
again, the return line should be -10an for best flow back to the pan.

As someone who has washed their motor on a variety os OBD1 coilpack C2 chips, I can confirm they are not ideal for SC setups/fueling. The later revised OBD2 tunes are better, but could certainly use improvement.