LT1-LT4 Modifications - Ls1 lid conversion with fitment issue: Wich rubber coupling do i use ?

Well im doing my Lid conversion(slp lid,complete lower air box and FTRA).I got a harwood ws6 ram air hood so i dont need to cut anything and i dont want to,so no cutting on the rad or the hood or the frame, etc,etc....Im having a trouble to make the connection between the MAF and the TB.Like a lot of people told me here ,i ve bought a Fernco 3inch to 3 inch coupler but it doesnt fit perfectly.So i would need help to finish this once and for all :devil:

I dont have my camera to take pics but i ve found the exact problem that i have on the board so here it is:

http://www.ls1tech.com/forums/attachments/lt1-lt4-modifications/220082d1268070327-who-says-cowl-hood-cant-functional-fi-car-james-pics-002.jpg

So you can clearly see that the maf is angle down while the tb is level :bang:

What would be your solution(dont wanna cut the lid please)?

I was thinking abour a 45degree 3inch coupling but not sure about that,i want the most smooth way possible.Link is only there for example:
http://cgi.ebay.co.uk/BLACK-76mm-3-Silicone-Hose-45-degree-Elbow-Bend_W0QQitemZ290331161421QQcmdZViewItemQQptZUK_Ca rsParts_Vehicles_CarParts_SM?hash=item439915f34d

Thanks

I have the same hood and problem. I used a straight Fernco 3" to 3" and a peice of the moroso CAI to help span the distance. I think I am going to pull the MAF out of the lid and use a small peice of silicon to space the maf out and then use the fernco from the maf to the tb

http://i898.photobucket.com/albums/ac182/ak_deckbar/DSC_0011.jpg
http://i898.photobucket.com/albums/ac182/ak_deckbar/DSC_0012.jpg

The stock Ls1 boot works just fine

I have the same hood and problem. I used a straight Fernco 3" to 3" and a peice of the moroso CAI to help span the distance. I think I am going to pull the MAF out of the lid and use a small peice of silicon to space the maf out and then use the fernco from the maf to the tb


Didnt think about that ;)
I will keep this solution has a backup if i cant make it with one boot only.

The stock Ls1 boot works just fine
Your talking about the accordion one...i was thinking about a smooth one so the flow would be optimal.

Try this site:

http://www.siliconeintakes.com/product_info.php?cPath=4&products_id=20&osCsid=9b8b13d4dc17100b931d3e8043dfc0e2

There is absolutely no true gain in the different boots but its your choice. No gain or loss at the track on my car.

I have a smooth one..4" in diameter..goes from my TB to the MAF, I needed the 4" cause I have a 90mm TB and the Z06 MAF.

I don't see why a 3.5" wouldn't fit the oval LT1 TB..maybe it needs to be a 4" to 3.5"..4" on the TB side, and 3.5" on the stock MAF side. I had to use one like that for the MAF to the Lid..
http://www.ls1tech.com/forums/picture.php?albumid=56&pictureid=34253

Not sure about which particular one fits a stock LT1 TB..I'm sure someone knows though.

I'm pretty sure I used a 3" Fernco on my build. It looks like it won't fit at first, but if you boil it, it will stretch out pretty good.

I am using one of these. Although I don't have a MAF anymore.

http://intakehoses.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=I&Category_Code=CACH5

..it will stretch out pretty good.

That's what she said..:naughty:

That's what she said..:naughty:

lol fun fun

I used NO coupler from the lid to the MAF. If you try it the MAF slips inside the lid and fits perfectly. At least it did on mine. It's so tight I dont even need a clamp.

On the MAF to TB end I used a Fernco and didn't boil it. Just manned up and put it on the TB.

I used NO coupler from the lid to the MAF. If you try it the MAF slips inside the lid and fits perfectly. At least it did on mine. It's so tight I dont even need a clamp.

On the MAF to TB end I used a Fernco and didn't boil it. Just manned up and put it on the TB.

exactly what i did!:D

old pic from the beginning of LID swap
http://i104.photobucket.com/albums/m173/rudy_028/96LtX1.jpg

I used NO coupler from the lid to the MAF. If you try it the MAF slips inside the lid and fits perfectly. At least it did on mine. It's so tight I dont even need a clamp.

On the MAF to TB end I used a Fernco and didn't boil it. Just manned up and put it on the TB.

I did the same thing worked great. :D

I know it's more money, but I thought I heard the SLP smooth bellows works perfectly, is that true?

I can get the 3" fernco on the TB no problem. If you call that "manning up" you probaly have a worn out mangina.
The reason my MAF isn't in the lid ANYMORE is to help with distance from the lid to the TB. See, I didn't cut one part of my car up to do this( Thank You Harwood hood ) I trimmed the bottom of the ls radiator support to accomplish this and it all fell into place :chug:

i think most of you guys that didn't have issues with it is because you didn't use the lower ls1 support. It raises the lid alot and changes the angle going to the tb, that's where the trouble starts. I've had the same issues as this cat so I know where he's comin from. I should have the proble solved in the next day or two tho.

^^Yea that angle is a bitch..I have the LS K-member with my Engine, I don't know if the LS Intake/TB sits higher than the LT1..I think it may just by a little bit.

i think most of you guys that didn't have issues with it is because you didn't use the lower ls1 support. It raises the lid alot and changes the angle going to the tb, that's where the trouble starts. I've had the same issues as this cat so I know where he's comin from. I should have the proble solved in the next day or two tho.

You got it :judge:

When you dont use the lower airbox the lid output sit at the same level has the tb.But when you use the complete assembly it make the ouptut ouf the lid higher and give it a damn angle...

You got it :judge:

When you dont use the lower airbox the lid output sit at the same level has the tb.But when you use the complete assembly it make the ouptut ouf the lid higher and give it a damn angle...

Hey G,
I got mine working last nite, I just got another short coupler and slipped over the lid exit and the MAF. All is well, the car screamed up high last nite!!!

For anyone else thinking of doing this, avoid Lowe's American Valve brand plastic coupler - it will warp after a day, put a damper on the air flow and its a little pricier than the Fernco:

American Valve Brand:
http://marc1130.home.comcast.net/~marc1130/airlid/DSCN2040.jpg

American Valve Brand:
http://marc1130.home.comcast.net/~marc1130/airlid/DSCN2042.jpg

Fernco:
http://marc1130.home.comcast.net/~marc1130/airlid/DSCN2093.jpg

Fernco:
http://marc1130.home.comcast.net/~marc1130/airlid/DSCN2096.jpg

Fernco:
http://marc1130.home.comcast.net/~marc1130/airlid/DSCN2098.jpg

This is the one I used. Figured I would get something that is actually made to fit instead of some ugly sewer connector.

http://intakehoses.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=4H35&Category_Code=RHH8

I've noticed on other peoples setups that used the complete lower airbox that the lid sat much higher. Mine lines up very well, but I just used the upper rad support piece. I used a 1/2 fernco from maf to tb, then flexible part of my old rubber intake from lid to maf. I think it looks very clean and factory. Link below.

looks good, in my case i have a 98+ front end with the taller ws6 lower airbox, all of which was unmodified because it fits no problem, mine definitely sits 3" higher.

i used the smooth air bellow that came with the LS1 lid. It worked ok, not entirely happy with how it connects but it works. If it was 1in longer and had a little more of an angle it would be perfect.

I had the same issues with it being at a different height then the throttle body.

is the lid really better than the k&n intake???
I've heard its not

Good thread. I’ve been wondering how I’m going to address this problem when I do my lid swap. My engine already sits lower than normal thanks to my BMR k-member, so I know its going to be a challenge to link up the MAF between the lid and TB… and I won’t be carving up the lid base/rad support b/c it can clear my ram air hood.

A 45 degree silicon pipe or this other one someone posted http://intakehoses.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=4H35&Category_Code=RHH8 looks pretty smart. As for coupler widths, aren’t we all running 3.5” MAF regardless of year? Until now I understood we needed (and as far as I know I’m currently using) a 3.5” to 4” coupler to connect the MAF to TB. Guy’s are using a 3” to 3” to do this??

I used a 1/2 fernco from maf to tb, then flexible part of my old rubber intake from lid to maf. I think it looks very clean and factory. Link below.

I like this piece you are using
http://www.fquick.com/garages/viewgallery.php?action=viewimg&id=311346

is that a 3.5" to 4" fernco reducer?

Good thread. I’ve been wondering how I’m going to address this problem when I do my lid swap. My engine already sits lower than normal thanks to my BMR k-member, so I know its going to be a challenge to link up the MAF between the lid and TB… and I won’t be carving up the lid base/rad support b/c it can clear my ram air hood.

A 45 degree silicon pipe or this other one someone posted http://intakehoses.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=4H35&Category_Code=RHH8 looks pretty smart. As for coupler widths, aren’t we all running 3.5” MAF regardless of year? Until now I understood we needed (and as far as I know I’m currently using) a 3.5” to 4” coupler to connect the MAF to TB. Guy’s are using a 3” to 3” to do this??


Part of the misunderstanding here is due to the fact that the Fernco 3" coupler that sooooooooo .......... many people are using is NOT really 3 inches in inside diameter!:nod:

Please reference my post in this thread: http://www.camaroz28.com/forums/showthread.php?t=645462

to see the actual dimensions of the "3 inch" Fernco.

Part of the misunderstanding here is due to the fact that the Fernco 3" coupler that sooooooooo .......... many people are using is NOT really 3 inches in inside diameter!:nod:

Please reference my post in this thread: http://www.camaroz28.com/forums/showthread.php?t=645462

to see the actual dimensions of the "3 inch" Fernco.

INteresting... so what would the inside diameter of a 4" to 3" fernco coupler be on the 4" side? This is the closest/quickest thing I've found and something I can buy locally:
http://www.homedepot.ca/product/4-in-to-3-in-cast-iron-plastic-copper-steel-or-lead-pipe-flexible-coupling/977091
As long as the 3" side will fit over the MAF that's great. And if the 4" side is actually larger then it will fit over the TB no problem but hopefully it won't be too wide (although the clamps would tighten it either way).

I still like that reducer with the bulge in the middle ( http://intakehoses.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=4H35&Category_Code=RHH8 ). This one looks ideal for those of us who need to bend the coupler to correct the downward angle from the lid.

I have no idea why people are using couplers from the MAF-Lid considering lids were designed to have the maf slid into them. :confused:

I like this piece you are using
http://www.fquick.com/garages/viewgallery.php?action=viewimg&id=311346

is that a 3.5" to 4" fernco reducer?

No, it's just 1/2 of a 3" fernco coupler. If you heat it up for a few minutes in a pot of hot water it gets very soft and flexible, then you can quickly put it on the tb. It will mold to the oval shape of the tb very easily. Them connect the maf to it, that fits easily on it. From the maf to tb is part of my old intake bellow, it makes a nice connector when you cut it off the rubber elbow and trim it a bit.

INteresting... so what would the inside diameter of a 4" to 3" fernco coupler be on the 4" side? This is the closest/quickest thing I've found and something I can buy locally:
http://www.homedepot.ca/product/4-in-to-3-in-cast-iron-plastic-copper-steel-or-lead-pipe-flexible-coupling/977091
As long as the 3" side will fit over the MAF that's great. And if the 4" side is actually larger then it will fit over the TB no problem but hopefully it won't be too wide (although the clamps would tighten it either way).

I still like that reducer with the bulge in the middle ( http://intakehoses.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=4H35&Category_Code=RHH8 ). This one looks ideal for those of us who need to bend the coupler to correct the downward angle from the lid.

On the 4" side the Fernco would have a minimum of a 4.5" inside diameter, (maybe even slightly larger?).:nod:

As for that being TOO wide, remember the 3.5" inside diameter 3" Fernco coupler and be "forced" over the OVAL throttle body quite nicely, a 4.5" inside diameter round rubber coupler end would be significanly larger than the LT1 throttle body "oval".

I have no idea why people are using couplers from the MAF-Lid considering lids were designed to have the maf slid into them. :confused:

They designed ls1 lids to accept an lt1 maf? That's surprising....I tried to connect my slp lid to my lt1 maf and they wouldn't fit. I had to really force it in there, and it didn't want to stay there. I was afraid I would break the lid. I also trimmed the opening to correct the angle a bit. Before and after the trimming it didn't fit too well though. I thought the flexible bellow made a much better and cleaner connection.

I have no idea why people are using couplers from the MAF-Lid considering lids were designed to have the maf slid into them. :confused:

I agree 100% with this statement!:nod: My 3.5" outside diameter LT1 MAF sensor ....... fit perfectly within my SLP LS1 lid!!!:nod::nod:

They designed ls1 lids to accept an lt1 maf? That's surprising....I tried to connect my slp lid to my lt1 maf and they wouldn't fit. I had to really force it in there, and it didn't want to stay there. I was afraid I would break the lid. I also trimmed the opening to correct the angle a bit. Before and after the trimming it didn't fit too well though. I thought the flexible bellow made a much better and cleaner connection.

GREGG 97, I have NO idea what may be going on here, but, like I said above, my SLP LS1 aftermarket lid fit my LT1 MAF sensor ......... perfectly! No cutting of the lid required at all!:D

^^^Mine didn't? :confused: I bought it new for a 99 ls1 from slp about 2 years ago. maybe they changed something cause mine would not fit easily at all. Then it was much worse fit after I cut the opening to correct the angle. That's when I decided to use my rubber bellow connector.

I found one at Home Depot

http://i31.photobucket.com/albums/c360/streetwarrior96/airlid.jpg

No, it's just 1/2 of a 3" fernco coupler. If you heat it up for a few minutes in a pot of hot water it gets very soft and flexible, then you can quickly put it on the tb. It will mold to the oval shape of the tb very easily. Them connect the maf to it, that fits easily on it. From the maf to tb is part of my old intake bellow, it makes a nice connector when you cut it off the rubber elbow and trim it a bit.

No shit huh. So its this $10 piece http://www.homedepot.ca/product/3-in-cast-iron-plastic-copper-steel-or-lead-pipe-flexible-coupling/977090
I'll be picking up one on the way home. And I get what you're saying 97 6sp that the 4" would likely be too big for the TB opening (its interesting that Fernco's numbers aren't representative of the diameter of the couplers. Most silicone type couplers are, which is why I figured we needed 3.5" to 4" couplers for our cars. But I guess a 3.5" diameter coupler can be stretched to fit the TB anyways.

I have no idea why people are using couplers from the MAF-Lid considering lids were designed to have the maf slid into them

Those of us LT1 guys who do the proper LS1 lid conversion (not cutting out the base) end up having the open end of the lid sitting much higher than the level of the TB. So some guys need to use flexible coupler from the lid to the MAF and a second one to the TB in order to form a bent pathway. The trick is forming a pathway that's seamless and without any major kinks or folds in the coupler.

I always assumed/believed the MAF's could slide right into the lid openings. They should. My MAF slid right into my LT1 Firehawk ram air box. The problem though is IF you need to fix the height or angle coming from the lid/box opening to the TB opening, its harder to do with the MAF inserted directly into the lid b/c it basically continues that same incorrect angle (or in the case of my firehawk box, it continues the incorrect height). If you only leave yourself one coupler from the MAF to TB to play with, if the height or angle is off enough you will end up with a nasty bend or kink in that coupler in order to mate them. With an additional coupler (even short one) from the lid/box opening to the MAF, it gives you an extra piece to gently bend or flex so that you can do less bending/flexing with the MAF to TB coupler.

They designed ls1 lids to accept an lt1 maf? That's surprising....I tried to connect my slp lid to my lt1 maf and they wouldn't fit. I had to really force it in there, and it didn't want to stay there. I was afraid I would break the lid. I also trimmed the opening to correct the angle a bit. Before and after the trimming it didn't fit too well though. I thought the flexible bellow made a much better and cleaner connection.

Considering LT1 MAF's and LS1 MAF's are the same yes.

Those of us LT1 guys who do the proper LS1 lid conversion (not cutting out the base) end up having the open end of the lid sitting much higher than the level of the TB. So some guys need to use flexible coupler from the lid to the MAF and a second one to the TB in order to form a bent pathway. The trick is forming a pathway that's seamless and without any major kinks or folds in the coupler.

That's how it is on LS1's too, and that's why I bought the correct coupler I linked earlier in this thread instead of the POS home depot one.

http://i86.photobucket.com/albums/k106/spddmn24/IMAG0175.jpg

http://i86.photobucket.com/albums/k106/spddmn24/IMAG0176.jpg