Supercharging an L27

[DiscoStudd]

I read this over at L67swap.com

 

 

All of you out there with a series 1 3.8 might be pleased to know(if you didnt already) that you can add power to your n/a engine without having to swap to a series 2. First i would like to say that i own a 1990 oldsmobile toranado trofeo and a 1998gtp and i love them both! I looked into upgrades for the series 1 and they just we not there. im not tring to get 400HP so i did some reasurch(my gtp is for 400HP! )Un like the series 2 the series one CAN be supercharged using a 1992-1995 eaton m62.you dont nead to replace the head like on the series 3(the blower is smaller and the fuel injectors go into the intake not bosses in the heads) Of course you will nead the pully asembley,crankshaft balencer(double pully groves) In general it is a straight forward swap and your stock trany and bottom end will hold up.the compressoin for a n/a series 1 and supercharged 92-95 was both 8.5.1 and your injectors are 28lb./hr on your supercharged intake. Upgrade fuel pump,and the rest is up to you. I figure(correct me if im wrong) but a lightly modded series one 3.8L should be able to handle 230-260hp. All the internal parts were the same for the n/a -supercharged motors except the conecting rods.I hope this is helpfull to those who want a cost effective alternative to swaping for a series 2 and custom wiring jobs. I found my series 1 for $400.00 and never looked back!

 

I haven't been able to find any more info on the matter (I don't exactly want to join their message board either. All the newbies ask the same questions over and over and the answers seem to be vague...)

 

I'd like to get some feedback from the W-Body community as to whether or not this is possible. If so, what have any of you heard or seen? All I'm really after is an answer as to whether this is simply a bolt-on deal, or if the computer needs to be changed, or what. I'm thinking if this guy is for real, then this would be a cheap alternative to an L67. If it's more complicated than he says, then I guess it's L67 time for me (eventually...)

 

Comments would be greatly appreciated. Thanks!

[patgizz]

im not sure it would be a cheap alternative, when the LKQ yard by me gets L67's they put them on ebay for $400 no reserve and ive seen them sell as low as 495 with harness and ecm.

[rudefyet]

It is possible they made an Series I L67 used in the Bonneville SSEi

 

All you would need to do is the intake manifold, supercharger, memcal, and any other parts that differ from an L27 from one and you can supercharge it

 

I believe stock output for the SI L67 is 205hp...but i'm sure that can be tweaked

[99RegalGS]

The 88-92 3800's have a 8.5:1 Compression, but 93-95 3800's have 9:1. But he is correct that the block and heads are the same between the 2.

I was planning on doing something like this to my Regal untill I decided to get the Cutty.

 

I believe stock output for the SI L67 is 205hp...but i'm sure that can be tweaked

Yes, and no. The 92,93 L67 is 205hp/265tq. But the 94,95 L67 is 225hp/275tq. So I reccomend getting a 94,95 S/C. and actually the stock 92,93 pulley is smaller than the 94,95. So you could get a pulley off a 92,93 S/C and put it on the 94,95 S/C to give it more power.

 

I have done some research so if you have any more questions just ask.

[DiscoStudd]

The 88-92 3800's have a 8.5:1 Compression, but 93-95 3800's have 9:1. But he is correct that the block and heads are the same between the 2.

I was planning on doing something like this to my Regal untill I decided to get the Cutty.

 

I believe stock output for the SI L67 is 205hp...but i'm sure that can be tweaked

Yes, and no. The 92,93 L67 is 205hp/265tq. But the 94,95 L67 is 225hp/275tq. So I reccomend getting a 94,95 S/C. and actually the stock 92,93 pulley is smaller than the 94,95. So you could get a pulley off a 92,93 S/C and put it on the 94,95 S/C to give it more power.

 

I have done some research so if you have any more questions just ask.

 

So maybe I could lower the compression the old fashioned way by using a thicker head gasket, or would 9:1 be okay? The consensus here is that it is a direct bolt in, so what has to be done to the PCM? Does the MEMCAL need to be swapped? I would imagine an N/A L27 PCM would have a fit with the SC bolted to the top of it. Since the W-Bodies never had the Series I L67, I would assume I'd need a custom chip. As long as the wiring could go untouched, this is something I'm very interested in doing. I suppose that whenever I grenade either the motor or the tranny after adding the SC, then I could do the L67 swap for real...

 

Thanks for the advice, gentlemen!

[99RegalGS]

9:1 compression should be fine as long as you don't turn the boost up to high.

 

Actually I'm not sure if anything has to be done to the PCM since the L27 is based on a MAF system (like the GN and T-types). so the computer should reconize the extra air and compensate.

 

I think the engine should be fine with a S/C on it. I was also worried about the tranny. But I was going to go for it anyway.

[DiscoStudd]

9:1 compression should be fine as long as you don't turn the boost up to high.

 

Actually I'm not sure if anything has to be done to the PCM since the L27 is based on a MAF system (like the GN and T-types). so the computer should reconize the extra air and compensate.

 

I think the engine should be fine with a S/C on it. I was also worried about the tranny. But I was going to go for it anyway.

 

 

Ok, that make sense about the MAF system. I was just pondering the tranny issue myself on my way home from work. I think I remember reading somewhere that the 4T60E could be beefed up a bit. Maybe I'll just get the tranny rebuilt for good measure. I wonder if keeping the CR at 9:1 and using the smaller pulley from the 92-93 SC would turn the boost up to the point of the ECM retarding the spark?

[99RegalGS]

The 4T60-E did have a HD version which was used on the L67 and the L26.

 

If I was going to do the S/C I wasn't going to put the smaller pulley on because I wasn't sure if it would detonate or not.

 

And BTW one of the differences on the L67 chip is a timing retard. IIRC it was around 4*.

[brianteel]

To use any supercharged motor in a w-body you have to reprgram the PCM or change the engine harness. The harderest thing about swapping the series 2 if you are interested in that is making the wiring adapter which is not even that hard.

 

I am sure it is bolt in with the correct engine mounts.

 

why would you want to go with the older motor if there are 2 newer versions with much more power.

[99RegalGS]

To use any supercharged motor in a w-body you have to reprgram the PCM or change the engine harness

From what I know the differences are ~4* timing retard and a wastegate control. As far as fuel, the MAF will handle it.

 

why would you want to go with the older motor if there are 2 newer versions with much more power.

This way you don't have to take the engine out. And from the 94,95 S/C to the SII L67 there is only 15hp and 5tq difference. Then put on the 92,93 pulley and it will have close to equal power. Not bad for an older engine with a smaller supercharger.

[brianteel]

not bad at all. what other info do you have about this motor.

[99RegalGS]

I know a bit.

 

Just ask. And I'll see if I can help.

[DiscoStudd]

why would you want to go with the older motor if there are 2 newer versions with much more power.

 

I actually want to swap in the newer L67 at some point, but if going this route is a cheaper and easier proposition, it makes sense to me to do it.

 

This way you don't have to take the engine out. And from the 94,95 S/C to the SII L67 there is only 15hp and 5tq difference. Then put on the 92,93 pulley and it will have close to equal power. Not bad for an older engine with a smaller supercharger.

 

My thoughts exactly. Also you don't have to hassle with rewiring the whole thing and worry about compatibility with the car. Another thing: making the custom axles. I'm kinda leery of having a "hybrid" system on my daily driver. I, myself, want to do the actual L67 swap when I have another car for a daily driver, that way I can iron out the bugs on my own time and not worry about the car being down for long periods of time. Also if I could find a used 4T60-E HD tranny on the cheap (yeah I know a fresh one is $3500,) maybe I wouldn't have to worry about the axle swap issue.

 

Now getting the OBDII L67 to run on the stock 95 Regal's OBDI computer, and hooking it up to a 4T60-E HD would be sweet...

[99RegalGS]

Now getting the OBDII L67 to run on the stock 95 Regal's OBDI computer, and hooking it up to a 4T60-E HD would be sweet...

I know people have run series 2 L67's on series 1 L67 computers. so it sounds very possible.

[brianteel]

you can definitly run series 2 motors with the series 1 wiring. the fiero guys do it all the time.

 

as for axles and wiring: It is not as bad as you think right now someone i know is coming up with custom axles for 140 a set and i can wiring the engine into almost any GM car and beyond.

 

I would love for some guys with some knowledge of the series 1 motors to go to L67swap.com. I actually own and run the site.

 

I know alot about how do to the swap and i have done many my self. The hardest thing is the wiring but it is only 20 wires and the chart on how to wire it up is on the site.

[99RegalGS]

I just signed up at l67swap.com forums.

[brianteel]

awsome.....

[DiscoStudd]

Check this out:

 

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33741&item=2477176272&rd=1

 

Now if only I could convince the wifey that it would be a good investment for the 3 bills ... It'd probably collect dust for about a year anyways. Gotta wait until we have our new house and another car before I tear into "The StuddMobile."

 

I'll most likely join up over at L67swap when I get close to doing the swap myself. I've got a million questions, and nobody's documented or photographed their swap yet. Maybe I'll have someone taking pictures when I do mine. I will definitely document it...

[99RegalGS]

That's perfect for this. All you would need to get then are the harmonic balancer and the relocation of the PS pump and the alt. then the tentioners.

[DiscoStudd]

I bought it! I'm just waiting for the guy to e-mail me back with the shipping charges. My wife didn't need much convincing, either! I was looking at Car-Part.com and most yards wanted $450 just for the Supercharger alone. This sucker's complete for only 3 bills. Can't wait until we have the new house, now. As soon as I have my garage, it's project time!!!

[99RegalGS]

SWEET!!!

 

hope you get in on soon.

[DiscoStudd]

Now I just need to decide where I will get my chip from.

GMTuners.com or

FastChip

 

Gotta hunt down the front accessory assembly from a Series I L67 and the crank pulley like you said, also.

 

I suppose I should throw in a new radiator for good measure. Probably a trans cooler, too. Let's see, beef up the tranny, 2.5" exhaust, Walboro fuel pump. Shit this is going to be spendy !!!

[DiscoStudd]

I was checking out CarPart.com, thinking a chip from an L67 95 Riviera would work in my Regal. Turns out there is only one ECM/Chip combo for both the L27 and L67. Of course the Regal has a different ECM due to it being mounted under hood. The ECM's that popped up for the Riv on the search ran the gamut from Bonnevilles, 88's, 98's, Park Ave's, Trans Sports (basically every 3800 that wasn't in a W-Body.) I'm guessing I don't need a custom chip afterall...

[99RegalGS]

There is difference between the Regal and the Rivera ECM but it's only that the Regal ECM is water proof while the Rivera one isn't. That's why the part # is different. The internals are the same.

 

I don't think you need a new radiator, since the engine will only put out the extra heat when it's getting boost and you will probably be moving. but when it's not getting boost (ie idle crusing) it's putting out the same heat as an L27.

 

I was going to get the trans cooler also.

 

yeah, a bigger exhaust and a higher flow fuel pump will probably help.

[DiscoStudd]

There is difference between the Regal and the Rivera ECM but it's only that the Regal ECM is water proof while the Rivera one isn't. That's why the part # is different. The internals are the same.

I found that out the hard way a couple of years ago when I was looking for an ECM for my old LeSabre. I found a Regal with a 3800 and tore apart the dash looking for the ECM. I happened to look under the hood and found it there. Needless to say, its WeatherPack connectors wouldn't plug up to the LeSabre's harness. I was thinking about snatching only the chip out of a Riv ECM this time, but it doesn't look like there's a difference.

 

I don't think you need a new radiator, since the engine will only put out the extra heat when it's getting boost and you will probably be moving. but when it's not getting boost (ie idle crusing) it's putting out the same heat as an L27.

I'll do that just because it's a good idea to replace a 9 year old radiator with over 160K. The Rads they sell at NAPA have a bit more surface area than a stocker, too. Erring on the side of "more cooling" (esp. with a supercharger) is better than "more heat" for sure...