S1 3800 (L27) heads - Page 3 - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Performance, Brainstorming & Tuning Talk about modifications, or anything else associated with performance enhancements. Have a new idea for performance/reliability? Post it here. No idea is stupid! (please use Detailing and Appearance for cosmetic ideas)

Reply
 
 
 
Thread Tools Search this Thread
Old 02-13-2010, 02:44 PM   #21
Senior Member
True Car Nut
Thread Starter
 
xtremerevolution's Avatar
 
Join Date: Jun 2007
Location: New Lenox, IL
Posts: 2,478
Thanks: 0
Thanked 0 Times in 0 Posts
xtremerevolution is on a distinguished road
Default

Quote:
Originally Posted by 95naSTA View Post
I would definitely bet on it and I don't gamble.

It'* essentially the same thing as a less dramatic HV3 on an L36. The HV3 takes about 3 inches or so off of the total intake runner length and really wakes the car up if you have a cam.

I suggested just making your L27 runners 1 inch shorter so that you are not making that drastic of a change.
Sweet deal man. I'll do this today and get back to you on the results. Can't wait.

I've been trying left and right to wake up this engine a bit and nothing has made a big difference. Hopefully this small modification will bring out the potential of the rockers, CAI, exhaust, and ported Lim I have on there. hi5.

I'll get back to this thread later tonight on how it all works out.
xtremerevolution is offline   Reply With Quote
Old 02-14-2010, 05:34 PM   #22
Senior Member
True Car Nut
Thread Starter
 
xtremerevolution's Avatar
 
Join Date: Jun 2007
Location: New Lenox, IL
Posts: 2,478
Thanks: 0
Thanked 0 Times in 0 Posts
xtremerevolution is on a distinguished road
Default

So I've done it all. Is this what you were telling me to do?

Name:  2010-02-13200348.jpg
Views: 5
Size:  62.3 KB

I put it back in, went out for a drive, and noticed a slight increase in top end power. Not sure if its just me thinking there was an increase, but there certainly wasn't a decrease.

Perhaps I have to drive more to let the PCM get used to the changes. I didn't disconnect the battery after I did this. Should I have?

Last edited by xtremerevolution; 02-14-2010 at 05:36 PM.
xtremerevolution is offline   Reply With Quote
Old 02-14-2010, 07:02 PM   #23
Senior Member
True Car Nut
 
95naSTA's Avatar
 
Join Date: Feb 2003
Location: Philly
Posts: 4,508
Thanks: 0
Thanked 0 Times in 0 Posts
95naSTA is on a distinguished road
Default

Yep, that'* what I was getting at. You could go further and remove the vertical sides of the runner that are perpendicular to the TB entrance.

In retrospect, I should have told you to scan for your maf flow vs. rpm at WOT before and after so you can see if you're pulling more air.

And as far as the pcm goes it wouldn't hurt but unless you're getting knock, you're probably at the mods peak potential.

Another thing is, if you can get a radius on the opening (especially near the center) you would get even more flow. You would be on your own for this though.

Last edited by 95naSTA; 02-14-2010 at 07:08 PM.
95naSTA is offline   Reply With Quote
Old 02-14-2010, 07:46 PM   #24
Senior Member
True Car Nut
Thread Starter
 
xtremerevolution's Avatar
 
Join Date: Jun 2007
Location: New Lenox, IL
Posts: 2,478
Thanks: 0
Thanked 0 Times in 0 Posts
xtremerevolution is on a distinguished road
Default

Quote:
Originally Posted by 95naSTA View Post
Yep, that'* what I was getting at. You could go further and remove the vertical sides of the runner that are perpendicular to the TB entrance.

In retrospect, I should have told you to scan for your maf flow vs. rpm at WOT before and after so you can see if you're pulling more air.

And as far as the pcm goes it wouldn't hurt but unless you're getting knock, you're probably at the mods peak potential.

Another thing is, if you can get a radius on the opening (especially near the center) you would get even more flow. You would be on your own for this though.
Sounds good. I'll cut off the sides and make a radius at the entrance tomorrow. I'm getting so damn fast at removing my UIM its not even funny. I think yesterday was the 4th time I've taken it off. I did it once to replace the LIM gaskets, a second time to attempt to fix a throttle body passage leak, a third time to do the same and have it fail, and the last time, during which I also plugged up the coolant passages because I got fed up with the UIM and the coolant leaking. I think I can get the whole thing off now in 15 minutes.

One big thing I noticed while looking at the L36 LIM. The runners on the L27 are a LOT longer.

Compare the two:

L36 LIM:
Name:  IMG_0290.jpg
Views: 6
Size:  90.4 KB

L27 LIM:
Name:  IMG_0361.jpg
Views: 7
Size:  95.9 KB

And to think that ZZP cut off 3" from their runners? Those are some extremely short runners.

Last edited by xtremerevolution; 02-14-2010 at 07:49 PM.
xtremerevolution is offline   Reply With Quote
Old 02-14-2010, 09:55 PM   #25
Senior Member
True Car Nut
 
95naSTA's Avatar
 
Join Date: Feb 2003
Location: Philly
Posts: 4,508
Thanks: 0
Thanked 0 Times in 0 Posts
95naSTA is on a distinguished road
Default

The L27 runners are longer in the LIM but the L36/L27 runners are longer in the UIM:

Name:  FSL26004.jpg
Views: 12
Size:  67.9 KB

And how do you plan to make a radius? epoxy?

Last edited by 95naSTA; 02-14-2010 at 09:56 PM.
95naSTA is offline   Reply With Quote
Old 02-14-2010, 10:03 PM   #26
Senior Member
True Car Nut
Thread Starter
 
xtremerevolution's Avatar
 
Join Date: Jun 2007
Location: New Lenox, IL
Posts: 2,478
Thanks: 0
Thanked 0 Times in 0 Posts
xtremerevolution is on a distinguished road
Default

Wait...what exactly do you mean when you say a radius?
xtremerevolution is offline   Reply With Quote
Old 02-14-2010, 11:06 PM   #27
Senior Member
True Car Nut
 
95naSTA's Avatar
 
Join Date: Feb 2003
Location: Philly
Posts: 4,508
Thanks: 0
Thanked 0 Times in 0 Posts
95naSTA is on a distinguished road
Default

Like a bellmouth.
95naSTA is offline   Reply With Quote
Old 02-15-2010, 01:29 AM   #28
Senior Member
True Car Nut
Thread Starter
 
xtremerevolution's Avatar
 
Join Date: Jun 2007
Location: New Lenox, IL
Posts: 2,478
Thanks: 0
Thanked 0 Times in 0 Posts
xtremerevolution is on a distinguished road
Default

Quote:
Originally Posted by 95naSTA View Post
Like a bellmouth.
Ah, gotcha.

I'll be thinking about that for a while.

Do you think its worth it to pull the UIM just to cut off the sides?

I'll have to some planning on a way to create that a bellmouth type attachment.
xtremerevolution is offline   Reply With Quote
Old 02-15-2010, 10:17 AM   #29
Senior Member
True Car Nut
 
95naSTA's Avatar
 
Join Date: Feb 2003
Location: Philly
Posts: 4,508
Thanks: 0
Thanked 0 Times in 0 Posts
95naSTA is on a distinguished road
Default

Maybe do some planing about bell-mouthing the entrance and cut the sides at the same time?
95naSTA is offline   Reply With Quote
Old 02-15-2010, 01:50 PM   #30
Senior Member
True Car Nut
Thread Starter
 
xtremerevolution's Avatar
 
Join Date: Jun 2007
Location: New Lenox, IL
Posts: 2,478
Thanks: 0
Thanked 0 Times in 0 Posts
xtremerevolution is on a distinguished road
Default

Quote:
Originally Posted by 95naSTA View Post
Maybe do some planing about bell-mouthing the entrance and cut the sides at the same time?
Sounds good. I have to change the oil on my Bonneville today anyway. 8 quarts of full synthetic ain't cheap.

I'll let you know what I come up with when the time comes.

Last edited by xtremerevolution; 02-15-2010 at 02:12 PM.
xtremerevolution is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
L27 Intake Manifold onto LN3 Heads- Granny's Delta Performance, Brainstorming & Tuning 14 04-08-2011 09:04 PM
are 3.8 L. heads interchangable with 4.3 L. heads? Hay Bay Woody General GM Chat 1 06-21-2010 06:32 PM
L27 heads - Rockers on 3/8 bolts xtremerevolution Performance, Brainstorming & Tuning 33 04-21-2010 11:25 PM
L27 heads on a LN3? OLBlueEyesBonne Performance, Brainstorming & Tuning 6 03-08-2005 07:29 PM
91 3800 heads and fuel injection swappable on 3.8L odd fire? 89SSE Performance, Brainstorming & Tuning 8 01-21-2005 05:53 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 01:33 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.