Carb Spacers Updated?
Thread Starter
Drifting
Joined: Apr 2002
Posts: 1,743
Likes: 37
From: Stockton Ca
Lost Power?
From the info posted, it looks like most of us are closing the hood on
15-20 hp? Not to mention the increase in mpg.
The only downside of an L88 hood that I can see is when it rains.
That I can handle w/cover. I hope some of these ideas are being tested as we speak, and the results will be posted? TIA
R
15-20 hp? Not to mention the increase in mpg.
The only downside of an L88 hood that I can see is when it rains.
That I can handle w/cover. I hope some of these ideas are being tested as we speak, and the results will be posted? TIA
R
Race Director
Joined: Oct 2000
Posts: 15,057
Likes: 79
From: central FL, near the beach.
From the info posted, it looks like most of us are closing the hood on
15-20 hp? Not to mention the increase in mpg.
The only downside of an L88 hood that I can see is when it rains.
That I can handle w/cover. I hope some of these ideas are being tested as we speak, and the results will be posted? TIA
R
15-20 hp? Not to mention the increase in mpg.
The only downside of an L88 hood that I can see is when it rains.
That I can handle w/cover. I hope some of these ideas are being tested as we speak, and the results will be posted? TIA
R
Rain? should not come in while driving; maybe a few sprinkles
Race Director
Joined: May 2003
Posts: 10,956
Likes: 409
From: California
A little update on the spacer thing....
Went to CMS and saw Ryan today. We did a dyno run with the 4 hole spacer and then I cut out the 4 holes and put the spacer back
in.... 10+ hp gain at upper end..... there you have it.... dyno tested....
my tq was 436 ft
Went to CMS and saw Ryan today. We did a dyno run with the 4 hole spacer and then I cut out the 4 holes and put the spacer back
in.... 10+ hp gain at upper end..... there you have it.... dyno tested....my tq was 436 ft
Last edited by pauldana; Nov 28, 2009 at 08:06 PM.
Thread Starter
Drifting
Joined: Apr 2002
Posts: 1,743
Likes: 37
From: Stockton Ca
Matt: I mean that w/o carb insulation and or carb spacer and CAI, most of us are losing 15-20 hp when we close the hood. The hot air would also decrease mpg. Does that make sense?
As far as increasing DCR w/CAI, that's for smarter people than I.
I run the optimum 32* w/19* initial. No problems so far.
R
As far as increasing DCR w/CAI, that's for smarter people than I.
I run the optimum 32* w/19* initial. No problems so far.
R
Race Director
Joined: Oct 2000
Posts: 15,057
Likes: 79
From: central FL, near the beach.
R
i tested the mpg before and after CAI, no change.
the carb isolator can stop boiling, and if it is open it can ruin mpg, a drop of 7 or 8 mpg in my case. OTOH removing an aluminum open spacer and adding a 4 hole gasket or wood 4 hole spacer can stop boiling and add mpg. A very critical area to mess with!
.
paul
I'd be interested to see a 4 hole spacer on top of a 4 hole gasket, vs. just a 4 hole gasket. And then for racing, removing both of them, and using a 1/4" open gasket. I'd like to see cruising torque and idle torque on all of the tests for an indication of street manners.
if your spacer, now cut open, is for drag racing, the Q is, does it turn a better time cut open? If so, then i'd use it at the track only. Losing 7-8 mpg for 10hp is an awful trade for the street. I'd want like 900 HP to drop that much mpg. Like a big blown BB.
But, different combos react differently so u should do more testing to evaluate a change. dyno vs track vs street manners vs mpg .
If anyone wants to see how easy it is to lose 7 or 8 mpg see my article http://community-2.webtv.net/MATTGRU/carb
i tested the mpg before and after CAI, no change.
the carb isolator can stop boiling, and if it is open it can ruin mpg, a drop of 7 or 8 mpg in my case. OTOH removing an aluminum open spacer and adding a 4 hole gasket or wood 4 hole spacer can stop boiling and add mpg. A very critical area to mess with!
.
paul
I'd be interested to see a 4 hole spacer on top of a 4 hole gasket, vs. just a 4 hole gasket. And then for racing, removing both of them, and using a 1/4" open gasket. I'd like to see cruising torque and idle torque on all of the tests for an indication of street manners.
if your spacer, now cut open, is for drag racing, the Q is, does it turn a better time cut open? If so, then i'd use it at the track only. Losing 7-8 mpg for 10hp is an awful trade for the street. I'd want like 900 HP to drop that much mpg. Like a big blown BB.
But, different combos react differently so u should do more testing to evaluate a change. dyno vs track vs street manners vs mpg .
If anyone wants to see how easy it is to lose 7 or 8 mpg see my article http://community-2.webtv.net/MATTGRU/carb
Last edited by Matt Gruber; Nov 29, 2009 at 09:57 AM.
Team Owner
Joined: Apr 2002
Posts: 62,198
Likes: 1
From: All humans are vermin in the eyes of Guru VA
Cruise-In IV Veteran
Cruise-In V Veteran
intakes are just like headers. The runners should be a certain length, with a certain cross sectional area, and the plenum needs a certain volume based upon your displacement and RPM range.
A spacer can increase that plenum volume if its necessary.
There are some other specialized products by people like HVHand wilson manifolds that focus on the carb to manifold transition.
So its a tuning aide.
A spacer can increase that plenum volume if its necessary.
There are some other specialized products by people like HVHand wilson manifolds that focus on the carb to manifold transition.
So its a tuning aide.
