Sluggish performance... here's why
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 3,277
Likes: 32
From: Mission Viejo California
Sluggish performance... here's why
I knew that my 87mph trap speed was showing that something was wrong. I ended up changing the plugs and can run much less on the btm. Also, I hooked up a boost guage today and I saw a high of 4lbs in 60* air temps. Right now I have a 4 rib belt on there. my guess is that it was put on there to control detonation with the stock heat range plugs that were in there originally since you'll never see more than 5 lbs with this setup.
On the to do list is change the belt and install the blower works inlet vane....
On the to do list is change the belt and install the blower works inlet vane....
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Originally Posted by qwiketz
I have since pulled it back to 1.5* and have no problems. All the good stuff is there on this motor. I just need to fine tune things.
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 3,277
Likes: 32
From: Mission Viejo California
Yup, believe it or not, there is a 4 rib belt on there. The only cars that use a 4 rib vortech are the honda setups. My guess is that the mechanic saw detonation when he tuned up the car using the stock heat range plugs, so he tried to limit the amount of boost that the engine saw by creating belt slip. The car has a built motor with 9.75 compression. When I first got it, I had to put the btm over 2 to get it to stop pinging on 91octane.
Since I picked up the car, I changed out the plugs to the champion 7401's. This helped the detonation problem considerbly. I don't think I've heard any since I changed them.
TJ, how long did it take you to change the belt on your car when you broke it?
Since I picked up the car, I changed out the plugs to the champion 7401's. This helped the detonation problem considerbly. I don't think I've heard any since I changed them.
TJ, how long did it take you to change the belt on your car when you broke it?
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 3,277
Likes: 32
From: Mission Viejo California
Yeah, I think what happened was the mechanic where the guy was located never really delt with a vette like this. I'm in the process of changing back all the junk he did to the car like the plugs and the belt.
With only 4lbs of boost and having to run so much retard, the car would probably run just as good without the blower even on there. I think it was Jim Bell of Kenne/Bell that said 1* of timing was equal to approximately 15hp or so. With 2*+ of timing retard, it pretty much negates the hp effects of the blower. I can't wait to get 10+ lbs of boost with full timing through this 383 (via water/alcohol injection). It's going to be one hell of a beast!
With only 4lbs of boost and having to run so much retard, the car would probably run just as good without the blower even on there. I think it was Jim Bell of Kenne/Bell that said 1* of timing was equal to approximately 15hp or so. With 2*+ of timing retard, it pretty much negates the hp effects of the blower. I can't wait to get 10+ lbs of boost with full timing through this 383 (via water/alcohol injection). It's going to be one hell of a beast!
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Melting Slicks
Joined: Dec 2000
Posts: 2,719
Likes: 60
From: Fremont Oh
When you get the injection system on your car and the fuel dialed in you'll be cracking the whip!
I was able to get back 5 degrees of timing on the top end ... so far! Just with the water / alky injection system I'm running about 27 degrees at 6000 rpm... vice 22
I'm even now hitting 12 pounds of boost at 6000 RPM
I'm still getting the fuel dialed in, but was able to drop my AFR from like 930's to now ~ 900 looking to drop to 850...
Good luck on the projects....
To change out the belt takes about an hour or so, and a REALLY STRONG arm it is or can be a real pain in the bottom...
Mo
I was able to get back 5 degrees of timing on the top end ... so far! Just with the water / alky injection system I'm running about 27 degrees at 6000 rpm... vice 22
I'm even now hitting 12 pounds of boost at 6000 RPM
I'm still getting the fuel dialed in, but was able to drop my AFR from like 930's to now ~ 900 looking to drop to 850...
Good luck on the projects....
To change out the belt takes about an hour or so, and a REALLY STRONG arm it is or can be a real pain in the bottom...
Mo
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 3,277
Likes: 32
From: Mission Viejo California
I'm really not looking forward to changing the belt. It's so tight in there that I can barely even see the tensioner pulley, much less imagine trying to get it tightened down on the belt.
12lbs of boost? You're probably over 500hp now. I can't wait to get some good boost numbers popping up on the guage. It'll make for a fun daily commute and some really bald pzero's!
12lbs of boost? You're probably over 500hp now. I can't wait to get some good boost numbers popping up on the guage. It'll make for a fun daily commute and some really bald pzero's!
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 3,277
Likes: 32
From: Mission Viejo California
mo's running a 7 rib setup off the early vortech kits with the 3.12 pulley and the blowerworks vane. I was just outside looking at my blower to figure out how this stuff is going to work when I'm pulling the head unit. I'm going to download the instructions, but anyone remember off the top of their head how many bolts hold the head unit in place? BTW, I'm not looking forward to this. I can see scraped up knuckles in my future.
Melting Slicks
Joined: Dec 2000
Posts: 2,719
Likes: 60
From: Fremont Oh
Quicketz is correct 7 rib with a 3.125... I also have a modified intake nozzle which has definately added 2 pounds of boost.
I am hitting 56 ls/min ~425 gm/sec airflow... I guess it's time to step up to 50/50 methanol and water. HEH
Based on the Airflow measurements about 522 horse.. It's about dyno time...
I'm not seeing any dusting around the belt, it really sounds different once it seems to go past 10# maybe thats the rev limiter
I'm one for an easier belt change method...
mo
I am hitting 56 ls/min ~425 gm/sec airflow... I guess it's time to step up to 50/50 methanol and water. HEH
Based on the Airflow measurements about 522 horse.. It's about dyno time...
I'm not seeing any dusting around the belt, it really sounds different once it seems to go past 10# maybe thats the rev limiter
I'm one for an easier belt change method...
mo
Pro
Joined: Aug 2004
Posts: 544
Likes: 0
Originally Posted by Mo_Bandy
Quicketz is correct 7 rib with a 3.125... I also have a modified intake nozzle which has definately added 2 pounds of boost.
I am hitting 56 ls/min ~425 gm/sec airflow... I guess it's time to step up to 50/50 methanol and water. HEH
Based on the Airflow measurements about 522 horse.. It's about dyno time...
I'm not seeing any dusting around the belt, it really sounds different once it seems to go past 10# maybe thats the rev limiter
I'm one for an easier belt change method...
mo
I am hitting 56 ls/min ~425 gm/sec airflow... I guess it's time to step up to 50/50 methanol and water. HEH
Based on the Airflow measurements about 522 horse.. It's about dyno time...
I'm not seeing any dusting around the belt, it really sounds different once it seems to go past 10# maybe thats the rev limiter
I'm one for an easier belt change method...
mo
Melting Slicks
Joined: Mar 1999
Posts: 2,535
Likes: 2
From: Rochester NY
hell yeah it sound different when under boost. My old 383LT1 combo hit 14.2psi of boost on the dyno with a "untuned" chip. Shot down at 4600rpm and 544rwhp,598rwt. The sound of the motor is scary.
Bruce
Bruce
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 3,277
Likes: 32
From: Mission Viejo California
wow, I don't feel so bad about the 87mph trap speed now. I'm only seeing 1.5-2lbs of boost once the belt starts slipping above 4000 rpm and about 3.5-4.0 lbs up to that point.
BTW, picked up a stage 2 snow kit off a mustang guy that wrecked his car. I mocked it up today. The salvage guy only charged me $125 for the complete setup. Talk about a score!
BTW, picked up a stage 2 snow kit off a mustang guy that wrecked his car. I mocked it up today. The salvage guy only charged me $125 for the complete setup. Talk about a score!