Dead spot with SuperRam
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 2,295
Likes: 14
From: Grand Sport #82
Dead spot with SuperRam
Today was the first day that i rally had a chance to try out and do some performnce measurements on my winter mods projects.
Since we dont have drag strip here, I measure my gain with a simple 0-200 Kmh run. (124,3 Mph).
My new mods are:
SuperRam (Runner/plennum)
AIR delete
1.6 Promagnums, with Compcams pushrods/guideplates
BBK AFPR (set at 51 psi)
I have a total improvment of 3 seconds on the 0-200 run,(20,3 sec), BUT I have a dead spot around 2000-2500 rpms, that I dident have before. You can fell that it dosent pull as strong in that area as elsewere.
What could cause that "dead spot"
Could be be some "tuning" issues?
Also i know that my times could be faster if i raise my shift points a bit
Since we dont have drag strip here, I measure my gain with a simple 0-200 Kmh run. (124,3 Mph).
My new mods are:
SuperRam (Runner/plennum)
AIR delete
1.6 Promagnums, with Compcams pushrods/guideplates
BBK AFPR (set at 51 psi)
I have a total improvment of 3 seconds on the 0-200 run,(20,3 sec), BUT I have a dead spot around 2000-2500 rpms, that I dident have before. You can fell that it dosent pull as strong in that area as elsewere.
What could cause that "dead spot"
Could be be some "tuning" issues?
Also i know that my times could be faster if i raise my shift points a bit
Last edited by Lars87; Mar 28, 2007 at 11:00 AM.
Melting Slicks
Joined: Aug 2003
Posts: 3,395
Likes: 393
From: Lakeville MI
Lars,
My car picks up about 50 lb. ft. of torque between 2000 and 2500 rpm. So the torque is definately down below 2500 rpm.
Some of this is due to the SR and some of it is due to the camshaft in my case.
The long tube runners are probably better in this rpm range than the SR since the ram effect comes on sooner maybe 2400-2800 rpm.
With stock chip tuning you may be slighty rich under 2500 rpm since the PE is increasing from 0 to 3.1 % between 2000 and 2400 rpm to suit the tpi intake. The SR isn't really providing any ram effect yet.
You may see some benefit with tuning, but I wouldn't expect big gains in this area.
My car picks up about 50 lb. ft. of torque between 2000 and 2500 rpm. So the torque is definately down below 2500 rpm.
Some of this is due to the SR and some of it is due to the camshaft in my case.
The long tube runners are probably better in this rpm range than the SR since the ram effect comes on sooner maybe 2400-2800 rpm.
With stock chip tuning you may be slighty rich under 2500 rpm since the PE is increasing from 0 to 3.1 % between 2000 and 2400 rpm to suit the tpi intake. The SR isn't really providing any ram effect yet.
You may see some benefit with tuning, but I wouldn't expect big gains in this area.
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 2,295
Likes: 14
From: Grand Sport #82
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 2,295
Likes: 14
From: Grand Sport #82
Lars,
My car picks up about 50 lb. ft. of torque between 2000 and 2500 rpm. So the torque is definately down below 2500 rpm.
Some of this is due to the SR and some of it is due to the camshaft in my case.
The long tube runners are probably better in this rpm range than the SR since the ram effect comes on sooner maybe 2400-2800 rpm.
With stock chip tuning you may be slighty rich under 2500 rpm since the PE is increasing from 0 to 3.1 % between 2000 and 2400 rpm to suit the tpi intake. The SR isn't really providing any ram effect yet.
You may see some benefit with tuning, but I wouldn't expect big gains in this area.
My car picks up about 50 lb. ft. of torque between 2000 and 2500 rpm. So the torque is definately down below 2500 rpm.
Some of this is due to the SR and some of it is due to the camshaft in my case.
The long tube runners are probably better in this rpm range than the SR since the ram effect comes on sooner maybe 2400-2800 rpm.
With stock chip tuning you may be slighty rich under 2500 rpm since the PE is increasing from 0 to 3.1 % between 2000 and 2400 rpm to suit the tpi intake. The SR isn't really providing any ram effect yet.
You may see some benefit with tuning, but I wouldn't expect big gains in this area.
Good info thanks.
Well overall the car IS quicker.
What metodes/ mods would be the solution to this?
Melting Slicks
Joined: Aug 2003
Posts: 3,395
Likes: 393
From: Lakeville MI
Back off the fuel pressure to 46-48 psi.
No need for extra fuel pressure unless you're outflowing the MAF capability, have changed injectors, or have made adjustments in the chip to utilize greater fuel pressure in order to reduce injector duty cycle.
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 2,295
Likes: 14
From: Grand Sport #82
Would to high FP cause a dead spot/rich situation at some rpms
Last edited by Lars87; Mar 28, 2007 at 12:49 PM.
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If you havent changed the cam, then i'd play with the pressure and timing a little more, thats too much pressure.
But a chip will do best.
But a chip will do best.
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 2,295
Likes: 14
From: Grand Sport #82
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 2,295
Likes: 14
From: Grand Sport #82
So did some tune up today.
Set the AFPR to 47 PSI (vac off)
Adjustet TPS, and IAC
Timing set to 8 deg BTDC. (it was only at 4 deg BTDC before)
All in all the throttle response is improvet alot, The car pulls slight harder at 4000-5000 area, and the dead spot isent SO dead anymore..
The car absolutly pulls harder after 2800 rpms, but that should be the case with the Super Ram. Great feel when the car pulls strong and even from 2800 - 5500
Set the AFPR to 47 PSI (vac off)
Adjustet TPS, and IAC
Timing set to 8 deg BTDC. (it was only at 4 deg BTDC before)
All in all the throttle response is improvet alot, The car pulls slight harder at 4000-5000 area, and the dead spot isent SO dead anymore..
The car absolutly pulls harder after 2800 rpms, but that should be the case with the Super Ram. Great feel when the car pulls strong and even from 2800 - 5500
Team Owner
Joined: Sep 2002
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From: OBAMA IS HITLER
lars, adding a cam in the equation will create an interesting effect where you'll get 2 power surges, one nice one when the SR kicks in and another even stronger spike at the mid-4,000 rpm up to redline -- that'll help get the rocks off.
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 2,295
Likes: 14
From: Grand Sport #82
