FIRST INJECTION pics
Racer
Joined: Oct 2007
Posts: 478
Likes: 1
Some tidbits of information. I'm using the First intake manifold, SLP runners and the factory TPI plenum. The motor is 355 cubic inches with the Comp Cams XFI268 cam. Dart 200cc Pro One heads and 10.72:1 compression.
This is through an A4 transmission and a Yank SS3600 stall with 3.70 gears. The best chasis dyno pull was 355rwhp at 5100rpm and 377rwtq around the 4700rpm mark. Torque converter was unlocked.
Using the 20% drivetrain loss that works out to around 440 horsepower at the motor and 470 ft/lb torque. I'm in the process of changing out the valve springs and going to a larger cam. I have been told by the "experts" that my cam is to small and the valve springs to weak for my combination.
So maybe more to come.
Anyways this gives you some idea of what kind of power the First intake manifold can make. I have basically just cleaned up the First intake manifold by making the inlet ports and the ports at the head the same in cross sectional area. By the way port number one on the intake manifold flowed 301cfm and it is one of the worse in CSA.
This is through an A4 transmission and a Yank SS3600 stall with 3.70 gears. The best chasis dyno pull was 355rwhp at 5100rpm and 377rwtq around the 4700rpm mark. Torque converter was unlocked.
Using the 20% drivetrain loss that works out to around 440 horsepower at the motor and 470 ft/lb torque. I'm in the process of changing out the valve springs and going to a larger cam. I have been told by the "experts" that my cam is to small and the valve springs to weak for my combination.
So maybe more to come.
Anyways this gives you some idea of what kind of power the First intake manifold can make. I have basically just cleaned up the First intake manifold by making the inlet ports and the ports at the head the same in cross sectional area. By the way port number one on the intake manifold flowed 301cfm and it is one of the worse in CSA.
Thread Starter
Racer
Joined: Oct 2001
Posts: 311
Likes: 2
From: Roseburg OR
Manifold measurements
Quoting BADSS from this post http://forums.corvetteforum.com/show...1868398&page=3
"The actual straight line/shortest path measurements for the FIRST is 13.5” total intake runner length. Use that and 1.76 on the diameter with a 95% efficiency on the EA program for the FIRST (out of the box). Play around with the diameter to see how much your engine could take. It'll port out to 1.87" fairly easy,, 1.92 with effort (and at 1.9+” should up the efficiency to 100%). "
"The actual straight line/shortest path measurements for the FIRST is 13.5” total intake runner length. Use that and 1.76 on the diameter with a 95% efficiency on the EA program for the FIRST (out of the box). Play around with the diameter to see how much your engine could take. It'll port out to 1.87" fairly easy,, 1.92 with effort (and at 1.9+” should up the efficiency to 100%). "
Racer
Joined: Oct 2007
Posts: 478
Likes: 1
Mine are at 1.85" at the runner. Then tapers down to the head entrance. When I was doing some measuring it looks like it would be no problem to start out at 2.00" at the runner entrance. That works out to a 3.14" CSA.
Melting Slicks
Joined: May 2000
Posts: 2,029
Likes: 63
Got mine from customs today. Looks great
I ordered mine painted silver. This way it will not stain like cast aluminum usually does and is easy to keep clean. I also ordered it with functional EGR, 2 sets of gaskets and MAP bracket. I will initially install the MAP at stock location but if they realize at annual inspection I am running without EGR I need to move the MAP to some other location and install EGR to its place.
I ordered mine painted silver. This way it will not stain like cast aluminum usually does and is easy to keep clean. I also ordered it with functional EGR, 2 sets of gaskets and MAP bracket. I will initially install the MAP at stock location but if they realize at annual inspection I am running without EGR I need to move the MAP to some other location and install EGR to its place.
Le Mans Master
Joined: Dec 2002
Posts: 5,270
Likes: 3
From: Seattle Area WA
Some tidbits of information. I'm using the First intake manifold, SLP runners and the factory TPI plenum. The motor is 355 cubic inches with the Comp Cams XFI268 cam. Dart 200cc Pro One heads and 10.72:1 compression.
This is through an A4 transmission and a Yank SS3600 stall with 3.70 gears. The best chasis dyno pull was 355rwhp at 5100rpm and 377rwtq around the 4700rpm mark. Torque converter was unlocked.
Using the 20% drivetrain loss that works out to around 440 horsepower at the motor and 470 ft/lb torque. I'm in the process of changing out the valve springs and going to a larger cam. I have been told by the "experts" that my cam is to small and the valve springs to weak for my combination.
So maybe more to come.
Anyways this gives you some idea of what kind of power the First intake manifold can make. I have basically just cleaned up the First intake manifold by making the inlet ports and the ports at the head the same in cross sectional area. By the way port number one on the intake manifold flowed 301cfm and it is one of the worse in CSA.
This is through an A4 transmission and a Yank SS3600 stall with 3.70 gears. The best chasis dyno pull was 355rwhp at 5100rpm and 377rwtq around the 4700rpm mark. Torque converter was unlocked.
Using the 20% drivetrain loss that works out to around 440 horsepower at the motor and 470 ft/lb torque. I'm in the process of changing out the valve springs and going to a larger cam. I have been told by the "experts" that my cam is to small and the valve springs to weak for my combination.
So maybe more to come.
Anyways this gives you some idea of what kind of power the First intake manifold can make. I have basically just cleaned up the First intake manifold by making the inlet ports and the ports at the head the same in cross sectional area. By the way port number one on the intake manifold flowed 301cfm and it is one of the worse in CSA.
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Pro
Joined: Feb 2005
Posts: 658
Likes: 1
From: Centerville OH
I took the FIRST apart tonight to start taking measurements.
The diameter of the base at the runner interface is 1.875 on the smallest passage and ranges up to 1.891. The runner diameter is 1.744 up to 1.751 with plenty of meat for porting. The diameter of the gasket opening is 1.899 for both the base and plenum gaskets.
I'll get runner and base passage lengths tomorrow. Also, I brought home some graduated cylinders from work so I can get an accurate plenum volume measurement.
The diameter of the base at the runner interface is 1.875 on the smallest passage and ranges up to 1.891. The runner diameter is 1.744 up to 1.751 with plenty of meat for porting. The diameter of the gasket opening is 1.899 for both the base and plenum gaskets.
I'll get runner and base passage lengths tomorrow. Also, I brought home some graduated cylinders from work so I can get an accurate plenum volume measurement.
Le Mans Master
Joined: Dec 2002
Posts: 5,270
Likes: 3
From: Seattle Area WA
Sweet. I take it you plan on porting it? I'd love to see some before/after dyno graphs if you do.
As for the graduated cylinders, nice work. I did that when I cc'd my heads/pistons (ok that was a syringe) and what not.
As for the graduated cylinders, nice work. I did that when I cc'd my heads/pistons (ok that was a syringe) and what not.
Pro
Joined: Feb 2005
Posts: 658
Likes: 1
From: Centerville OH
Here are the runner and base passage lengths for the FIRST. These were obtained with the "string and ruler" method. I measured the lengths along the top and bottom of the passage and averaged them.
Runner:
Top length -- 10.5"
Bottom length -- 6"
Average -- 8.25"
Base:
Top length -- 8.25"
Bottom length -- 7"
Average -- 7.625"
Total passage length: 8.25 + 7.625 = 15.875 inches from plenum to head
I'm taping off the plenum now to get a volume measurement. I'll post that up later.
EDIT: The plenum volume for the FIRST intake is 2935 cc (179 cu in). My original '89 TPI ported plenum measured 2220 cc (135.5 cu in). I also measured the lengths of my ACCEL base and AS&M runners. The runners are 9 11/16" and the base length is 7" for a total of 16 11/16".
Runner:
Top length -- 10.5"
Bottom length -- 6"
Average -- 8.25"
Base:
Top length -- 8.25"
Bottom length -- 7"
Average -- 7.625"
Total passage length: 8.25 + 7.625 = 15.875 inches from plenum to head
I'm taping off the plenum now to get a volume measurement. I'll post that up later.
EDIT: The plenum volume for the FIRST intake is 2935 cc (179 cu in). My original '89 TPI ported plenum measured 2220 cc (135.5 cu in). I also measured the lengths of my ACCEL base and AS&M runners. The runners are 9 11/16" and the base length is 7" for a total of 16 11/16".
Last edited by Z51L9889; Jan 26, 2008 at 05:33 PM. Reason: Added plenum volume measurements
Pro
Joined: Feb 2005
Posts: 658
Likes: 1
From: Centerville OH
I need to finish the measurements, but I've plugged some edjumacated guesses into Engine Analyzer Pro 3.3 and the porting appears to be worth about 40-50 HP/TQ on the 383 combo I'm building.
FYI -- Ported combo numbers are coming out at 545 TQ at 4000, 521 HP at 6000.
Team Owner
Joined: Sep 2003
Posts: 88,393
Likes: 2
From: eville in
Yeah, I'm going to try and port the runners to 1.9". There is plenty of meat to port them that big but the issue will be getting the tools into the runner enough to get a good shape. Also, I'm going to open up the manifold face to match my AFR 195's and blend it back to the 1.9 diameter.
I need to finish the measurements, but I've plugged some edjumacated guesses into Engine Analyzer Pro 3.3 and the porting appears to be worth about 40-50 HP/TQ on the 383 combo I'm building.
FYI -- Ported combo numbers are coming out at 545 TQ at 4000, 521 HP at 6000.
I need to finish the measurements, but I've plugged some edjumacated guesses into Engine Analyzer Pro 3.3 and the porting appears to be worth about 40-50 HP/TQ on the 383 combo I'm building.
FYI -- Ported combo numbers are coming out at 545 TQ at 4000, 521 HP at 6000.
Race Director
Joined: May 2003
Posts: 10,749
Likes: 41
Yeah, I'm going to try and port the runners to 1.9". There is plenty of meat to port them that big but the issue will be getting the tools into the runner enough to get a good shape. Also, I'm going to open up the manifold face to match my AFR 195's and blend it back to the 1.9 diameter.
I need to finish the measurements, but I've plugged some edjumacated guesses into Engine Analyzer Pro 3.3 and the porting appears to be worth about 40-50 HP/TQ on the 383 combo I'm building.
FYI -- Ported combo numbers are coming out at 545 TQ at 4000, 521 HP at 6000.
I need to finish the measurements, but I've plugged some edjumacated guesses into Engine Analyzer Pro 3.3 and the porting appears to be worth about 40-50 HP/TQ on the 383 combo I'm building.
FYI -- Ported combo numbers are coming out at 545 TQ at 4000, 521 HP at 6000.
Last edited by 88BlackZ-51; Jan 26, 2008 at 01:37 PM.
Pro
Joined: Feb 2005
Posts: 658
Likes: 1
From: Centerville OH
Yeah, me too!! 
I've input the engine details with as much accuracy as possible, and I've been measuring everything I can measure to try and get the model accurate. The one thing I still need to get is an estimate of header primary tube length.
I modeled my old combo for which I had dyno data and I was able to match it within 2-3 HP at every point along the curve, so I think I'm at least in the ballpark.
I have to admit I'm a bit surprised by the 6K HP peak. I would have expected the peak to be no more than 5500, but I'm definitely not going to complain if the model is correct.
I've input the engine details with as much accuracy as possible, and I've been measuring everything I can measure to try and get the model accurate. The one thing I still need to get is an estimate of header primary tube length.
I modeled my old combo for which I had dyno data and I was able to match it within 2-3 HP at every point along the curve, so I think I'm at least in the ballpark.
I have to admit I'm a bit surprised by the 6K HP peak. I would have expected the peak to be no more than 5500, but I'm definitely not going to complain if the model is correct.
Le Mans Master
Joined: Dec 2002
Posts: 5,270
Likes: 3
From: Seattle Area WA
Wow, your luck with EA has been better than mine. Mind you I have an old version. But I just could not get it to model my results accurately. Keep us updated!
Which cam are you running with that simulation?
Which cam are you running with that simulation?
Pro
Joined: Feb 2005
Posts: 658
Likes: 1
From: Centerville OH
I think the predicted numbers are higher than most people might expect because I have put a LOT of time and effort into defining exactly what I want my engine to do (and NOT do) and I have selected the parts specifically to meet those goals. I could have built an engine with one of the "popular" cam/intake combos and been very happy, I'm sure, but when I looked carefully at those combinations they did not provide me with the best power and torque characteristics for the way I use the car.
There have been several cars on the forum over the years that seem to make more power than most people think they should. The owners' always seem to get asked "What's your secret?". IMHO, the secret is that those guys went through the same thought process that I am using now, and then spent the time (and money) to optimize the tune once the car was running.
Pro
Joined: Feb 2005
Posts: 658
Likes: 1
From: Centerville OH
Duration @ .050: 230/242
Lift w/ 1.6 rockers: 0.602/0.586
LSA: 111.5
I have spent a bunch of time over the last year playing with EA to get accurate results. The trick is to get as much real data on the parts as you can, particularly for a TPI style intake and for the cam lobe shape. I also had the advantage of having chassis dyno data for my car so I could keep tweaking the sim until I got the curve shape just right.
Last edited by Z51L9889; Jan 26, 2008 at 06:26 PM.
Pro
Joined: Feb 2005
Posts: 560
Likes: 0
From: Hamilton New Jersey
Some tidbits of information. I'm using the First intake manifold, SLP runners and the factory TPI plenum. The motor is 355 cubic inches with the Comp Cams XFI268 cam. Dart 200cc Pro One heads and 10.72:1 compression.
This is through an A4 transmission and a Yank SS3600 stall with 3.70 gears. The best chasis dyno pull was 355rwhp at 5100rpm and 377rwtq around the 4700rpm mark. Torque converter was unlocked.
Using the 20% drivetrain loss that works out to around 440 horsepower at the motor and 470 ft/lb torque. I'm in the process of changing out the valve springs and going to a larger cam. I have been told by the "experts" that my cam is to small and the valve springs to weak for my combination.
So maybe more to come.
Anyways this gives you some idea of what kind of power the First intake manifold can make. I have basically just cleaned up the First intake manifold by making the inlet ports and the ports at the head the same in cross sectional area. By the way port number one on the intake manifold flowed 301cfm and it is one of the worse in CSA.
This is through an A4 transmission and a Yank SS3600 stall with 3.70 gears. The best chasis dyno pull was 355rwhp at 5100rpm and 377rwtq around the 4700rpm mark. Torque converter was unlocked.
Using the 20% drivetrain loss that works out to around 440 horsepower at the motor and 470 ft/lb torque. I'm in the process of changing out the valve springs and going to a larger cam. I have been told by the "experts" that my cam is to small and the valve springs to weak for my combination.
So maybe more to come.
Anyways this gives you some idea of what kind of power the First intake manifold can make. I have basically just cleaned up the First intake manifold by making the inlet ports and the ports at the head the same in cross sectional area. By the way port number one on the intake manifold flowed 301cfm and it is one of the worse in CSA.