Looking for Opinions on a Class Time Attack Build
Thread Starter
Joined: Aug 2003
Posts: 4,047
Likes: 3
From: NYC/T.O.
Looking for Opinions on a Class Time Attack Build
I know some choices will be suboptimal but just looking for predicted power figures.
86 Sport
S4 13B-DEI Motor, Bridgeported (Or Half Bridge Or Streetport, whichever makes the most power with the following restricted mods)
Motec ECU
Stock Intake Manifold
Stock Throttle Body
Cold Air Intake
Short Primary Collected Headers
100 Cell High Flow Cat
2.5" to 3" Catback Exhaust
Non-Power
5.12 Final Drive
Close Ratio Trans
Coilovers
Poly Bushings and Mounts
ACT Prolite Flywheel
ACT 4 Puck Sprung Clutch
Anyone have a well-educated guess for whp and torque numbers?
Also, same question and same mods, but 90 GXL with Bridgeported S5 13B-VDEI Block
86 Sport
S4 13B-DEI Motor, Bridgeported (Or Half Bridge Or Streetport, whichever makes the most power with the following restricted mods)
Motec ECU
Stock Intake Manifold
Stock Throttle Body
Cold Air Intake
Short Primary Collected Headers
100 Cell High Flow Cat
2.5" to 3" Catback Exhaust
Non-Power
5.12 Final Drive
Close Ratio Trans
Coilovers
Poly Bushings and Mounts
ACT Prolite Flywheel
ACT 4 Puck Sprung Clutch
Anyone have a well-educated guess for whp and torque numbers?
Also, same question and same mods, but 90 GXL with Bridgeported S5 13B-VDEI Block
Last edited by Roen; May 30, 2017 at 09:19 PM.
Rotary Enthusiast
Joined: Jan 2005
Posts: 846
Likes: 14
From: hsv al
What time attack is this for? Do you have a link to the rules?
Standard people's power:
S4 motor: 150 not ported, 170 street, 190 bridged.
S5 bridged: maybe a tad over 200.
You have to get rid of the exhaust "diffuser" in the exhaust sleeves.
"Race engines" :
The SCCA "IT" S5 Rx7s make around 190 with no porting and stock intake. Banzai Racing has it on their Dyno section here:
Banzai Racing (Keefer 13B RX-7 Engine Installation)
The SCCA E prod 13B from Mazdatrix makes around 230 HP.
That's a street ported motor, where the intersection of the corner and side seal can not be seen when looking into the intake ports.
it would also have new engine parts, ceramic seals, exhaust porting, lightened rotors, WPC coatings, etc... all on a "dual Y" manifold with a IDA carb and 42mm chokes.
Standard people's power:
S4 motor: 150 not ported, 170 street, 190 bridged.
S5 bridged: maybe a tad over 200.
You have to get rid of the exhaust "diffuser" in the exhaust sleeves.
"Race engines" :
The SCCA "IT" S5 Rx7s make around 190 with no porting and stock intake. Banzai Racing has it on their Dyno section here:
Banzai Racing (Keefer 13B RX-7 Engine Installation)
The SCCA E prod 13B from Mazdatrix makes around 230 HP.
That's a street ported motor, where the intersection of the corner and side seal can not be seen when looking into the intake ports.
it would also have new engine parts, ceramic seals, exhaust porting, lightened rotors, WPC coatings, etc... all on a "dual Y" manifold with a IDA carb and 42mm chokes.
Thread Starter
Joined: Aug 2003
Posts: 4,047
Likes: 3
From: NYC/T.O.
What time attack is this for? Do you have a link to the rules?
Standard people's power:
S4 motor: 150 not ported, 170 street, 190 bridged.
S5 bridged: maybe a tad over 200.
You have to get rid of the exhaust "diffuser" in the exhaust sleeves.
"Race engines" :
The SCCA "IT" S5 Rx7s make around 190 with no porting and stock intake. Banzai Racing has it on their Dyno section here:
Banzai Racing (Keefer 13B RX-7 Engine Installation)
The SCCA E prod 13B from Mazdatrix makes around 230 HP.
That's a street ported motor, where the intersection of the corner and side seal can not be seen when looking into the intake ports.
it would also have new engine parts, ceramic seals, exhaust porting, lightened rotors, WPC coatings, etc... all on a "dual Y" manifold with a IDA carb and 42mm chokes.
Standard people's power:
S4 motor: 150 not ported, 170 street, 190 bridged.
S5 bridged: maybe a tad over 200.
You have to get rid of the exhaust "diffuser" in the exhaust sleeves.
"Race engines" :
The SCCA "IT" S5 Rx7s make around 190 with no porting and stock intake. Banzai Racing has it on their Dyno section here:
Banzai Racing (Keefer 13B RX-7 Engine Installation)
The SCCA E prod 13B from Mazdatrix makes around 230 HP.
That's a street ported motor, where the intersection of the corner and side seal can not be seen when looking into the intake ports.
it would also have new engine parts, ceramic seals, exhaust porting, lightened rotors, WPC coatings, etc... all on a "dual Y" manifold with a IDA carb and 42mm chokes.
Rules - Ontario Time Attack
I want to avoid getting 12 Engine PIPs and being forced to Dyno class, basically I want to exploit PIPs as much as I can.
Porting is 7 PIPs
Standalone + Tune + Fuel is 2 PIPs
The other 2 can be spent on the following mods:
Header: 2 PIPs
Intake Manifold + Throttle Body: 1 PIPs
Pre-silencer / Straight Pipe: 1 PIPs
High Flow Cat: Free
5.0F.4 - Porting is 7 points.
Includes apex seal change (and assuming balancing/clearancing/oiling).
So many points.
-------
5.0D.9 - Adding a Super Charger to Normally Aspirated car is 9 points.
Includes 5.0A.1 - intake manifold/tb/air intake sensor sysem (AFM) if Roots style S.C.
Includes 5.0C.2 - engine management using stock sensors/components
Includes 5.0D.5 - pulley system
If race gas is points free (I didn't see that mentioned) then you don't need the intercooler (points), so you can use the remaining 2 points for exhaust.
5.0B.1 - Non-turbo cars engine to cat pipes 2 points
4.8.1.11 - High Flow Cat 0 points
4.8.1.15 - Cat Back 0 points
They do not limit the size of the supercharger so if you run a really big one you can run high boost and make some power, but you are limited by the stock fuel system.
That is 5.0C.3 - modification to the fuel pump, regulator, injectors 1 point.
Limits you to ~250rwhp, but much more power "under the curve" than porting.
Includes apex seal change (and assuming balancing/clearancing/oiling).
So many points.
-------
5.0D.9 - Adding a Super Charger to Normally Aspirated car is 9 points.
Includes 5.0A.1 - intake manifold/tb/air intake sensor sysem (AFM) if Roots style S.C.
Includes 5.0C.2 - engine management using stock sensors/components
Includes 5.0D.5 - pulley system
If race gas is points free (I didn't see that mentioned) then you don't need the intercooler (points), so you can use the remaining 2 points for exhaust.
5.0B.1 - Non-turbo cars engine to cat pipes 2 points
4.8.1.11 - High Flow Cat 0 points
4.8.1.15 - Cat Back 0 points
They do not limit the size of the supercharger so if you run a really big one you can run high boost and make some power, but you are limited by the stock fuel system.
That is 5.0C.3 - modification to the fuel pump, regulator, injectors 1 point.
Limits you to ~250rwhp, but much more power "under the curve" than porting.
Thread Starter
Joined: Aug 2003
Posts: 4,047
Likes: 3
From: NYC/T.O.
5.0F.4 - Porting is 7 points.
Includes apex seal change (and assuming balancing/clearancing/oiling).
So many points.
-------
5.0D.9 - Adding a Super Charger to Normally Aspirated car is 9 points.
Includes 5.0A.1 - intake manifold/tb/air intake sensor sysem (AFM) if Roots style S.C.
Includes 5.0C.2 - engine management using stock sensors/components
Includes 5.0D.5 - pulley system
If race gas is points free (I didn't see that mentioned) then you don't need the intercooler (points), so you can use the remaining 2 points for exhaust.
5.0B.1 - Non-turbo cars engine to cat pipes 2 points
4.8.1.11 - High Flow Cat 0 points
4.8.1.15 - Cat Back 0 points
They do not limit the size of the supercharger so if you run a really big one you can run high boost and make some power, but you are limited by the stock fuel system.
That is 5.0C.3 - modification to the fuel pump, regulator, injectors 1 point.
Limits you to ~250rwhp, but much more power "under the curve" than porting.
Includes apex seal change (and assuming balancing/clearancing/oiling).
So many points.
-------
5.0D.9 - Adding a Super Charger to Normally Aspirated car is 9 points.
Includes 5.0A.1 - intake manifold/tb/air intake sensor sysem (AFM) if Roots style S.C.
Includes 5.0C.2 - engine management using stock sensors/components
Includes 5.0D.5 - pulley system
If race gas is points free (I didn't see that mentioned) then you don't need the intercooler (points), so you can use the remaining 2 points for exhaust.
5.0B.1 - Non-turbo cars engine to cat pipes 2 points
4.8.1.11 - High Flow Cat 0 points
4.8.1.15 - Cat Back 0 points
They do not limit the size of the supercharger so if you run a really big one you can run high boost and make some power, but you are limited by the stock fuel system.
That is 5.0C.3 - modification to the fuel pump, regulator, injectors 1 point.
Limits you to ~250rwhp, but much more power "under the curve" than porting.
But thanks for this!
Why would this limit me to 250 rwhp? Supercharger?
Last edited by Roen; Jun 26, 2017 at 01:10 PM.
Limited to ~250rwhp because 11 points doesn't get you any modifications to the fuel system so you are limited by stock injector flow rate and stock fuel pressure regulator pressure.
That is that 12th point (5.0C.3)as I pointed out above.
This is easy to cheat of course.
For instance, it is not your fault if the fuel return hardline has been hit by a rock or pinched by a jack before you bought the car in a section that it runs under the rear subframe that you never noticed.
That would get you more fuel pressure for more flow through the injectors.
Or you can do the "legal cheating".
You could do it legally with the "Blue Printing" process. Get 100 FC fuel pressure regulators and find the one that has the (slightly) highest pressure. Get 400 FC fuel injectors and find the ones that have the (slightly) higher flow rates.
That is that 12th point (5.0C.3)as I pointed out above.
This is easy to cheat of course.
For instance, it is not your fault if the fuel return hardline has been hit by a rock or pinched by a jack before you bought the car in a section that it runs under the rear subframe that you never noticed.
That would get you more fuel pressure for more flow through the injectors.
Or you can do the "legal cheating".
You could do it legally with the "Blue Printing" process. Get 100 FC fuel pressure regulators and find the one that has the (slightly) highest pressure. Get 400 FC fuel injectors and find the ones that have the (slightly) higher flow rates.