I have a 23A10SS FBO E85, Ported MSD, Heads Cam with a OEM 95mm TB. Will I see any decent gains moving to a NW 103mm or is it better to just keep the 95mm on there? I havent seen many comparisons for the 95 vs 103.
I have a 23A10SS FBO E85, Ported MSD, Heads Cam with a OEM 95mm TB. Will I see any decent gains moving to a NW 103mm or is it better to just keep the 95mm on there? I havent seen many comparisons for the 95 vs 103.
Last edited by Saberscar223; 04-21-2025 at 11:40 AM.
It all comes down to if the vehicle needs it or not, and how it is installed.
The 103 wont fit on a factory intake manifold or the common LT2 intake manifold most of the 6th Gen guys run without the throttle body adapter plate as well. Only the aftermarket intake manifolds (Holley, MSD, BTR, etc) have the correct inlet to truly utilize a 103. Using the adapter plate will still pick up some power, but not as much as if you didnt have the adapter plate necking down the inlet. Also, depending on the cam and the rest of the components, the throttle body may not actually be needed.
Will it gain? Yes. In almost every scenario.
Will it gain enough to make sense in dollars per hp gained? That depends on your set up.
IMHO No.
These do good with E85. Spend the money there.
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My bad I forgot to mention I am on full E right now.Originally Posted by Alvin
What heads and cam? In the MSD ported? I?ve looked a lot into this too, but for a bolt on car and couldn?t find any direct comparisons except one video on YouTube, but it was a ported 95 vs 103.
A ported 95mm TB is plenty for your setup. We usually go with the Solar ported 95mmTB (100mm Effective) for this. I actually have one with less than 500 miles on it for sale for $250. Had to tell if you would see any gains, but if you did it would be past 6000 rpm.
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Its a GPI Ported MSD
What is the drivability difference between a 95, ported 95 like the soler vs a 103?
none
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Check your MAP at WOT, compare to Baro to see if you have a significant inlet restriction. Even then, I don't believe that the last few HP from a larger/ported non-stock TB is worth the headaches that come with them in terms of torque control.
I don't believe that the last few HP from a larger/ported non-stock TB is worth the headaches that come with them in terms of torque control.[/QUOTE] -
is this what you mean by torque control headaches?
Specific Torque Control Challenges
Part-Throttle Drivability:
A 103mm TB increases airflow at low throttle angles, causing excessive torque for small pedal inputs. This leads to jerky or ?twitchy? behavior, especially in low gears or traffic.
Tuning Headache: Adjust Electronic Throttle Control (ETC) maps (e.g., Desired Throttle Area vs. Pedal Position in HP Tuners) to reduce throttle sensitivity. This requires extensive logging of throttle position, MAF airflow, and torque output.
Transient Airflow Spikes:
Rapid throttle changes (e.g., during manual shifts or track throttle blips) create larger airflow transients with a 103mm TB, challenging the ECU?s ability to maintain accurate dynamic airflow.
The below dyno runs are my car. Normally Aspirated 416 stroker, ported MSD intake, full length headers, AFE CAI, etc, etc. 2019 Corvette.
The NW 103 was worth 10hp. Basically a lot of money on a per hp basis. FWIW
Crank pressure testing new 416 TB Annotated.jpg
One of the few comparisons I've seen, thanks.
I want to make sure I'm fully understanding this. Was this a stock or ported 87mm? I'm assuming the car had ported heads and cam?
Was this done on the same day? If so it might be less even than that.
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102mm and up don't make any power on anything except big inch strokers and blower motors, period.
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Stock 87mm, no porting. It's the original throttle body that came with the car and I ordered the car new.
FED cylinder head castings. I replaced the Manley SS valves with LT4 titanium intake valves and LT1/4 exhaust valves. I also used different retainers and springs vs what FED uses.
Decent size cam for a N/A engine. Goal was mid-range torque since this is a track day/time trial car. Cam specs are attached.
Cam CArd Screen Shot Screenshot 2025-06-24 140914.jpg
Same day, same dyno, tuned in each case. Maybe 90 minutes apart.
I was testing my theory that by moving the 103mm intake opening forward a couple inches....which is essentially what the 103mm throttle body does....any changes in power would be minimal. The CAI I have (AFE) is sized to fit the 87mm throttle body.
---- CAI for 87mm throttle body (tb)
----103mm (tb)
----103mm MSD intake opening
It would be interesting to see if a larger CAI tube had any impact but I didn't have one to test.
I did some follow-up checks with the 87mm on the street and looking at WOT vs MAP, I'm not seeing any significant restriction. MAP is showing .98 Bar at >6000 rpm.
Like many things, there's a balance of needing every single 1/10th of a horsepower and then there's just wanting something solid and reliable. I chose the latter
We did a bunch of testing 15 years ago on multiple platforms both NA and forced induction 102mm versus the stock 90s back then. On both an engine dyno and chassis dyno. We found there was zero gains most of the time on any NA engine under roughly 416-418 with really good heads, intake, cam. Radical 427s and bigger gain a little chunk. Anything radical like my buddy's old bracket car with 430 inch, high RPM valve train, Holley high ram that's the kind of NA setup they make power on.
The GM PD blower cars will all pick up power but they require additional work you can't just bolt on the bigger T-body. But anything under 400 inches with mild H/C/I gained absolutely nothing.
Another thing I found all by myself and I've showed countless people now, any bend in the airflow in front of the throttle body costs HP and a good chunk most of the time. Take your average 5th gen Camaro for instance. Run it with the stock configuration air intake and then take that off and put a straight piece of tubing with a bellmouth on it on the car and watch what you pick up.
The GEN5 DI motors are significantly more efficient and pump a considerably more amount of air than the port injected motors, but the results are still pretty close to the same. You need to be pumping a shit load of air through an NA motor to benefit from the bigger T-body. That just typically is not your bottleneck.
Last edited by edcmat-l1; 17 Hours Ago at 03:10 PM.
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That's interesting because I'm seeing those packages (big n/a) skipping the 103 and going straight to the 112.
Is there a place for the 103?
Last edited by big_sapper; 16 Hours Ago at 03:18 PM.
2023 Camaro 2SS (A10)
There's very little if any gain on bigger power supercharged engines going from 102/3 to 112. I'd bet there's zero gain on any NA motor going from 102/3 to 112. Even big inch radical setups, solid roller, 8000 rpm, etc.
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