Big Bore Throttle Body (BBTB) Comparison - Stock vs. Dinan vs. Riot Racing w/ Pics!!

[BimmaDave]

Disclaimer: This Thread is based off of my observations, experience, and logic only, so PLEASE do not comment or post if you disagree with any of them. You have the right to think whatever you want... just please don't clog my thread with forum BS. This is an account of my experience, and I have no interest in arguing with ANYONE about any different ideas, experience, or theories that you may or may not have. I also in no way intend to promote or bash BMW, DINAN, or Riot Racing. I'm simply showing their products as they are and explaining my personal experience with them.


OK Guys-

I was looking for something new for my e36 (since I'm addicted to modding it ) and spent some time looking for a thread about BBTB's and the differences between the options that are available. What I wanted was some reviews from people who had personal experience with them, and a rundown about their real-world performance - so I could determine if it was something I would be interested in, and further, if it was "worth it". I was particularly looking at comparisons between BBTB's, since I already have a Dinan BBTB and thought about upgrading to Riot Racing's BBTB.

I was less than satisfied with what I found (on bimmerforums or ANY other forum for that matter)... mostly people flaming, being flamed, or arguing about theoretical nonsense and whether or not it "does anything".

So I decided to make this thread for any serious E36 owners who want a new mod and aren't sure about the BBTB... since I own and have used all 3.


The logic behind the Big-Bore Throttle Body:

The E36 Throttle body is a modest 63.83mm (internal) bore from the factory, while the intake manifold has a 70mm opening that it mates up to. This means that the TB is not set up to flow as much air as it could...which inspired companies like Dinan, Riot Racing, and VAC Motorsports to develop a bored out throttle body which would allow more air to pass through the throttle body at WOT, thus reducing the resistance and increasing throttle response and peak horsepower.

Since the engine is essentially a big air pump, as we know, increasing the flow of air and reducing resistance in the intake tract will usually increase our overall horsepower. This is why mods like the M50 manifold, Samco intake boot, ASC Throttle body delete, 3.5" HFM, and Cold Air Intakes are commonly seen on e36's in an effort to squeeze out every last bit of power from our S52's. It can be broken down simply... Larger tubing, larger intake runners, smoother curves = less resistance, more power.

It just makes sense to me that there would be an increase in power from adding a BBTB, since the whole idea of most of the NA Mods is to lower the restriction of the 3" intake system. I've heard many people argue that the 3.5" intake setup is totally unnecessary for an NA M3. I've also heard that the TB is "not the bottleneck". However, If you believe that the 3.5" HFM, 3.5" CAI, or samco boot does anything, then you have to believe that this will too because it operates off of the exact same principle. The 3.5" Intake is 88.9mm inner diameter (3.5"), which smoothly shrinks down to 76.2mm (3") in the Bimmerworld boot, then goes through a throttle body which has a 63.83mm (2.51") inner diameter? Sounds like a bottleneck to me... Even at 68mm, the TB is still the smallest inner diameter in the intake tract!

Note: Dinan, Jim Conforti, and Active Autowerke all must believe that the 3.5" HFM makes a difference... since they all make a tune specifically for it AND recognize the power gains it yields.

The last thing to consider is throttle response. The idea here is that being a larger bore, at the same throttle position the BBTB will pass more air. This means that when you're at 25% throttle, the different throttle bodies will each pass different amounts of air and cause the engine to accelerate more or less. This GREATLY effects the way the throttle feels in the e36, there is no 2 ways about it. The BBTB pulls your neck harder when you hit the gas and makes the car seem to accelerate much more effortlessly at low-mid throttle. Throttle response is mostly based on feeling, though, so this cannot really be described. Drive an e36 with a BBTB and you will understand.


So, back to the point. I started with the OEM throttle body (like the rest of you), upgraded to the Dinan BBTB (because I got it for free from a friend who totaled his e36) and I loved it. I also have Dinan stage V software, which apparently is designed to work with their BBTB (although you do not need software to run either the Dinan or Riot Racing BBTB). Last week, I upgraded to the Riot Racing BBTB, and WOW... I cannot describe my level of satisfaction. It blows the Dinan BBTB away and in my opinion, is worth every penny. But I'll get to that later. So, I have owned all 3 and used all 3 personally on my car.


Now for the comparison:

Here are a couple of pictures of the TB's next to each other.





Now I'll separate them. It will be Description first, then pictures.

Stock TB:

Inner Diameter = 63.83mm
Throttle Arm: Double Sided

THINGS TO NOTICE: The OEM throttle body has an uneven bore... wider in the center than in the rest. This is restrictive and is not smooth.

Pictures of the Stock throttle body:


Dinan BBTB:

Inner Diameter = 66mm
Throttle Arm: Double Sided (OEM Style)
Area compared to Stock: + 6.46%
Price: $300 + $350 Core Deposit (ouch) + Tax + Shipping

THINGS TO NOTICE:

The Dinan throttle body appears to have been bored at a strange angle... if you look you can see that only one side of the inside of the TB appears to not have been changed at all.

The Dinan throttle body (on the manifold side) has a very thin inner wall... much thinner than any of the outer edges of the RIOT or OEM TB's. This has to do with the angle that it was bored at. It's uneven and looks very close to the breaking point of the walls of the TB, but has held up just fine.

Pictures of the Dinan Big-Bore Throttle Body:



Riot Racing BBTB:

Inner Diameter = 68mm
Throttle Arm: Single Sided
Area compared to Stock: +11.90% (+ X% because of low profile throttle plate and Single Sided throttle arm)
Cost: $250 + $100 Core Deposit (About $287 when it's all said and done if you live in CA. If you don't, lucky you, it's about $267)

THINGS TO NOTICE: This is the only throttle body with a smooth path all the way through. Notice that this TB was bored straight and that there is only 1 inner diameter that is held consistently.

Also, notice that there is a single sided throttle arm.

Pictures of the Riot Racing Big-Bore Throttle Body:




What the Inside looks like: Smoothness + Single/Dual Throttle Arm design

The OEM and DINAN throttle bodies have double-sided throttle arms, and the RIOT RACING unit has a single throttle arm. This alone frees up quite a bit of area. Also the entire inner diameter is consistent on the Riot Racing TB, unlike the OEM and DINAN TB's. See these pictures if you don't know what I mean:



And Lastly, The Big Question: POWER

I've been getting lots of people asking for dyno results. Well, I didn't dyno my car before/after and I've already gotten rid of my Dinan BBTB... so I apologize for anyone interested purely in power. There's NO question that the BBTB will add horsepower vs the stock one, and by the same principle, the Riot Racing one will beat out Dinan's. However, by how much I'm not sure. However, one thing I can say for sure is that the Riot Racing BBTB Feels much more refined than Dinan's and that it has absolutely no problems or downsides that I can find (plus, it's cheaper!).

However, for those of you interested in power numbers, Here's a few dyno charts that show the stock bbtb vs riot racing back to back.

Westcoastriots Dyno:

This dyno chart is from westcoastriots.com which I believe to be accurate, but some people speculate that it may be biased (since they sell the throttle body). This is NOT the only example. Their dyno page can be found here: http://www.westcoastriots.com/htmlfiles/dynopage.htm



Eurotuner's Project Car Dyno:

This chart is from eurotuner's article which includes Riot Racing's BBTB. They did back to back dyno runs (with detailed methodology in the article) and found the BBTB to add 5.4 WHP. It's safe to assume that they had no reason to lie or fake their dyno results page.

Here's a quote from their article which can be found Here: http://www.eurotuner.com/techarticle...g/viewall.html

This is a quote from the article:

"Next was the $200 big-bore throttle body from Riot Racing. With a 68mm port to perfectly match the inlet port of both the M50 and M52 intake manifolds, coupled with the thinner throttle plate, we were confident we'd see a gain.

On the dyno, the peak power went up to 236whp at 6700rpm. RR's claim of an 11% flow improvement was good for a fairly consistent 3-5hp gain from 4000rpm onwards, peaking at 5.4 at 6900rpm. We've had no adverse affects to throttle response or engine idle either."

This is their Dyno image. It's difficult to see though, because they dyno'd back to back after several mods.






OK, now a real-world review...

Stock: The TB is fine on the E36, but after doing the M50 manifold conversion, the throttle response seemed to go to hell. There's so much less torque in the 2000-4500rpm range that even daily driving, I felt like I had to constantly push the gas to 50%-75% to climb hills and accelerate without revving out (normal daily driving). Also, it doesn't make sense to have a hugely modified intake tract that bottlenecks at a 64mm opening.

Dinan: I loved this TB when I got it... it freshens up the pedal and you really notice it. It helped reverse the feeling of the loss of torque, but also made the car somewhat difficult to drive. When you BARELY touch the gas, the car seems to want to GO, then from 10-50% throttle, doesn't seem to have a linear response. Also, The idle was unstable (if I let it idle for a couple minutes, it would bog to 400rpm then back to 800 roughly every 30 seconds). Also, it made a very annoying (and embarrassing) whistle sound every time I crossed about 5% throttle (either when pushing on the gas or letting off, and would whistle for hours if I held it there). The pedal was very touchy, even after several adjustments of the throttle cable.

Riot Racing: The most impressive upgrade I have done in a while. I won't say anything about horsepower, although according to RR you're looking to get around 5-8whp out of it depending on the mods you have... and the Butt dyno Definitely agrees!! The car feels faster in the 4500-7000 range. I believe that logically, it HAS to add some power up top, since the smallest part of my intake system is now 12%+ larger than stock! But the biggest difference that the Riot Racing BBTB makes is the smoothness of it all. I felt like I lost a bit of the OEM feel of power when I did the m50 manifold, and the OEM refinement of the throttle control when I did the dinan BBTB, but with this one, I got back the OEM feeling of quality from the entire setup. It's easier to shift smoothly and can be driven gently and comfortably if you want to... but when I do hit the gas a little bit, it pulls me back in my seat WAY more than stock, and even noticeably more than the dinan BBTB, and inevitably adds a few horsepower. It's definitely a Win-Win!!

Seriously guys, I'm not a rep, I stand to gain nothing from making this thread. But this Riot Racing TB upgrade has made me so happy that I felt it necessary. I think that everyone who has an m50 manifold should buy one of these things... they REALLY make it feel better, more responsive, and faster. Also, the machining quality from Riot Racing is second to none, and their customer service is fantastic. The way my car sits now (see my sig for mod list) feels like it drives as smoothly and refined as a completely stock car. Plus, the effect of the better throttle response can be seen totally stock, m50 manifold, Cams, forced induction, etc. This thing can only help... no matter what mods you have already, or plan to do in the future. Plus, no software required!! That's a huge benefit on its own... it sometimes seems like there's never a perfect off-the-shelf tune meant for your exact setup.

Also, on a side note, Todd at westcoastriots was very helpful... he answered all my questions, and even allowed me to send in my throttle body ahead of time so I didn't have to pay the Core charge (those things always make me uncomfortable). They had it shipped incredibly fast, and from what I could see (and feel), they are obviously the best machinists who have ever tackled this job. Bravo, Riot Racing!!

PLEASE NOTE: This Thread is based off of my observations, experience, and logic only, so PLEASE do not comment or post if you disagree with any of them. You have the right to think whatever you want... just please don't clog my thread with forum BS. This is an account of my experience, and I have no interest in arguing with ANYONE about any different ideas, experience, or theories that you may or may not have. I also in no way intend to promote or bash BMW, DINAN, or Riot Racing. I'm simply showing their products as they are and explaining my personal experience with them.

Thanks for reading, I hope this helped somebody.

-Dave

[JETninja]

Very cool, getting some back to back dyno runs done would really be nice to see where the gains are.

[BimmaDave]

Very cool, getting some back to back dyno runs done would really be nice to see where the gains are.

Yeah... I understand that if the only thing that you're interested in is Horsepower, that would be great... But the problem is, the power is not even close to being the best reward for this mod.

Riotracing has dyno charts which can be found Here: http://www.westcoastriots.com/htmlfiles/dynopage.htm which shows about 4-8whp depending on the mods of the car, and eurotuner has a dyno test showing 5.4whp on their e36 linked here: http://www.eurotuner.com/techarticle...g/viewall.html

I would hate to see the MANY other factors involved with dyno testing interfere with the numbers, and have that discredit the mod. Besides, It's more of a "good-feeling" mod than a "I'm gonna win a race I would have otherwise lost" mod.

[99MPower]

Riotracing is going to post "biased" dyno sheets... we need a independent 3rd party to do back to back dyno runs on the same day, same dyno, with different TBs

[R3VOLT]

I didny realize how cheap the RR BBTB was. I wonder how long it takes them to actually machine a stock TB.. anyways interesting read. Thanks

[BimmaDave]

Riotracing is going to post "biased" dyno sheets... we need a independent 3rd party to do back to back dyno runs on the same day, same dyno, with different TBs

Thread Updated with Dyno graphs from multiple sources.

You may find it interesting that eurotuner saw a larger HP/torque increase than riotracing claim on their website.

They certainly had nothing to gain from lying or faking a dyno...

-Dave

[gk325is]

BBTB are stupid!

Nah good job with the detailed post with pics and opinion.

If you guys want a dyno comparison I would be more then happy to do the back to back with one or both. Bimmadave if you would send me one or both I will do the test on my car. Or if you want to drive to the bay I will pay for runs with your car. I want to put this BBTB thing to rest!

[scooper]

Nice post OP! I believe Treehouse and VAC make BBTBs too. Any opinions of those? I don't think they are bored out stock pieces but rather machined pieces from scratch. I'd be interested to see if either the Dinan or RiotRacing BBTBs make any more whp over stock. The logic for more hp is there, but I am somewhat skeptical unless the dimensions are much bigger. To be fair you would need to test all set-ups under the same conditions.

[NeilM]

The throttle body bore configuration is a bit more complicated than described here. You can't easily tell with the TB on the car, but if you look at a dismounted TB closely you'll see that the inlet and outlet bores are axially displaced from one another by a small amount. In fact the TB casting is designed for that, with the inlet end moved slightly toward the rear of the car.

Where the two bores meet this forms a ledge against which the throttle plate closes, sealing the intake properly when the accelerator is in the rest position. This in turn allows idle speed to be controlled properly by the ECU via the Intake Control Valve (ICV), which bleeds air directly into the manifold plenum, bypassing the TB altogether.

If you simply enlarge the TB the easy way by boring straight through it, you'll machine off that ledge and mess up the throttle plate sealing, plus risk breaching the wall in the casting.

Instead you have to bore in separately from each end, and/or at an angle. This isn't easy because there's not much casting wall thickness to work with (see the OP's pix), so the process must be fixtured and controlled quite precisely. I haven't examined a Dinan TB, but you shouldn't jump to the conclusion that their method is "a lower quality job." However it's apparent that Riot has developed an effective way to maintain the required bore offset while machining out the TB to the maximum size allowed by the stock manifold port. They've done a very nice job of it for a reasonable price.

I wouldn't suggest a BBTB unless you're also opening up the rest of the intake tract (3.5" HFM, ASC delete, etc.), but as a final step it's worth considering.

Neil
96 M3 - Riot Racing TB, a few other engine upgrades.

[boomersooner523]

Wow. Excellent post OP! I'll be getting one when the funds allow. Thanks!

[ACHTUNG!!]

I just bought a BBTB but it's a custom unit that was made by a guy in Germany. 68mm diameter. I have a S52 converted to OBD1 with 3.5" HFM, M50 intake, Schrick cams and 24lb injectors.I'm looking forward to installing it.

[Brent 930]

5hp pulls you back in your seat?

I actually don't know what the stock TB is like since I have been using Dinan ever since. Sounds like the RIOT might be worth a try. I still wonder if it will actually make a bigger difference than power pulley's which are all but worthless.

[adamnur]

Thanks for the detailed review, that helps me for sure. I have the M50 sitting in my garage but haven't put it on, partially because of the potential torque loss...I think i might get the RR BBTB at the same time as the manifold now.

Curious, have you had your car dyno'd? Looks like you've pretty much maxed out the NA intake mods and others.

[BimmaDave]

5hp pulls you back in your seat?

I actually don't know what the stock TB is like since I have been using Dinan ever since. Sounds like the RIOT might be worth a try. I still wonder if it will actually make a bigger difference than power pulley's which are all but worthless.

Well, 5hp doesn't pull you back in your seat... but the difference in airflow vs throttle position definitely makes you feel the power faster than the stock or dinan throttle bodies.

It's basically fooling you by translating a small amount of throttle in the pedal into a larger amount of acceleration than stock... But it's very nice. Like I said in the post, it's mostly for feeling. You have to feel it before you can possibly know, and trust me.. it feels good.

Thanks for the detailed review, that helps me for sure. I have the M50 sitting in my garage but haven't put it on, partially because of the potential torque loss...I think i might get the RR BBTB at the same time as the manifold now.

Curious, have you had your car dyno'd? Looks like you've pretty much maxed out the NA intake mods and others.

The torque loss with the m50 is not "potential"... it's definite. I'm a torque lover and have gone back and forth on this mod a dozen times because it feels to me like twice the loss of torque you get from turning on your A/C Compressor. Horsepower without torque is boring for me...

That's why I got the 3.91 LSD... which helps with the torqueless feeling more than anything else. But even then, After using the 3.91 with the S52, switching to the m50 is even more noticeable. That thing's a neck breaker with the stock manifold.

So, most of my mods were in an effort to restore some lost torque. The pulleys, fan delete, and software probably made the only noticeable difference to actual torque numbers in the low-mid range. But I'm not saying the BBTB actually increases torque that much... probably only about 5 lb/ft. But the extra air at any given throttle position just makes the car FEEL like it moves effortlessly - similar to the feeling I had using the s52 manifold.

After doing the M50, I always noticed that I had to push the throttle WAY more just to drive around. It went from 10% throttle to climb hills and go from 2000-4000 rpm, to 50% throttle with the m50.

Like everything else, the M50 is a trade-off. There's no question that M50 converted cars are "faster" when racing. But for DD, there's nothing like torque when you're driving in traffic and don't want to get busted for revving your engine to 7k in second gear just to pass a minivan.

And as far as getting a Dyno, No I've never gotten one... I've always been hesitant to. I like to pretend that all my mods do as much as they're supposed to, and would feel like a total douche if I found out that I had significantly less power than expected. I'd expect 230-240whp based on other peoples' results, but every car's different. I've had 4 e36's now, and this engine feels much more powerful than any of the others. Of course, it was rebuilt less than 8k miles ago (which helps), but the shop that did it didn't use OEM parts and claims that their machining process increases power... and that definitely registered on the butt dyno.

Plus, I don't want my friends to know how much whp I have LOL. I like it to stay the mysterious m3 that's "way faster than it should be..." which usually holds true when I'm racing non-BMW cars that are rated at much higher horsepower numbers, and even power/weight ratios, and I go sailing right past them...

Maybe when I go FI, I'll dyno. Which has been on my mind more and more lately, since a friend just got an SMG e46 m3 and I'm going to have to do something soon Lol. That thing is fast!

-Dave

[NakNak]

Riotracing is going to post "biased" dyno sheets... we need a independent 3rd party to do back to back dyno runs on the same day, same dyno, with different TBs

I did a few years back. Dynoed my car with stock BBTB then I had a employee FROM Riot Racing install the Riot Racing BBTB while it was still on the dyno and then I re-dynoed. 0whp gain and I think 1 Tq. Not only that but later one of the 2 screws from the flap on the Riot Racing BBTB came off and got sucked into my motor destroying a piston and the head costing me quite a bit to fix. Of course I contacted Riot Racing and they assumed 0 responsibility and I had to pay for the entire thing out of pocket... If you truely are maxing out your NA engine and need a BBTB then go with the Bimmerworld 75mm. A quality part from a quality store that you know wont fall apart like some cheap pos...

[adamnur]

Oh my...

[KnudsonsM3]

Paying 700 dollars for 2 whp is the dumbest thing I have ever heard of.

[Brent 930]

I did a few years back. Dynoed my car with stock BBTB then I had a employee FROM Riot Racing install the Riot Racing BBTB while it was still on the dyno and then I re-dynoed. 0whp gain and I think 1 Tq. Not only that but later one of the 2 screws from the flap on the Riot Racing BBTB came off and got sucked into my motor destroying a piston and the head costing me quite a bit to fix. Of course I contacted Riot Racing and they assumed 0 responsibility and I had to pay for the entire thing out of pocket... If you truely are maxing out your NA engine and need a BBTB then go with the Bimmerworld 75mm. A quality part from a quality store that you know wont fall apart like some cheap pos...

Well well well, this is a Riot afterall.

Someones butt dyno is out of cal. OP?

[Estrl M3]

Nak Nak speaks the truth

[KGB7]

Paying 700 dollars for 2 whp is the dumbest thing I have ever heard of.

Up to 15HP.
http://store.bimmerworld.com/e36-big...ody-p1051.aspx




Or, you can get individual throttle bodies. Up to 40HP gain.

http://www.scottsdalemotorsport.com/E36Intake.html

[NeilM]

\If you truely are maxing out your NA engine and need a BBTB then go with the Bimmerworld 75mm.

The stock manifold's plenum intake port diameter is less than 70mm.

Neil

[JETninja]

One issue with changing out on the Dyno, doesn't give the ECU time to adapt. Your not going to see much if any change I would think.

[Marv17]

I just read the Ireland Engineering also makes a BBTB thats at 69mm at $205 ... i wonder what/how their quality is as well.

[adamnur]

^Good find, I've heard nothing but good things re: IE craftsmanship.

[Dmharvey]

the stock manifold's plenum intake port diameter is less than 70mm.

Neil

doh!