Dinan bored throttle bodies with supercharger?

[8500RPM]

Replied to a comment on some E92 M3 Instagram where the guy was supercharged and someone commented to get Dinan bored Throttle Bodies. I mentioned money would be better spent elsewhere but the guy claimed that he's seen multiple supercharged M3's gain 30ish WHP just by going to Dinan Throttle Bodies. I've been on these forums for about 2 years and never read anything about such gains.

Anyone have any comments? Mostly just peaking my curiosity but as everyone here I see a supercharger in my future.

$2000 for 30 WHP on this chassis doesn't sound crazy to me.

[pbonsalb]

Bigger TB go great with bigger airflow. But since you are NA now, I’d put the $2k towards the supercharger rather than small NA gains now.

[Scharbag]

I have dinan throttle bodies. Previous owner put them on. Pretty sure they are a total waste when NA.

That said, they might help with an FI engine. Even then, are the throttle bodies really a major bottleneck in the S65? The total surface area is pretty large to start with. Not actually able to quickly find the stock diameter, but there are 8 of them. Pretty sure the combined area of the S65 is greater than the typical MAF sensor area in other high horsepower NA cars.

Also, NASCAR could still make big HP with restrictor plates that were only 1" in diameter.

Cheers,

[8500RPM]

To be clear im not interested in Dinan throttle bodies for my NA motor. Just wanted to open discussion on the topic for anyone that actually has experience with Dinan throttle bodies and superchargers.

I'd never heard of such claims on this forum which is why I ask. Like I said if true supercharged people who want max power would welcome an extra 30WHP. Would love to see back to back dyno charts.

[OmairK]

I'm in for info on this as well. From the other threads I read, people couldn't get them to work right and they weren't worth it for the amount of power gained. I definitely want to pick up a used set if anyone is selling!

[SYT_Shadow]

Originally Posted by 8500RPM

Replied to a comment on some E92 M3 Instagram where the guy was supercharged and someone commented to get Dinan bored Throttle Bodies. I mentioned money would be better spent elsewhere but the guy claimed that he's seen multiple supercharged M3's gain 30ish WHP just by going to Dinan Throttle Bodies. I've been on these forums for about 2 years and never read anything about such gains.

Anyone have any comments? Mostly just peaking my curiosity but as everyone here I see a supercharger in my future.

$2000 for 30 WHP on this chassis doesn't sound crazy to me.

well, where are the entries in the S65 dyno database that show +30whp? You would think the word would be out by now

The two entries I've seen in the dyno database on NA engines (one 4.0L and one stroker) show zero gain. Which is why my stroker doesn't have them.

[SVH]

I believe RG did it. There was a post awhile back which discussed this issue. The before and after on his SC engine indicated a loss of 4 hp.

[Green-Eggs]

Originally Posted by SVH

I believe RG did it. There was a post awhile back which discussed this issue. The before and after on his SC engine indicated a loss of 4 hp.

I think SYT is right; it was for NA, not supercharged.
http://www.s65dynos.com/showDyno.php...ype=1&dynoID=1

[Scharbag]

The attached photo (thanks to Scott R. Lear for posting these) shows the intake right to the cylinder head. Not totally sure where Dinan bored the throttle body by 8%. I assume they did not introduce any "steps" in the material. I know there is no head work required for the installation so only the very top of the intake runner would be larger to maintain the "trumpet" like shape to maximize airflow.

Also, an increase of 8% in area is 4% increase in radius or a 2% increase in diameter. The S65 stock ITBs have been shown (by Danny and others) to make BIG HP or NA motors. Surely if they were a bottleneck on the stock motor, the stroker guys would have figured this out by now.

Finally, there has been some massive power numbers put down with the stock ITBs when supercharged and turbocharged. It does not seem that the factory ITBs are a bottleneck. I could be totally wrong, but I just do not see the value in the Dinan throttle-bodies. I have them, and if they were not such a PITA to remove, I would be happy to sell them for stock units and spend the money on something else.

Cheers,

[SYT_Shadow]

Originally Posted by Scharbag

The attached photo (thanks to Scott R. Lear for posting these) shows the intake right to the cylinder head. Not totally sure where Dinan bored the throttle body by 8%. I assume they did not introduce any "steps" in the material. I know there is no head work required for the installation so only the very top of the intake runner would be larger to maintain the "trumpet" like shape to maximize airflow.

Also, an increase of 8% in area is 4% increase in radius or a 2% increase in diameter. The S65 stock ITBs have been shown (by Danny and others) to make BIG HP or NA motors. Surely if they were a bottleneck on the stock motor, the stroker guys would have figured this out by now.

Finally, there has been some massive power numbers put down with the stock ITBs when supercharged and turbocharged. It does not seem that the factory ITBs are a bottleneck. I could be totally wrong, but I just do not see the value in the Dinan throttle-bodies. I have them, and if they were not such a PITA to remove, I would be happy to sell them for stock units and spend the money on something else.

Cheers,

great pic!!!

I saw a set of these for the S54 and exactly the point you're making: the head is unchanged. Very skeptical of Dinan's claims.

I wish they made 30whp, I would be the first to buy them!!

[8500RPM]

Nice to see we have a little discussion going here. I’m gonna reach out to the guy on Instagram to see if he’s a member here so he can share his input.

[TomHudson]

Dinan claims 7 hp.
Which claim are you referring to?

[8500RPM]

Here is the claim that started this all...

[Green-Eggs]

We did the work on Bert's car used in that dyno test. We installed the throttle bodies.

IIRC, they are 2mm larger diameter than the factory throttle body bores. Yes you would need to make a new butterfly. Don't even think about trying to make them yourself -- it's a nightmare. We had a very qualified machine shop try it, and eventually gave up because we couldn't seal the new butterflies well enough.

But let's assume you can bore them out and make new butterflies (which are slightly oval shaped...BTW), that's where the next fun begins. You'll need to reattach them and time them with the DME software. It's not easy at all.

[Scharbag]

Originally Posted by Green-Eggs

We did the work on Bert's car used in that dyno test. We installed the throttle bodies.

IIRC, they are 2mm larger diameter than the factory throttle body bores. Yes you would need to make a new butterfly. Don't even think about trying to make them yourself -- it's a nightmare. We had a very qualified machine shop try it, and eventually gave up because we couldn't seal the new butterflies well enough.

But let's assume you can bore them out and make new butterflies (which are slightly oval shaped...BTW), that's where the next fun begins. You'll need to reattach them and time them with the DME software. It's not easy at all.

So given I have the Dinan ITBs, are there any concerns with running non-Dinan software?

[Green-Eggs]

Originally Posted by Scharbag

So given I have the Dinan ITBs, are there any concerns with running non-Dinan software?

After you remove the TBs from the shaft, the opening and closing adjustments are lost. When you reassemble, theres a calibration procedure in ISTA to realign them and set the idle. This is where we gave up after our modified ones could never pass the alignment and idle vacuum tests.

This is what I meant earlier. So you dont need any custom DME software to run them.