Big Bore Throttle Body. A worthy mod? Which one is best?

[RON98]

ill have a dyno at the shop with in the next 2 weeks

if anyone is in socal (los angeles) and would like to find out the difference in HP. i'll donate free dyno time to find out the difference once and for all.

We can also clean out a stock TB and see what kinda HP that puts out first than do the Bored out HP.

 

[LJSB]

ill have a dyno at the shop with in the next 2 weeks

if anyone is in socal (los angeles) and would like to find out the difference in HP. i'll donate free dyno time to find out the difference once and for all.

We can also clean out a stock TB and see what kinda HP that puts out first than do the Bored out HP.

So, first you dyno the car.

Then you clean the throttle body and I am supposing you know how (not meant to be wise here).
Dyno again.

Then you switch the throttle body and Dyno again.

Now for a control and to make sure you are not seeing variances of temp etc. have another car that you do nothing to and dyno that same car each time you dyno the car with the throttle body changes.

Wanna bet you'll see 5-10 hp variance at least on the control car too?

 

[NSXGMS]

Finally! The correct answer!
You sir have a brain.



WOW! Two for two. (Internet handshake!)

I try to educate as well as enlighten...

suckers are born every minute. I'm not sure why everyone's suddenly wrapped up in this AIS/BBTB whirlwind...hopefully after all this experimentation that's about to happen we'll at least have some definitive proof that they both are all but worthless, particularly on NA cars.

I'll never knock controlled, accurate experimentation even if it's a longshot based on somewhat anecdotal evidence. Fire up the dyno and maybe we can put the results in the FAQ. :smile:

 

[Stick-e-rice]

I was bored so I went shopping online and decided to get something for the car that wasn't too expensive. Impulse mod if you will.

It is snowing in Denver -5 degrees and my laptop is my friend.

Lots of high HP NA cars in Japan though, worth a shot IMO. Greddy does make an intake manifold that will fit the 90mm throttle body.

Is the AFC I bought sufficient to tune the car with this throttle body?

 

[RON98]

no, your not grasping the basic concept here. We are testing HP gains on one car. No control nessary.

im not sure why we need a control car.... do you see a reason? the cars are NOT idential....so even if both cars came factory stock the HP ratings wont be identical, thus a control car is pointless.

Warm up the car to operating temp, run the car with the stock dirty TB. Get HP rating. Clean the TB ... yes i know how... its not magic, i would not have offered if i dont know how.

Warm up the car. Run it with clean TB. Get HP

Switch out to bored TB. Warm up the car to operating temp. Get hp.

i dont see why there would be a variation in temperature if the car was warmed up to operating temp. To get the car to a consistant temperature, we can wait for the radiator fan to cycle on the first time after which we take the run immediatly.

Not like its going to take 2 days to change out a throttle body. Since shop temp's remain pretty stable during the day, we should not see a big drop in IAT temp. I wont be doing the work anyways. Im just donating the dyno and the shop space. We are not talking about different runs between different eng temp... ofcourse you'll see changes in HP.:biggrin: I seen cars gain and lose 20HP due to temp changes.

if no one wants to wrench, i'll donate one of my 2 nsx and we'll do the test on my car. Send it out to the shop, i do the runs and post results.... but im pretty sure some would want a few free dyno run on their car.

 

[Ponyboy]

Wow. No wonder part vendors don't mass R&D for the NSX. e-thugs shoot a potential hp+ part down even with someone offering to test it out.

Nice guys.

 

[RON98]

lol...

honestly tho, your getting free dyno time... who on earth in so cal gives free dyno time?!!?!!?!

scrach socal, who in the world gives dyno time!!???!?

ask autowave how much they charge for 2-3 pulls on their dyno

i should shoot myself in the face for just offering. maybe i should make it 50$ and people will come running since its such a bargin for 3 pulls.

btw what kinda stubid question is "if i know how to clean a TB?" i own a shop and can do a timing belt amoungst other upgrades on an nsx.

 

[nsxsupra]

Power gain aside, here is the side by side comparision pic.

Infiniti Q45 throttle body vs NSX throttle body.

Modied to work with NSX:

The plug and play Inifiti tb kit for NSX by Revolution is priced at 298k yen. Whatever price you got is probably a really good deal.

After some reading, the oem TB is 64mm.

Insert shamless plug here, I do have a oem intake manifold in case anyone is interested in using a spare to bore out and modified the intake manifold, $150 local pick up only.

 

[RON98]

ya its hell of a difference

Did you have to custom drill new bolt holes for the stock mounting location?

what custom work was done?

 

[LJSB]

no, your not grasping the basic concept here. We are testing HP gains on one car. No control nessary.

im not sure why we need a control car.... do you see a reason?

Yes. A having a control is standard scientific method when collecting, deciphering and comparing data.

 

[I1O101I]

Holy CRAP!!!! That is one Huge throttle body!!!!! I am going to have to get one.

Power gain aside, here is the side by side comparision pic.

Infiniti Q45 throttle body vs NSX throttle body.

Modied to work with NSX:

The plug and play Inifiti tb kit for NSX by Revolution is priced at 298k yen. Whatever price you got is probably a really good deal.

After some reading, the oem TB is 64mm.

Insert shamless plug here, I do have a oem intake manifold in case anyone is interested in using a spare to bore out and modified the intake manifold, $150 local pick up only.

 

[WingZ]

Power gain aside, here is the side by side comparision pic.

Infiniti Q45 throttle body vs NSX throttle body.

Modied to work with NSX:

The plug and play Inifiti tb kit for NSX by Revolution is priced at 298k yen. Whatever price you got is probably a really good deal.

After some reading, the oem TB is 64mm.

Insert shamless plug here, I do have a oem intake manifold in case anyone is interested in using a spare to bore out and modified the intake manifold, $150 local pick up only.

Wow thanks for this great info. Can you post the link to kit this kit? The $2500 is kinda pricey ,but still cheaper than ITB's. Did you do this mod? Thanks again man. Also where did you find the OEM TB info?

 

[WingZ]

If you get the Inifiniti TB from ebay like Ton at $100~$200. You can probably get it to work for far less than that. I don't know if there will be power gain, but investment is really not that significant even if it just give you better throttle responds. It is not the 5mm over stock big bore. It is 56% over stock mega bore.

I scaned the pic from the page 67 article "NSX Power Up Tunning Menu" from Hype Rev vol. 93. The OEM TB info is found from Revolution ad also Page 74 of Hyper Rev vol. 93. Revolution's announced that the NSX on line catalog with with new revo itb kit, 3.5L kit should be up on line, once they completed their suspension kit working in progress.

http://revo-tune.jp/info/article.php?subaction=showfull&id=1165540792&archive=&start_from=&ucat=4&

Thanks! looks like the NSX catalog is still down. When you say "3.5 kit" does this mean we can't use it on the 3.2's? Sorry to bug you ,but I'm really interested in doing this mod.

 

[Stick-e-rice]

I'm glad Jason has chimed in on this.

We might be moving somewhere now.

Let's all do some research on how to make this Q45 throttle body work in an NSX. I have a local shop looking at it when this thing arrives in a couple days, but anyone with specialty skills in this area?

This might be another good mod in addition to I/H/E for all the NA people.

I went ahead and bought the throttle body for a little over $100 and will play around with it.....see if it gets anywhere.

Honestly though. I don't know a whole lot about cars.

I'm glad Jason is helping chime in.:smile:

 

[TURBO2GO]

I wonder if the throttle body is a bottleneck with a comptech supercharger.

 

[ak]

I highly doubt piggyback like AFC would be good enough to tune the car with Infiniti Throttle body. I feel that there's just way too significant size difference. You'll have to really enlarge the intakemanifold inlet in order to get the most out of the bigger throttlebody. I don't know if the stock manifold can be enlarged that much though... It's kind of pointless to use bigger throttle body if the intake manifold inlet is still the same size.

Anyway, I would love to see it done properly with standalone ECU to see if it really makes any difference without killing the drivability of the car.

 

[WingZ]

I wonder if the throttle body is a bottleneck with a comptech supercharger.

Just couldn't resist could ya..LoL Actually I'd be very interested to see that type of application as well or maybe on VanceHu's car wow I can only imagine what gains his engine might make. Only drawback is I don't think he could use his Mugen intake with this throttle body.

 

[Stick-e-rice]

Just couldn't resist could ya..LoL Actually I'd be very interested to see that type of application as well or maybe on VanceHu's car wow I can only imagine what gains his engine might make. Only drawback is I don't think he could use his Mugen intake with this throttle body.

I've checked and found out that Greddy makes an intake manifold that will work on this 90mm throttle body. That is as far as i got.:biggrin:

 

[WingZ]

I've checked and found out that Greddy makes an intake manifold that will work on this 90mm throttle body. That is as far as i got.:biggrin:

Were you able to find out which intake? I saw this as well but can't seem to find which model on the greddy site.

 

[Daedalus]

I agree with the minority here...the VH45DE TB is not worth the mess that'll have to be sorted through to get it to work right. Has anyone compared the resistance values of the TPS's at various airflows? Cold idle will be close to 2000 RPMs, based on the Q's wax thermo-element. The TB is just one small component of a series of resistances. A larger TB will require an adapter plate to transition the flow from the larger TB ID to the smaller ID of the stock opening--the restriction will be shifted over. The stock TB is already 70% larger than the intake valve area of each cylinder.
If you want to quantify the restriction of the stock TB, the way to do it is to take a vacuum reading immediately before and immediately after the TB at steady state WOT. It will be slight at most and any improvements would be slighter still. If you do purchase a Q45 TB, stick with the '90-'95 models and avoid the cars with TCS, as they have a secondary TPS that would only get in the way.
Will it make a measurable difference? Maybe. The bottom line, IMO, is that any gains found won't be worth the cost/headaches/tradeoffs. FI applications may be a different story.

 

[Stick-e-rice]

I just sent out a couple of emails to ask for the specific model.

Will post as soon as I get more info. I wish somebody who was more knowledgeable will take on this project.

I don't know anything.:tongue:

 

[LJSB]

I agree with the minority here...the VH45DE TB is not worth the mess that'll have to be sorted through to get it to work right.

I absolutely agree.

 

[WingZ]

I agree with the minority here...the VH45DE TB is not worth the mess that'll have to be sorted through to get it to work right. Has anyone compared the resistance values of the TPS's at various airflows? Cold idle will be close to 2000 RPMs, based on the Q's wax thermo-element. The TB is just one small component of a series of resistances. A larger TB will require an adapter plate to transition the flow from the larger TB ID to the smaller ID of the stock opening--the restriction will be shifted over. The stock TB is already 70% larger than the intake valve area of each cylinder.
If you want to quantify the restriction of the stock TB, the way to do it is to take a vacuum reading immediately before and immediately after the TB at steady state WOT. It will be slight at most and any improvements would be slighter still. If you do purchase a Q45 TB, stick with the '90-'95 models and avoid the cars with TCS, as they have a secondary TPS that would only get in the way.
Will it make a measurable difference? Maybe. The bottom line, IMO, is that any gains found won't be worth the cost/headaches/tradeoffs. FI applications may be a different story.

At this point we do know that you can buy a kit from Japan to do this mod ( don't know if you read that or not ) so others are doing it it's just not anything someone has done here. Thanks for the tech info ,but again if there's a kit available someone has already figured this out. I honestly don't mind the nay sayers as positive needs negative. If it doesn't work out hey you guys warned us in advance , but if it does work it's a nice mod we can share with the board. In the US we do plenty of switching between Ford and GM stuff so why not Honda and Nissan parts? My concern is fuel as at this point if we're adding this much extra air we're going to need more fuel.

 

[RON98]

Yes. A having a control is standard scientific method when collecting, deciphering and comparing data.

yes you use a control if you have two identical items... with cars you dont have two identical cars so the control would be flawed.

if you can produce 2 identical cars with identical milage, idential maintaince history and identical driver habbits you got something going there. if you dont have, dont get anal on the testing. my procedure is pretty standard for a before and after install testing. dont be a troll.

 

[Stick-e-rice]

At this point we do know that you can buy a kit from Japan to do this mod ( don't know if you read that or not ) so others are doing it it's just not anything someone has done here. Thanks for the tech info ,but again if there's a kit available someone has already figured this out. I honestly don't mind the nay sayers as positive needs negative. If it doesn't work out hey you guys warned us in advance , but if it does work it's a nice mod we can share with the board. In the US we do plenty of switching between Ford and GM stuff so why not Honda and Nissan parts? My concern is fuel as at this point if we're adding this much extra air we're going to need more fuel.

If it doesn't work, put this on the list of another one of my bad ideas. I'm giving it a shot though, because this seems to be a popular mod in Japan.