vrus

Huh? You mean this one with the pics in it??

How could there be a worm notice? I view my posts from work and client's sites and I've never received any warnings.. The pics were snapped at home, uploaded to my website and posted here... Should be no problems..

dsc

Victor, can you give me your bank account number and routing number. I'm arranging to have my paycheck directly deposited in your account from now on. You can send me mods as you see fit.

vrus

Vrus' Mod of The Month Club.

DSC - Member #0001

Grumpy666

This statement is puzzling me a little. I've been thinking about it since you posted and cannot come up with a valid reason why a larger TB should improve part-throttle response (assuming your bypass valve wasn't stuck in the closed position prior to the install). Since the same amount of gas pedal movement is now flowing more air, I think that you're not yet calibrated to the larger TB. You're used to a slower acceleration rate with old TB. If this is accurate, then look for your gas milage to go down until you adjust. What do you think?

vrus

I know.. It's strange... I never expected it to be this way.. I spoke to my friend with Kleemann K4 and he told me throttle response got worse with 80mm TB so that's what I was expecting with my car. When I told him about what I felt, he was suprised to hear it too..

Maybe there is a difference between the V12TT TB and the AMG 80mm TB?? Stepper motor actuation?? Don't know really... I know it's not my imagination.. Car definitely responds quicker to throttle input.

The real answers will come once 2 or 3 other people install their kits... there should be enough feedback to form a proper conclusion.

For now, I am liking it..

MACHC5

It just happened again Norton picked it up again when I tried to look at page 6 of this thread.

MachC5

vrus

It might be Norton acting up because I put my email address as a link in the post.. There is nothing wrong so please dont worry..

E.fifty.5

Hey victor,

I took my cousins sl65 for a ride today and the destination is my friends workshop....he removed the TB and measured it.. and guess what...its 80mm. The TB is also the same as Kleemans ....check your e-mail...i Have a stock and kleeman TB if you want some pictures and measurements...Peace

Hope my cousin never reads this post....shhhh

vrus

Khaled,

Take alot of pics!!! If they are the same, then just take some front, back and side shots of the TB.. Get closeups of the front and the back.

I'll PM you my #.

E.fifty.5

Victor,

i know ive sent them to you already...but this is for the forum

Jakpro1

Oh, I get it noowwwww.

So the plate that we are waiting on is the plate she will mate up to.

It just clicked when Art posted the Renn TB.



Quick question V....what are all the connections to the left of the this TB.....ours are not like this right? Just pretty much a solid piece of billet right?

I am kinda lost on the TB, but trying like hell to get this.

Think I got it now.

Guess just a visual guy I guess.

vrus

Khaled: Thanks for putting up the pictures for me.. Finally I've gotten a chance to see what the V12TT TB looks like.. I was wrong about the PCV connector.. It does have one on the bottom but it comes plugged up.. Essentially they look to be the same in design and function..

The only difference is the wiring output, the price, and the availability.

For some reason Renntech chose to use the AMG 80mm part and Kleemann is using the V12TT TB part.

-------------------------

Jim,

Yup. The plate we are waiting on adapts the mounting holes on the AMG 80mm TB. It basically provides a new "neck" for the supercharger inlet.

One thing I discovered is that the kit I put together is the EXACT kit that Renntech is selling for $3995 and I didnt even know it... Renntech is using the AMG 80mm TB and they are even supplying the 80mm Y-pipe like I do.

So after all the work, I came up with the same solution that Renntech is providing to its customers and I had never seen the Renntech kit before.

There are a few things I discovered also which are interesting.

- The V12TT TB and AMG 80mm TB both have 80mm bore size and both have a small step-up just before the throttle plate that transitions to 79mm.

- The throttle plate is actually 78mm in diameter.

- The exit bore is also 80mm like the front.

What this means is that if more power is extracted from these motors, based on wall thickness these 80mm TBs can be bored out to at least 81 or 82mm if needed.

Vadim did say that when he bored the stock one out to 76mm he was able to cut the vacuum across the TB down in half.. Going another 2mm to 78mm throttle plate must be enough to eliminate the vacuum and feed the motor the air it needs..

I think anything bigger would just be worse and that's why everyone stopped at this point. Once the power levels reach 700hp we may need to bore these babies out to 82 or 83mm..

vrus

Jim,

BTW, the pic you are seeing of the Renntech TB and that piece behind it is the supercharger Inlet.. It is a stock supercharger inlet which Renntech has bored out but when they mount on the new enlarged neck, instead of putting on a square piece of aluminum they shape it to the contours of the TB so you dont see anything.

If you look a few pages back, I posted pics of the new inlet with the mounting plate attached to it.

All the connectors you see on the left of the pic are just vacuum hose connections.

W211E55

Victor, can you do this as well for your kit?

Grumpy666

OK, I'm not understanding this - what are you trying to say here?

vrus

Its alot more time and effort.. The machine shop is already taking alot of time to do it as a square.. It really doesnt look to bad so I dont want to mess with it right now.

Well... Remember back when I posted that Vadim checked the vacuum going across the TB and he found 30in of vacuum? And then, when he ported the TB to 76mm he saw that drop to 15in of vacuum and gained 18rwhp and 15rwtq.. That's what I was referring to..

Although, now, thinking about it, he bored the TB to 76mm which means the actual throttle plate is probably 74mm on the stock ported one..

This new one is 80mm bore with 78mm plate..

vrus

By the way.. Thanks to my new friend Khaled (E.fifty.5) from Dubai for doing all that work and getting those pics..

Getting information about anything for these cars is like trying to pull teeth... Everything is so hard to get info on.. You basically have to just buy anything you want to look at because no one is willing to share info.

Thank god for communities like this!

You guys know that he took his cousins SL65 and pulled the TB off just so we could get a good look at the stock V12TT TB.

Thanks Khaled for helping out the community! You are a good dude!

Grumpy666

Yeah, I remember that - and I also remember that I didn't understand then how the vacuum level at the TB relates to a power increase in the engine. What am I missing here? Also, is that 30" of water?

vrus

Huh?? I thought you posted and said that when there is 0" of vacuum that means that the motor has taken all of the air that the TB can flow and consumed it..

I thought you said when there was vacuum present at the TB under WOT that the motor is starving for air and there is not enough flow to satisfy it and therefore the vacuum is present..

Am I remembering all of this incorrectly?

vrus

This is the post I was referring to that you made on Page 1 of the thread:

GTA23109a

Ehhh . . . so am I going to have to send my new TB/housing out for porting once I get it??

vrus

No.. Everything that is supposed to be ported is ported..

I just wanted to share that all the TBs are 80mm bore but the actual throttle plate is only 78mm. That's why I wanted to compare the V12TT TB to the AMG 80mm TB.

The TB has room to grow if you want to go bigger, but there is no need at this power level. It seems to be the magic combination to provide the airflow the motor needs.

Just know that there is room for growth if the TB becomes a restriction later on.. It can be opened up at least 1 or 2mm more when needed.

Grumpy666

No, you aren't, but, I seem to have trouble remembering that these engines are supercharged. What I stated is valid for NA engines - at WOT, your engine is under boost, so there will be no vacuum. Plus, the S/C isolates the TB from the intake plenum. Sorry for the confusion - my fault.

The vacuum that Vadim measured must have been venturi vacuum from a port in the side of the TB (caused by the airflow through the TB). The fact that it went down after boring indicates that airflow velocity was reduced, which makes sense. This vacuum is not an indicator of the engine's airflow capacity, just the airflow velocity through the TB.

vrus

Grumpster..... Work with me here... LOL... Please remember that it is already difficult trying to understand engines and wrap my head around this stuff.. I'm just a techno geek... LOL.. Don't confuse me and make it even harder...

Great... There... Now I need an aspirin... Thanks!

Ok.. So on a F/I motor what does one measure to determine if the TB is a restriction or if it is adequately sized?

Grumpy666

This is less straight-forward than for a NA engine. For a FI engine, the TB is actually sized to feed the S/C, not the engine, per se. And that sizing is for a given boost level (S/C speed). If you change the boost level (ie, go higher), you will probably need to change the TB to maintain the optimum size.

If a TB is too small for given boost level, then the S/C is not producing as much boost as it could. If you feed it more air by increasing the TB size, the boost level will increase. When the boost level stops rising, the TB is sized correctly. Conversely, if the TB is too big, boost will at its maximum for that S/C speed. When sizing the TB smaller just causes the boost to start to drop, you have found the optimum size.

The good news is you can go too big with a TB and not pay a penalty like you would with a carb. The TB doesn't meter fuel, so it won't affect the tuning like a carb. A too-big TB will only pass as much air as the S/C requires, whereas a too-small TB will restrict air flow at upper RPMs. The only downside to going too big is you could experience surging and eratic slow-speed acceleration at part-throttle conditions. With a too-big carb, low-speed throttle response suffers since the vacuum signal needed to meter fuel is weak.

Since boost is affected by many variables, you can probably appreciate the difficulty in sizing a TB correctly. From a performance perspective, you're better off a little too big than a little too small. It would be interesting to see what the 80mm TB does to boost level on a stock engine.