75mm Throttle Body

[Mirage2LTurbo]

I've broken two BBK 75's and a stock Mustang GT 65mm TB and both look considerably stronger than that cluster#### pictured above.

Also, there are several people that have made mid 600whp on a stock NT throttle body, and several others making power in that same area on a stock throttle body. That chart that one of you "toonerz" posted up is completly false, and just a sales pitch some business posted on their website.

 

[PieTSI]

I've broken two BBK 75's and a stock Mustang GT 65mm TB and both look considerably stronger than that cluster#### pictured above.

Also, there are several people that have made mid 600whp on a stock NT throttle body, and several others making power in that same area on a stock throttle body. That chart that one of you "toonerz" posted up is completly false, and just a sales pitch some business posted on their website.

HAHAHA.

A sales pitch on a website? Its from a book, I quoted my source. I never said you could not make that much power on a smaller throttle body, although it becomes a major restriction. I am not going to post the entire article.

I think a book that was created with help from engineers from BMW, Audi, Jaguar, Ford, Porsche, etc. would have more correct information than you would.

 

[Hal]

I think a book that was created with help from engineers from BMW, Audi, Jaguar, Ford, Porsche, etc. would have more correct information than you would.

Posting those numbers with no other reference (airflow volume, displacement, etc) was a waste of bandwidth because taken by themselves, they mean nothing... regardless of the source.

Also, I wouldn't consider the source you quoted as "gospel". Many things have changed since that book was originally published.

Hal

 

[Mirage2LTurbo]

HAHAHA.

A sales pitch on a website? Its from a book, I quoted my source. I never said you could not make that much power on a smaller throttle body, although it becomes a major restriction. I am not going to post the entire article.

I think a book that was created with help from engineers from BMW, Audi, Jaguar, Ford, Porsche, etc. would have more correct information than you would.

That's great, but in the scheme of things, means about as much as a pot full of poo. I'm faster than you, which means I know more than you, so STFU n00b. Like Hal said, it's not a restriction, it's all in your st00pid theory. Just like you think of yourself as a t00ner. See the relation?

 

[GalantGst]

That's great, but in the scheme of things, means about as much as a pot full of poo. I'm faster than you, which means I know more than you, so STFU n00b. Like Hal said, it's not a restriction, it's all in your st00pid theory. Just like you think of yourself as a t00ner. See the relation?

im not saying ur right or wrong i ditn even read the whole thread(im not going any where near 500 hp i have a nt tb thats good enough)

but just because ur faster that dont mean ur smarter.
any one can just go out and order go fast parts and put it together.

 

[Mirage2LTurbo]

im not saying ur right or wrong i ditn even read the whole thread(im not going any where near 500 hp i have a nt tb thats good enough)

but just because ur faster that dont mean ur smarter.
any one can just go out and order go fast parts and put it together.

I'm sorry, who are you? That's great that you are content with your setup, I'm truly happy for you. So why did you post in here, and why would you post in a thread without reading it first? That's one of the dumbest things I've ever heard. Do you jump right into the gratuitous humping motion before foreplay as well?

People that buy "go fast" parts and put it togather get on here and make posts like "Running rich.. HELP NOW!!" or "Why is my car cutting out at 4297rpm?" After they figure out those problems, they are immediatly master t00nerz and ready to write their own standalone and run with the big dogs. I fart in their general directions.

 

[1fast97gsx]

Throttle plate requirements taken from: A. Graham Bell, Forced Induction Performance Tuning.

Throttle Plate (mm) | Max Horsepower for Turbocharged cars

50 250
56 310
62 390
70 500
75 600
85 750
90 830
100 1000

And you believe that nonsense? Lets use a 2g for example. We'll even say they have a 56mm throttle plate just for the hell of it. You're telling me a 2g can't make more than 310 hp on a stock throttle body???? I know people that have made 400+ and that's at the wheels.

 

[GalantGst]

I'm sorry, who are you? That's great that you are content with your setup, I'm truly happy for you. So why did you post in here, and why would you post in a thread without reading it first? That's one of the dumbest things I've ever heard. Do you jump right into the gratuitous humping motion before foreplay as well?

People that buy "go fast" parts and put it togather get on here and make posts like "Running rich.. HELP NOW!!" or "Why is my car cutting out at 4297rpm?" After they figure out those problems, they are immediatly master t00nerz and ready to write their own standalone and run with the big dogs. I fart in their general directions.

Why I jumped in? You say ur car is fast meaning you are smarter then every one else here?Wow u were able to go click some link and check out from website open the packages and assemble it on to ur car ? ur a genious

 

[Hal]

wow u are so smart

That is true, he exhibits having had some form of education... he uses decent grammar and spelling.

Hal

 

[GreenStreak]

Sometimes I wonder how people get any usefull information out of all the bitching that goes on here. :laugh: But then again there wouldnt be that much bitching if people didnt reply with stupid nonsense.

 

[91 white tsi]

I honestly was enjoying reading about the throttle bodies and the show and tell part then a bunch of childish games started. I was thinking of having my TB bored out and a new brass plate made since i know a guy that has done them for motorcycles as mentioned earlier in the thread. They gained 4mm on the motorcycle ones and it equaled 28whp which sounds small to us but for a bike thats like almost a 5th of their power?!?! so i know we wont have quite that much of a result but what kinda power are you two that have ported ones seeing? what did you port? stock turbo tb or the nt tb? and how much over did you go? did you have to change anything else other than the blade? and what mass are you talking about removing? lets get back on topic so some of us can learn

 

[PieTSI]

And you believe that nonsense? Lets use a 2g for example. We'll even say they have a 56mm throttle plate just for the hell of it. You're telling me a 2g can't make more than 310 hp on a stock throttle body???? I know people that have made 400+ and that's at the wheels.

Read my followup post.

 

[PieTSI]

I'm faster than you, which means I know more than you, so STFU n00b.

Your faster than me so that means you know more than me? This comment makes you look even stupider.

Did you ever take in effect that maybe I drive this car everyday, and I modified my car to a moderate power level where it would be cheap, reliable, yet still be decently fast on pump gas?

Anyways I didn't write the book, I posted info from it, and if you guys don't want to beleive it, I don't really care.

 

[91 white tsi]

apparently you didnt read the post above your two that says lets get back on topic

 

[Tallen]

You all need to stop pissing in the wind and get back on topic, I do agree. And for gods sake, learn some decent insults if you are going to be so bold...those above are just pathetic. I am very disappointed and drunk.

 

[Hal]

so i know we wont have quite that much of a result but what kinda power are you two that have ported ones seeing? what did you port? stock turbo tb or the nt tb? and how much over did you go? did you have to change anything else other than the blade? and what mass are you talking about removing? lets get back on topic so some of us can learn

All DSM 1g turbo throttle bodies and the 1g N/T share the same base casting and are bored to 60mm at the throttle shaft by the factory. For the most part they share the same parts. There are some minor differences, but nothing worth noting.

When boring them out, you can go out to about 63mm before you hit the throttle shaft bushings.

You don't have to change anything but the plate, however if you study the throttle plate closely, you will see it's not "round". It's actually an ellipse that seals the shaft when it gets to within 3 degree of vertical.

The throttle shaft is a 10mm steel "rod". About half way down it's length is a groove into which the throttle plate sits.

When the plate is bolted in place, the groove acts as a clamp. This means the groove takes the angular loads imparted on the shaft from high pressure and/or vacum levels rather than the 2 screws that hold it in place.

The mass being discussed is the removal of the the section of throttle shaft on one side of the groove.

So, instead of a round shaft, it is now "D" shaped.

When the section removed:

1) There is no longer any clamping force on the plate
2) The 2 throttle plate screws now are the only thing holding the plate in place
3) 50% of the throttle shaft cross section has been removed, making it less resistant to the forces imposed upon it.

As far as performance goes, no dyno numbers yet... but it's not a high priority.

Unless you are racing in a class that requires a stock throttle body, I don't see boring it out to be really practical. I would say that 90% of the people who have an aftermarket throttle body on a DSM don't even need it. For the ones that do need it, the extra 3mm gained by boring the stock body isn't worth the expense.

Hal

 

[Car Cannibal]

Forgot, I can not completely eliminate both sides of the shaft, still some gain in flow though.

Not sure who's TB you are referring to Mirage but a cluster**** is definitely not what my TB is.

If you slap on a 63mm and do not match the intake, its pretty pointless and not worth doing.

 

[Mirage2LTurbo]

Forgot, I can not completely eliminate both sides of the shaft, still some gain in flow though.

Not sure who's TB you are referring to Mirage but a cluster**** is definitely not what my TB is.

If you slap on a 63mm and do not match the intake, its pretty pointless and not worth doing.

We'll see how that shaft holds up into some boost.

 

[Car Cannibal]

Like you know right?

Why don't you go ask the GN guys with their 62mm, half shaft, bigger turbo's, no blow offs, guys how many of their TB's died. Then ask the guys who machine those for them on how many have EVER failed. Your answer will be ZERO!!

 

[Hal]

Then ask the guys who machine those for them on how many have EVER failed. Your answer will be ZERO!!

That'd be great if you were using a GN throttle body, but it's your car.

I wouldn't do it on mine or any other DSM.

 

[Mirage2LTurbo]

Like you know right?

Why don't you go ask the GN guys with their 62mm, half shaft, bigger turbo's, no blow offs, guys how many of their TB's died. Then ask the guys who machine those for them on how many have EVER failed. Your answer will be ZERO!!

I know I've broken enough throttle body shafts that I don't want to half-ass (literally) one. That's great that the GN guys don't break them, have you ever seen the design of one of their t/b's versus ours?

 

[Car Cannibal]

Hey guys, have you ever seen Ace Ventura?
I think you both need some breath mints.
Your just guessing at whats going to happen and thats probably due to all the problems the aftermarket has caused. But relax, here are some more FACTS on my cluster**ck TB.

The DSM shaft is LARGER than the GN shaft, picture below tells it all.

My machinist has done over 300 GN half shafts with ZERO breakage and this is on a thinner shaft and no blow off to help out like the DSM's have.

I hear you if you say why do the half shaft over the full just for the extra insurance, but my machinist has plenty of proof that there are no worries. I trust him so I went with the extra flow gain instead.

I would bet that the rockwell on the aftermarket shafts is to high making it way to brittle.
I would stay away from any of those TB's and do a ported stocker or buy any new DSM big bore TB.

 

[Mirage2LTurbo]

I know of several Turbo Buick's locally making upwards of 500-600whp, and none of them are running this so called t/b mod you speak of. This is what I do know, however. I'll let the pictures speak for themselves, while your research is all theory.

 

[Hal]

The DSM shaft is LARGER than the GN shaft, picture below tells it all.

My machinist has done over 300 GN half shafts with ZERO breakage and this is on a thinner shaft and no blow off to help out like the DSM's have.

I hear you if you say why do the half shaft over the full just for the extra insurance, but my machinist has plenty of proof that there are no worries. I trust him so I went with the extra flow gain instead.

I would bet that the rockwell on the aftermarket shafts is to high making it way to brittle.
I would stay away from any of those TB's and do a ported stocker or buy any new DSM big bore TB.

The two shafts look about the same to me, certainly not much difference.

What is your machinst going to do when (not if) this fails?

I wouldn't "bet" on anything, but since you toss out the theory of the shaft being to brittle, you are suggesting that the shaft flexes.

If the throttle shaft is flexing, doesn't it follow that reducing it's strength probably isn't the smartest thing to do?

Hal

 

[Car Cannibal]

Go here www.turbobuicks.com and ask around on who has the ported TB, tons of guys do. Its a popular mod due to the really low price. A lot of guys also go with the Accufab 70mm, and no ones ever broken one of those either. But then again, those TB's are GN specific.

No theory here, my machinist has been apart of the facts on this mod for turbo cars.
Saying that its a cluster**ck and not knowing that there are well over 400 half shafted TB's on different turbo cars sounds like something else to me. DSM's are not some freaknoid disasters that will break every part not engineered by Mitsu. Hell, don't you run an E85 conversion 2.0? I bet that had a ton of bombs waiting for you when you talked to others about it. Hows your car doing after the mod? Is it a cluster**ck? I think I read its running fine on like 1600cc injectors.

The BBK looks like its really thin near the bolt holes. I wonder if the screws are bigger than the stock TB's and thinning out the shaft even more. Any chance you can get some measurements Mirage, shaft size and screw size would be helpful. I can get the stock screw size and compare.

There is not much difference in thickness, but the DSM shaft IS bigger. Then add that there have been zero GN breakage's ( all half shafted ) does allow for some thought that the thicker DSM half shaft with a blow off and a smaller turbo should have LESS stress on the shaft.

"When it fails", come on Hal, no one knows until its tried but IF it does fail, I will get another one full shafted. I know that one will not fail for sure. But what if I go a year and nothing happens? No one would of known it worked until it was tried.

Hal remember, this HAS been done on many turbo vehicles. All the SRT's my guy does have all been fine half shafted and all of the over 300 GN half shafts have been fine with no breakage either.

Is it a smart move to go half if its not nessasary?
So far where's the proof on any turbo vehicle to NOT do it? I am pretty sure the half shaft SEEMS risky in this crowd due to all the aftermarket failures. The funny thing is that my machinist said this question has never been brought up on any of the vehicles he has done this for except the DSM's.

But the thing here is that you do not HAVE to go with the half shaft. Go with the full shaft and guarantee that it will not break.

Anyways, I would rather go ported 66mm full shaft over the BBK, plus the 66mm is much cheaper and bolts on etc.

No flames guys , but I bet if I went through all the stuff you guys have done over the years to your DSM's, there are a bunch of things that are not by the book.