omniserv

I have installed a 60mm throttle body on my stock NA and wow it made big diff. Well at least when the engine is cold. Once it warms up or 2-3 mins after starting it the power drops way off. I have been fighting this problem for a long time.

The power the engine has when cold is amazing, it's hard to keep it from burning the tires off. this makes me think that the problem is not fuel or ignition (tune up) related. Rather it's something to do with what valves the ECU changes after warm up.

Any body have any idea's??

Chris

AZ-ZBum

placebo effect.
snake oil.
empty wallet syndrome.
sugar pill.

It's been proven that the 60mm TB does absolutely nothing on a stock plenum.

http://z31.com/board/read.php?id=54693

omniserv

I know it will make a very small diff. With the way this car acts cold vs warm it's hard for me to tell what's going on.

This link has some data.
http://www.redz31.com/pages/plenums.html

I have a stock intake at a shop being gutted right now. I'm going to put it on the same time I do a turbo conversion.

AZ-ZBum

Those are different than stock plenums.

And no, it won't make a lick of difference. Didn't you read the post I linked? That's done by the same person.

jfairladyz

It's that increased throttle response that makes it feel more powerful. For less throttle input you're letting more air by. So you get the illusion that the car is going faster.

AZ-ZBum

I take it you didn't read the link either?

jfairladyz

It's not rocket science dude. And I wasn't talking about maximum flow. If the bore is bigger then more air will flow at a given throttle position. Think about it for sec. At 1/4 throttle, the 60mm TB will allow more air to flow then the stock TB will at 1/4 throttle. If you can't comprehend that then it's time to go back to school With smaller throttle inputs you're nowhere near maxing the potential of the stock plenum. So yes, increased throttle response. I said nothing about more flow.

and I did read the link. You quoted it almost in its entirety. Which makes it a really good link since it has no evidence to support it's claim

AZ-ZBum

doesn't matter. the fact that the bottle neck is the plenum and not the throttle body negates any changes that you do to the throttle body (unless you go smaller). Throttle responce? Actually, if you think about it, the 54mm would be easier to control the amount of air. Since you can only flow so much, the 54mm would allow tighter adjustability. The 60mm might have the same effectiveness at 80% open as at 100% open. Therefore, you would have 20% of useless throttle.

So what if the 60mm allows more air at 1/3 throttle than the 54mm at 1/3 throttle. The 54mm allows the same amount at slightly more foot pressure. So what's the big deal? Relative position is irrelevant as long as the stock TB opens all the way up. This fact remains: The 60mm TB cannot provide more air to the engine than the 54mm on the stock plenum.

As far as the information and source, Jason is very thorough in his research.
You can get the stock flow numbers here:
http://www.redz31.com/pages/plenums.html
And read the comparison numbers here:
http://z31.com/board/read.php?id=54738&srf=nyet

SHADY280

i dont know why you guys even try to argue with this guy, hes got a carrot up his @$$, and somebody pees in his corn flakes every morning when hes not looking. we need dyno testing to prove this one, i installed one on my car and it definately seems to have made some difference, espesially in the exhaust note. hmmmm. almost like its flowing more air.

jfairladyz

See I'm not talking about throttle control or even if the 60mm can provide more air. Throttle response is neither of those. For less throttle input, you'll get more air flowing into the engine. That's throttle response. Again, you're missing my point. Like I said, at 1/4 throttle the stock plenum is NOT a bottle neck. At WOT, sure it's the inhibiting air flow. But that's not my point. My point is that the bigger TB give more throttle response with less input. Period. And that is why I used such a small amount of throttle for my example. Cause that is where the illusion comes into play. When you give it only a slight amount of throttle with the bigger TB and the engine responds as if you were giving it more throttle with the smaller TB. You can try to argue against that point all you want. But in the end, that's just how it works. So again, it's that throttle response that gives the illusion of more power.

And the numbers in the links dictate valve lift. Not throttle position. So those numbers have nothing to do with determining throttle response.

jfairladyz

SHADY, on your car I'd be willing to bet it made a difference. The L series manifolds aren't very restrictive (with the exception of the TB opening). So a proper port of the inlet would take care of that. And you've got a motor modified to flow plenty of air. So in your case I'd say it's definitely got to be helping Plus the fact that the L series actually had a 60mm throttle body manufactured just for it tells me that the potential for more flow was there.

NismoPick

Does anyone watch HorsePower TV of the "PowerBlock" on Spike TV??? Just this morning the 2 guys installed a larger 70mm TB on their Fox body Mustang, along w/ a larger intake pipe.... Dyno before & dyno after.... After dyno: 9 more hp.

Sounds like it's the Z31 plenum that has the issue then... because other cars have DYNO results of increased hp.

Where's this guy's before & after dyno charts? Sounds like he really wants to prove this theory wrong... but we wanna see DYNO proof... not "on the workbench" proof.

SHADY280

that did anybody read omni's plans for the car, he said turbo, then it will make a diff. specially with a port match, it would be stupid to upgrade a tb and not port match, it so easy, if you got the tools. a 70mm on a fox body makes a pretty good diff. i know cause ive done the upgrade myself. it adds lots more bottom end torque and just a little hp by the feel of it. add better ignition and hold on.

AZ-ZBum

So all you have to do is put your foot down a little more. What part of that don't you understand?

With the 60, you put it down 1/4 and get a certain feel.
Well, BFD! So you have to put your foot down 1/3 to get the same feel with the 54.

NismoPick: I agree. Show me on the dyno how it affects the car. Everything I know about dynos says that you measure HP at WOT. And racing is typically done at WOT. And since the bottleneck has been proven to be the plenum and not the throttle body, you will never see a benefit on the dyno.

On some cars, the TB may be the restriction. But it's now been proven that on the Z31, the restriction is NOT the TB.

Which brings me back to:
placebo effect

nismo619

60mm ? 64 mm , 100 mm ? i belive it doesnt really matter.. if it give u more HP to the wheelz thats all wat matters but since were on that note.. what is the largest throddle body that the nisan 280zx turbo intake manafold can take ? i saw a 90mm throttle body off a q-45 on ebay for sale.;..

nismo619

hey check this out.. it says it works iwht te 240sx ? same as the 60mm every boy is puting on there 280zx's right ? but look at this http://cgi.ebay.com/ebaymotors/Q45-B...spagenameZWDVW


this is double the capacity than the stock 280zx throttle body right ? all u would have to do is bore out the opening on the intake manafold right ? prety much swap over the parts to link up to the stock linkage onto the 280zx right ?

entropy31

i will forgive your atrocious spelling and grammar this time, however, i believe these are questions that would be better answered in the 280zx forum. this would be the z31 forum. please keep your posts legible and in the proper forum, or i will just delete them.

jfairladyz

Thats my whole point. BFD is right. I was never disputing whether it made more power or not. I specifically said that the increased throttle response is what gives it the illusion of having more power. You put the pedal down less and your car goes faster then it did before with the same amount of throttle input. Of course with the restrictive intake manifold this only works at the lower RPM's, and thats where the misconception of more power is usually felt.

It is a placebo effect. And I never disputed that. I simply stated why you can actually "feel" this placebo effect taking place.

SHADY280

its funny to watch the exact same point argued from differnt directions

FreeLanceBum

I agree Shady

omniserv

Hey guys, Looks like I started a small war, only to find you guys agree with each other anyways.

Since I just made to change to the 60mm TB I can say that the diff. feel only lasted the first few times I drove the car. Once I got used to how much pressure was needed on the throttle to move through the gears I can't tell the diff. at all.

Like I said a shop is gutting a stock intake as we speak, plus I'm buying a 85 turbo car to use a donor car for the conversion. Although the car might be a litttle to good to junk..??? I have a bunch of questions about the NA vs Turbo engines, they are in the engine forum.

Thanks

Chris

SHADY280

see, he was taking care of the intake anyway, helps if you read the first q posted by the guy wanting the info!!! that and he wants to use it on a turbo engine, not just na. itll make a diff. then, not really worth arguing about

b1oodpaint

I get exactly the point az-z bum is making.

yoo guys are the wall this grenade is hitting.

chubbshwc

hey how much for the parts car

omniserv

The parts car i have has been cut in half and ready for the dumpster. I do have a lot of parts from it.