Larger KA Tb's

Hey everyone.. was just talking to a mate of mine (chr1s) who has a pair of KA24E tb's.. and he heard that they are dirct bolt up to the Z32 same bolt spacing. is it as simple as removing the old tb's and putting new ones in or do i need to modify the linkages and do the intake pipes need to be inlarged to fit over the new tb's i beleive they are 5mm bigger. i also no that i will need to reset my tps so my laptop will be charged and waiting..

any help as always is greatly appreciated

its a NA by the way

Cheers James

 

I think there would be quite a bit of mucking around to make them work. Will the TPS connect up? Does the KA TB have a TPS? You might be able to use that if it has the same analogue output.

I think for the amount of mucking around I would just buy a set of bored out ones from UAS.

Let us know how it goes.

 

Refer to here for larger throttle bodies.
http://twinturbo.net/net/viewmsg.aspx?forum=main&msg_id=931443

 

from what i hear, throttle bodies aren't much of a bottleneck in the induction tract of the vg30dett, at least not relative to other restrictions. prob a lot of work for little gain.

 

Larger TB's

are not much use, unless the intake pipes are upsized.
Even then the gains are small to non-existent according to people who have done this mod.

 

sif not ask me before you posted james,

i'll whack them on his car, i may need to port out his plenum though..

bolt spacing should be fairly similiar if not the same, and yes it does use a TPS

0-5V, same as most other nissans. even if it did have the wrong sweep, error percentages/degree of opening i can always make up a board that can regulate this, up to an extent.


I'll keep you posted guys. Should be good info for you guys, also for TT.

 

You throttle response would be a bit worse

 

Why don't you just use the existing TB's and get the cheap bore device from supercheap and use that to open them up from 50mm to 63mm and just replace the butterfly for an appropriate one (63mm)

63mm is about 2.5" and you can change your intake piping *from* your IC to your TB's to match

 

Unfortunately not quite possible. The TB's are a tapered design, larger at the front and going narrower at the rear. The max you can bore the OEM ones out is 4.5mm internally, after that you will break into the inner side wall and feck it up. A custom butterfly is easily made to mate up to the bored out TB though. Obviously not forgetting to bore out the plenum opening to match so as to avoid a "step".
Bare in mind of course, whilst the TB's seem fairly small compared to other engines, each one only serves a 1.5cc engine and thus usually those who have pretty much exhausted most other avenues of gaining power, would really benefit.
Hope that helps!
smithy

 

Especially on an NA, complete waste of time...

 

er,

have some of you guys heard of custom piping? lol...

and also, fellow automotive engineers, please tell me why bigger throttle bodies is a waste of time, on NA.

 

People have done it and the difference was negligible, and if it's not port matched then forget it all together. On a serious engine build I'm sure some improvements would be seen but definately not on a stock engine and DEFINATELY not on a stock NA.

As someone already posted, read

http://twinturbo.net/net/viewmsg.aspx?forum=main&msg_id=931443

If you put a larger throttlebody on the plenum and use the factory intake piping, you aren't really doing all that much for the system as a whole, so if you do decide to go to 60mm throttlebodies, it would be strongly suggested to also go to larger intake plumbing as well. This, of course, will make your work to make this a complete mod more time consuming and expensive, but if you aren't upgrading the pipes, this mod will have little effect.

 

Well the larger diameter would reduce gas velocity which could reduce response and low down torque. But on the upside the restrictions higher in the rev range would be reduced. I suppose it all comes to a trade off?

 

I think most people over estimate the benefits of this mod to be honest, I'll quote J4Play because he's right on the money here.

By all means go and do it, but get it on the dyno before and after so you can really see how little this mod improves power by itself on a stock motor.

 

yup, and anyway, who wants to make peak power at 3000rpm ? hehehe

We'll see guys, as usual, alot of NA haters. Seems like hardly of you guys know what they can do when tuned well..

vg30de IMO is a top engine to work on N/A wise, and im sure after reading around on here Chrispy can re-assure this. I'm in the process of talking to james about a full NA build, although his funds may keep him out of it.

I've been working on my NA project for well over a year now and it's going well.

Any breathing done to help the engine is a good gain..whatever it is, even if the plenum can only flow say x CFM, the TB will never match it, due to the dispersion + plenum holdings. If larger TB's were stupid, why are ITB's done ?

My ITB setup is 48% larger in cross sectional area, is that a bad thing ? we'll see what happens.

Now saying what i've said, it may be a pretty pointless modification on the Z, although it's basically being done for free so meh, it's just a learning experiance for james

although im going to talk to him about this as funds towards a decent intake setup would be better

 

To put it as kindly as possible, NAs are slow and it's as simple as that. It's not about "hating" them, it's about being realistic. You could spend $10,000+ on an NA and you STILL wont make more power than mildly modified turbocharged Z car. Dont believe me? Go and do it yourself and you'll see, it's the 100 million dollar question on every Z forum "how can I make my NA fast" and the best answer is always "turbocharge it" lol

Search anywhere and ask anyone, this mod is NOT worthwhile on an NA and the benefits are negligible even on a TT not to mention having been discussed to death 1,000 times.

http://300zxclub.com/showpost.php?p=122195&postcount=4

http://twinturbo.net/net/viewmsg.aspx?forum=general&msg_id=1717756

With some head work it could be slightly beneficial in the top end but not on a stock engine...

 

I completely agree with you 300ZXT (wow, never thought I would say that ) But for some it's not about having a fast turbo car. Nothing says I'm dedicated like a properly modified fast NA. I love turbo cars, huge amount of fun, but there are very few fast NA's and I want to be a little different. We know where never gonna beat a modded turbo car with the same displacement, it would be foolish to argue otherwise.


If larger throttles can net a gain of 5kW it's worth doing and I am interested to see the results. Would probably be a waste of time on a TT as most have already said, but with NA's you have to take whatever gains you can get.

 

5kw is extremely optimistic, it would be more in the region of 1-3kw for an NA if that and ONLY if it's port matched. I totally understand where all the NA fanboys come from, that's why I'm polite about it. My first Z was an NA and I must say nothing felt slower after I got my first turbo car. It does suck when you've just bought a new car, in some cases your very first car, and you want to make it fast and everyone tells you that you cant because it's an NA. Trust me I've heard it all lol

With that said I have a friend who thinks just like you, he wants an NA just to have and see what sort of power he can make all motor which I completely respect. The problem comes when some NA guys are just totally ignorant to the fact that a NA motor is just not economical to modifiy dollar per hp when compared to a turbo. It's not any one person's opinion it is pure fact. Aslong as you have a clear head about your goals and that they're realistic then you're golden. It's this whole "zomg NA haters suck" attitude which is really lame. Most people who state these things regarding NA's have been in the same shoes as them once upon a time and know how much shit costs to make power without hairdryers.

 

poor buggers

N/A's are copping it latley