majordan

Has anyone had thier TB bored? and if so, what are the advantages and disadvantages of having it done. I was seriously thinking about having it
done but I wanted to get some feedback from the org.

tks,

Jay

Wiking

VG -or- VE?

Having more airflow has the disadvantage of a chance to more fuel consumption, faster rubber wear, noise, shorter 0-60 time... and whatever is related to having more pwr...

When flow in a channel expands, flow slows at that point. Does it cause here any problems? I think not. But dont believe me... The stock TB is heated: will non heated TB start to collect ICE?

To maximize the mentioned 'waste'-effect, the whole system from start of input to exhauts exit tip, should be in balance. The most restricted system part will still define the max flow. Also 'too fast flow' means that nonburned mixture might be blown directly to exhaust during ventile overlapping, which is not desirable... But what do ? I know: zillion pages of performance tuning is all over the net...

After testing that, YOU tell us...

Poormans tuneup: swiss cheese box...
http://www.cardomain.com/memberpage/748507/2

Cliff Clavin

iTrader: (11)

Several guys have done this themselves or had it done. IIRC, MrGone did his himself and noticed better throttle response. Aaron92SE also did his and he might have seen a slight gain in his 1/4 mile time. It has been a while since I looked at all of his information. He is really good about seeing what mods help his car in the 1/4 mile.

I have a spare TB and one of these days (add it to my very long list of things to do) I will have it ported and then the intake matched.

There is a guy somewhere that does really good work (I think mtcookson found it) but I lost the link.

majordan

I have a VG and I think the site in Maxbore.com. His work looks really good.
He quoted me $150.00.

Jay

mtnbikeair

iTrader: (4)

I know matt made a Blehmco throttle body spacer, what does that do?, while we are kinda on the subject.

Wiking

Nice site and good pics. Job done like that, will most certainly work; no change in hose attachments. The plenum and upper intake have then to be fitted with the bored TB. Intake area increases 10-15% (??).

The question is how much actual flow is increased (tube widens = airspeed decreases).

Mizeree_X

iTrader: (9)

I was under the impression VG throttle bodies had a unique shape and weren't easily bored out. Correct me if I am wrong.

Wiking

Its easy to answer when NO knowledge of machining: VG TB has two straight holes - not the common 'std' one hole TB. I guess it needs ? just adjustable boring bench... Double work.

Aaron92SE

iTrader: (128)

Actually, I recently had my TB bored by this guy. Since I was the first Maxima TB he has done, he charged me $100. But after he realized it is much harder to rebuild than a Honda TB, he is now charging $150 for Nissan TBs.

I can not recommend maxbore to anybody on here just for the sheer fact that his customer service is below average. He is not professional in his emails and his lack of communication had me worrying about my item. Also, he installed my TB pin 180 degrees the wrong way, so my TPS is upside down!! That REALLY pissed me off. I am satisfied with the actual quality of the bore. Looks great. But, I will not go through this headache again. There are many other companies that can bore your TB for $150. Look into ASP or any performance machine shop around the country. You might have to rebuild it yourself to save a few bucks, but it IS an easy process. I've removed the pin myself with a simple hammer. I don't know what the fuss was about with this guy at Maxbore.

But all in all, my TB was bored as much as he could safely bore and my 60mm plate was replaced with a 63.5mm plate. I can't tell a difference in throttle response over my ported TB I had before. But I also did a lot of other work to my car in the process. I installed a TB teflon spacer, Upper intake teflon spacer, a new injector, rebuilt VTCs, and a variable intake system from a VE 5spd. But here's some little advice, get Teflon/Phenolic spacers!!! They work! You will gain some noticable low end power and your upper intake manifold will be cool to the touch! Nobody makes them right now other than BlehmCo, but if you decide to make your own from a sheet of teflon, you will not regret it! Just keep in mind that the most noticable will be a spacer for the upper intake manifold between the Lower and Upper IM.

mtnbikeair

iTrader: (4)

What does the spacer do? And how much does Matt charge for that?

Wiking

Adds value to teflon sheet; creates income for seller.

If one wants TB not heated, just add bypass valve for the heating water circulation hoses [at the arrow pointing left to the TB]...

Aaron92SE

iTrader: (128)

Haha, true, that will help. But if you seperate the lower from the upper IM with a heat resistant spacer, you will get rid of 90% of the heat transfer. Your upper intake will stay VERY cool, while your lower IM is over 180 degrees. Phenolic/Teflon spacers have been proven to work.

Wiking

"proven to work"
- can you define that in detail.

Colder intake/air is always better. Still does not really affect airtemp while full open throttle. Then airspeed nears supersonic speeds and only huge surface area intercooler can have an effect.

Mizeree_X

iTrader: (9)

That's disappointing about Maxbore. I was planning to send my spare TB / IM to him for some work. When did you send your TB to him? When FL was hit with all those hurricanes he kinda shut down for awhile but it looks like he's back up and running. Would it help if I shipped the TB already dissasembled?

Aaron92SE

iTrader: (128)

I think it would help if you disassembled it. He's probably bore it for $100 if you take it apart for him. He bored my TB around Christmas weekend. So he was definitely back up and running at the time.

Wiking, anytime that your IM is cooler, you will make more HP. Why do you think icing the IM at the track helps so much with track times? The intake air temp will increase dramatically when the IM is 180 degrees. But it won't increase nearly as fast if the IM is 100 degrees. Spacers also lengthen the intake path that has been proven to work in raising a carbuerator. But, as for as lengthening the intake path on the Maxima, I instantly noticed better low end power and a cold upper IM. Do a little research with other fuel injected cars. You'll find dyno proof that phenolic spacers can give you 6+hp. Search the SR20DE forum, you'll find a lot of good info there about spacers.

mtnbikeair

iTrader: (4)

How much do the spacers cost???????

Wiking

1 dremel + 5$ piece of plasTics

Aaron92SE

iTrader: (128)

Actually, it's a dremel plus a $35 sheet of plastic. You have to make sure you get a sheet that can handle the temperatures you are going to subject it to. Phenolics, Delrin, Teflon are all great choices.

Ask Matt about the price of his spacer.

Wiking

Anytime air is cooler = more hp.

"anytime that your IM is cooler more HP"
True ONLY on low airflow. Icing? helps on the start, few first feet.

"at the track helps so much with track times?"
How much it helps? Have actual measurements been done with/without that magiplastic? Such measurement that REALLY can be comparable, without feelings? I will believe if such 'scientific' study has been made. ...Not that it matters what I think

Of course at idle the air temp iside intake is about same as upper intake. But pls measure that temp at full throttle: I think the difference is minuscle, even unmeasurable. If it was, why ? people use intercoolers...

The real problem is lower intake and its stupido overheating construction. Block that heaterflow...

Aaron92SE

iTrader: (128)

I'm sorry. I'm not understanding what you're saying. If you don't believe the concept, it's cool. You don't have to run out and get a spacer. Do a little research on spacers used in other cars and you will find dyno proof. Anytime you decrease the temp of your IM, you WILL gain HP. Yes, even at WOT. Air still has to flow through the upper IM. Imagine the upper IM being a billion degrees. Even if air flow through it for a fraction of a second, it's going to heat that air up.

This spacer won't give you break neck speed. But I've seen more than one dyno where 4 bangers and v8s have gain more than 5hp from this modification.

DanNY

iTrader: (14)

http://forums.maxima.org/showthread....2&page=2&pp=40

looks like matt said $40 for the VE TB spacers....best to double check w/ him.

Wiking

That is not dangerous ...and goes both ways.

But I think we both agree on air temp.

FULL throttle:
Are you saying intercoolers are waste? T-here exists some serious COOL square meters which will be 'touching' almost all air molecules on their way to big bang. Intake tube does never come zillionth inch near that, so its temp effect will always be minuscle compared to intercooler. Well, maybe its measurable as u insist on it. Still want to see that fact myself.

I have to admit that I've no actual play experience racing with ice - only racing ON ice. No dyno experince either... Here is one interestincooling link of serious business to cool down that bit wee agree on:
http://www.are.com.au/techtalk/intecoolersMR.htm

Bill Brasky

iTrader: (2)

this thread makes me keekle....

i have no coolant diversion or anything like that. After a 20 mile jaunt on the freeway to jeffies, my TB and TB elbow was still very cool. Go-Go CAI V2.0

Wiking

Key words: "on the freeway". Dont mix up all to u soup. Mind u, Alle Wagen kommen mit CAI as stock.

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

What IS MISSING - FACTS in this discussion = measured TABLE which shows air tempS inside various points in the intake.

1. One TABLE with plasTics on,
1. One TABLE with plasTics OFF.

Both tables with same ambient temp, same settings, same engine, different rpms, 1000/2000/3000/4000/5000 ....each test five minutes.

As smbdy shows that, facts come in, feelings fade... It might be nice to say 6hp more - without really knowing where hp comes from. If such tables exist, pls show where... Smbdy who sells these, has made such testings. Where is this info, or has it been hidden because of not so nice results? And if smbdy sells and has NOT made basic research, I would not put my money on T HAT...

Aaron92SE

iTrader: (128)

What do intercoolers have anything to do with what we are talking about? I never said intercoolers are a waste. I never even slightly hinted at that point. Go get a piece of phenolic plastic, put it on a hot burner, touch one side of it, then touch the other side. You'll see that it blocks most of the heat from making it to the other side. This keeps the Upper IM much cooler. Anytime your manifold is cooler, you WILL make more HP. Air does get heated up much more passing through a hot IM than a cool IM. If you still doubt me, then I don't know what else to tell you. Go do some research on phenolic spacers. You will find a crap load of dyno proof and temperature measurements for other cars.

internetautomar

iTrader: (30)

hey, if you put a peltier junction in there you could make some electricity while you are at it

Wiking

All = ALL. The question is:
1. airspeed (=here also volume)
2. contact area
3. contact temp

Only intercooler area has the capacity to cool fast flowing air - to be meaninful. This is simple math. Upper intake contact area maybe 1/100 of intercooler, dunno really. (Slow speed is another story)

Maybe I am lazy... but as u are so sure of this, u should have the facts.
Lets pass by this issue, world does not stop if I dont believe... actually nothing is affected by that But. Happen to have been testing heat conduction in industrial solutions, thats why its hard for my hat to get without numbers.

Wiking

PeltIers: Actually I was disgusted at peltiers: They need huge transformers which are waste, peltiers last one year and then rust away. My project luckily got away from them, and we started to using vortexes.

Aaron92SE

iTrader: (128)

An intercooler can cool much better than an equally cool IM. I am not comparing this to an intercooler. You are lazy. You are quick to say a spacer is a waste of money, but you won't do any meaningful research on the matter. I am not going to spend an hour on digging up dynos and air temp figures just to continue to argue this point. A spacer might only cool the air temp by 5-10 degrees, where as an intercooler can cool it by 30+ degrees. But anytime you have any kind of intake temp drop, it's worth it.

Wiking

Yes. Me plain lazy naysayer. Need BIGger horses. Or your footwork.

One problem playing with dyno, that dyno itself does not produce scientific measurements that I am after [=repeatable]... there are million details to be fulfilled to create exact repeated testing rounds taking care of all possible variables. To go through all those, would be huge undertaking.

About nothin: After me found out that world does not revolve around me, life became easier for me. Nowadays me finds out that me can be even lazy, stupid and ridiculous; somebody else seems to take care of tHis world...