Supercharged And Tbs

[hcmini1989 16]

right i just have a quick question i plan on putting tbs on my mi16 engine and eventually supercharge it .my problem is with me fitting the supercharger i will probably have to make some sort of planumb chamber to feed the air into the tb`s from the charger .so wouldnt this restirct the air going through the tb`s thanks for any advice

Edited October 13, 2009 by hcmini1989

[EdCherry 34 1 Cars]

Think your main issue is space really...

[hcmini1989 16]

Think your main issue is space really...

thats not gona be an issue .well shouldnt be provided a drop the rad and dont use any trumpets just go straight onto the back of the tbs .just curious to see if anyone knows wheather it would be pointless in fitting the tbs as they would be restricted by the new plenumb

[EdCherry 34 1 Cars]

Plenum design is a long and extensive topic, hard to get gains, often you reduce power. I wouldn't be worried about this though as you arn't using trumpet's... Looked into the trumpet design yet? cause I certainly would be now.

[rapidcossie 0]

just make sure the trumpets are strong enough to take the boost pressure as some of the very thin light weight alloy spun ones can fail under higher boost pressure

[hcmini1989 16]

Plenum design is a long and extensive topic, hard to get gains, often you reduce power. I wouldn't be worried about this though as you arn't using trumpet's... Looked into the trumpet design yet? cause I certainly would be now.

huh? im not going to use trumpets straight off the back of the tbs to the charger so it wont really be a plenum just a pipe to feed the tbs with air .

 

the idea i have is to do it similar to the design of a fuel rail.one big pipe with four outlets for the tbs .trying to keep it simple as possible

Edited October 13, 2009 by hcmini1989

[EdCherry 34 1 Cars]

More than a few things I dont get about the build already...

 

What do you want to gain by using the TB's?

 

Why go to all the effort of mounting everything but missing out the MAJOR details, the small things that effect the power in a big way?

 

Id sit down and figure out what you really want cause at the moment all I see is a mish mash of dreams, hate to put a damper on it but id rather be blunt.

 

I hate to be negative so heres a bit of positive...

 

If you can mount it all together then id start looking at something like a shorter inlet manifold rather than reducing the trumpet length. The trumpets are controlling the airflow path into the throttle bodies which is pretty important. It needs to have a nice radius on it to draw in the air, in a N/A application anyway.

 

You could surround the trumpets in a Plenum, not sure how much the design will matter with forced induction as the atmospheric pressure is positive in it because of the charger, rather than trying to design the airbox/plenum to make a positive pressure. Going back to your original question if your using the same diameter as the outlet of the charger continously (piping and plenum opening) then you shouldn't be restricting it in any way.

Edited October 13, 2009 by EdCherry

[hcmini1989 16]

More than a few things I dont get about the build already...

 

What do you want to gain by using the TB's?

 

Why go to all the effort of mounting everything but missing out the MAJOR details, the small things that effect the power in a big way?

 

Id sit down and figure out what you really want cause at the moment all I see is a mish mash of dreams, hate to put a damper on it but id rather be blunt.

because i already have the bodies manifold + ecu ready to go on .and i will be picking a charger up on saturday morning hopefully .why do people use tbs in the first place only reason i can see is to let more air in than standard one.or why else use them im not sure ?

 

but if all tbs are being fed from the same air supply in my case a pipe coming from the charger .do you think it would restrict the air going to the tbs .

there fore be better off being standard just one throttle body

 

allso when you say missing out the small things what do you mean

thanks for advice

Edited October 13, 2009 by hcmini1989

[EdCherry 34 1 Cars]

Personally I think it might be worth your while selling the TB's when it comes to it to fund the SC, not sure you'd gain that much from running both, or infact lose/gain much removing them other than a healthier bank balance.

[Galifrey 1]

Personally I think it might be worth your while selling the TB's when it comes to it to fund the SC, not sure you'd gain that much from running both, or infact lose/gain much removing them other than a healthier bank balance.

 

I just wrote a huge post explaining why this would be the best course of action, and lost it when my browser locked up, basic gist was that what you gain from ITB's you are already exceeding with the supercharger, so sell them and dont complicate matters.

[hcmini1989 16]

thats all i wanted to know thanks alot for the advice

Edited October 13, 2009 by hcmini1989

[paul205mi16 4]

Im interested to see your ideas on mounting the charger and how you will power the charger. Bit of planning and frabrication work needed. If I had more time I too would like to supercharge one of my Mi16 engines. good luck.

[dcc 855]

I think the advice here is very opinion lead, and I would beg to differ some of the responses - If he has the time, money and patience.

 

I have seen a gti6 run with bodies and a turbo aswell as an 8v with tb's and a charger. Both cars produced silly power. You are looking at getting what a car with tb's gains over a standard engine, but with alot more performance increase. I think if you can put up with the build then go for it, would be very impressive to see what you can come up with. From memory, the airfeed for the trumpets on the 2 I had seen was VERY robust, possibly 3-4mm thick or some sort of metal.

 

from memory the gti6 was boasting about 300 ftlb of torque. I have a feeling it might have been built to a high spec, maybe a 2.1

[welshpug 1,675]

there's a few factory engines I know of with ITB's and boost, notably the Pulsar/Sunny GTi-R's SR20DET, and the R26DETT skyline engine, these are Direct to head type (afaik, or a VERY short manifold if they do have one) so are pretty short, never seen one up close so I don't know what type of plenum they use, they're also engines that sit bolt upright so they don't have the issue that the XU's do of anything bolted directly to the head pointing straight at/through the bonnet.

Edited October 15, 2009 by welshpug

[Galifrey 1]

I think the advice here is very opinion lead.

 

Agreed...

 

It is perfectly viable to use boost and bodies, but it is way more complicated. If you are looking for really big power, and are replacing the internals etc, then it is almost definitely worth considering.

 

As its perfectly viable for 500+bhp from a single body tho, is it worth the fuss?

 

Like you correctly state, its an opinion (read my sig for disclaimer)

 

 

http://cgi.ebay.co.uk/Nissan-Pulsar-Sunny-...emZ140351954790 good pic of some GTIR boddies and plenum there, I think what you can't see is the inlet sandwich plate between head and bodies. About 20-30mm IIRC

[hcmini1989 16]

will get some pics up on a project thread soon as i get the charger and hopefully it will fit

[DrSarty 99 1 Cars]

Pulsar bodies are direct to head.

 

The inlet plenum and other pics below show how it all works. But as said the SR20DET engine sits bolt upright, and like a TU engine the inlet is on the bulkhead side.

 

Edited October 15, 2009 by DrSarty

[Galifrey 1]

Pulsar bodies are direct to head.

 

Yup, think you are spot on mate, I think I was getting confused with the RB26 which uses much thinner bodies and has a sandwich plate with the coolant running thru it.

[sideways danny 0]

there's more to individual throttle bodies than just letting more air in. The distance from the throttle to the back of the valve is dramatically reduced, and this give you far quicker response. It's important to use trumpets, or atleast a tapered lead in. Air is drawn in from the side not the front. trumpets steer the air in. Jenvey make a plenum to bolt to ITBs and fit trumpets inside

[DrSarty 99 1 Cars]

GTI6 plenums have nice trumpets inside, which is one of a few reasons why they're a better design.

[Galifrey 1]

there's more to individual throttle bodies than just letting more air in. The distance from the throttle to the back of the valve is dramatically reduced, and this give you far quicker response. It's important to use trumpets, or atleast a tapered lead in. Air is drawn in from the side not the front. trumpets steer the air in. Jenvey make a plenum to bolt to ITBs and fit trumpets inside

 

The quicker response is a nice to have for a racecar, but can make it a pig to drive on the road with the engine becoming like an on off switch. Trumpets/Taper is important but the length isn't as important as a normally aspirated engine as the charger is already increasing the VE, so you can use a far shorter induction tract.

 

The Jenvey plenum can be used with ITB's or a single TB and a shorter inlet tract/manifold

[sideways danny 0]

if it's like an on/off switch you've gone too big on the butterflys normally. That or the mapping isn't right

[Galifrey 1]

if it's like an on/off switch you've gone too big on the butterflys normally. That or the mapping isn't right

 

Sorry, what I mean is, in traffic it can be very kangaroo inducing, with tiny movements of the foot...

 

You have promoted the positives of ITB's we have just balanced it with some negatives in context. If you want to build a no-expense spared engine go with the ITB's as well as a supercharger by all means, but with the supercharger, not having to worry about turbo lag, the reponse of a single throttle body is going to be pretty adequate for most, saving a lot of money.

 

One of the best installs I saw had a handmade plenum bolted direct to head with centre mounted injectors spraying straight into the inlets. For most people, sandcasting and machining a plenum is a bit much tho.

 

[sideways danny 0]

kangarooing is more down to big changes in ignition timing though what idle control strategy have you been using?

 

I wouldn't actually promote using ITBs aswell as charging normally, just trying to balance the discussion as the understanding of what they do seemed a little limited

Edited October 16, 2009 by sideways danny

[Galifrey 1]

kangarooing is more down to big changes in ignition timing though what idle control strategy have you been using?

 

I wouldn't actually promote using ITBs aswell as charging normally, just trying to balance the discussion as the understanding of what they do seemed a little limited

 

My experience comes from an engine with standard ITB's, I used its stock idle control strategy