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Old 19th July 2007
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Default Throttle body per intake runner setup

i've been mulling over what to do to the 8v for a bit and i think i'm reletively sure now, i'm currently looking at motorcycle throttle bodies as i want to run individual TB's.

I'll be using 38mm diameter aluminium tube welded to the flange which will have about 2 inches of the origional runners left so i can mill them out and get a smooth transition between the round inlet runners and the square valve entrances.

I can't decide what sized TB's to get, i was thinking of oversizing them slightly to take into account the throttle plate and spindle reducing flow, so at the moment 42mm seems best.

I know Sonett1 has some 48mm jenvey throttle bodies and a very nice cast alloy manifold, but i think in my set-up the step down from 48-38 maybe a little to steep, his is a n/a application so slightly different.

Anyone able to offer thoughts on whether i should match the intake tube diameter or go oversized, if so how much?
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Old 19th July 2007
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Here's an thread on the subject from another site:

http://www.saabrally.com/forums/view...er=asc&start=0
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Old 19th July 2007
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Besides the size of the TB you also need to take into account the distance of the TB plate from the intake valve/port. You can "tune" torque this way, and its resulting impact on power. See http://www.team-integra.net/sections...?ArticleID=471. I have a spare intake manifold for my T16, which I shall shorten this winter, to increase the rpms of my "peak" torque (in theory).

pierre
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Old 19th July 2007
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I've just found a link in the thread TRB linked (cheers), there is a company in the UK that does the inlet manifolds, and for a price i can justify spending .

Would be interested to hear from anyone who has used the company or product.

http://www.rallydesign.co.uk/catalog...ducts_id=11401
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Old 20th July 2007
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Here's a few pic's of a certain Sweed's 99, will be doing something like this, with an integrated chargecooler plemum, can't figure out from the pic's where the TB is though .

Alot of Zetec tuners use Suzuki TB's for turbo conversions so i'm going with that option. Pic's stolen from BIRDYMANGO or maybe Ejenner/Philb, not sure who took the origionals!

Decided on using 45mm TB's to start with as the inlet diameter of the manifold linked above is 45mm(i think!), probably off a Suzuki GSXR1000.





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Old 20th July 2007
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I think those are birdiemangos photos. Its impossible to see the TB, but I can see 2 linkages in the first photo. Look between injectors 2 and 3. Are those 2 throttle cables, working on a set of throttle bodies right beside the cylinder head? That would make for better throttle response anyway.
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Old 23rd July 2007
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It's funny actually. Throttle response seems a bit slow on a T16 but great on an 8v n/a... And as the intake setup is fairly similar that leads me to believe the sluggish throttle pick-up on a T16 is down to the engine management? Obviously on an 8v there is no engine management because it is mechanical injection. Not sure if I'm right or not.
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Old 23rd July 2007
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Its interesting alright. My parts car is an n/a 16v, it seems to have better throttle response than a t16 also. Its got even more electronics than a t16 though, I think in its case, the optimized timing helps further. I'd say the response issue is mostly a mechanical one.
Aside from slightly lower compression + turbo lag, is it possible that the turbo's compressor causes a significant restriction in the intake, until it spins up?
I'm thinking the delay is in getting the air in, not the fuel. The ecu can react quick enough to add fuel in.
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Old 23rd July 2007
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I have idly pondered whether having a second filter with a large throttle plate on which opens at vacuum/low boost then closes as the turbo starts to spool would be of benefit, as everything i'm adding to the car is really for high reving boost i need to figure out how to get the turbo to spool as low as possible, and get as much power off boost as possible, apart from making it driveable at lower revs i also wondered if it would help with spool up.


Am i right in thinking that the more power you make off boost the earlier the turbo will spool?
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Old 23rd July 2007
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pretty much, since more power = more exhaust gas. Optimized ignition timing would help here. A vnt turbo also helps the spoolup. Or you could run e85, and higher compression.

I was just thinking the same thing about a second air filter, but its only a valid option if, indeed, the compressor is a restriction off boost.
You'd need to be running a map sensor, not an air mass meter, but I'd say it could be made to work.
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Old 23rd July 2007
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Just debating whether it's time to order MS or leave it for another few months, would'nt be a prob them as it's MAP/MAF & IAT .
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Old 23rd July 2007
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MS supports map right now, whats the problem? Get it now, stop spending money on that vectra!
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Old 23rd July 2007
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Maybe but i need a shed reletively desparately, partly so i've got somewhere to make noise cutting and welding, and partly to get my tools out of the house, i seem to have built up quite a collection of tools/powertools and various machinery, so much so i can't actually fit it all in the house! I've had the desktop milling machine sitting in the living room since i bought it in November .

I also need to be reletively sure about the set-up as you can pay a bit extra for stuff like boost control & 5th injectors etc.

Trigger wheel or Hall sensor or both and do sequencial injection?

EDIS or go with uprated coil & dizzy?

Do i want any other controllers? 5th injector/WI - i've got the solenoid valves already, just can't decide if i actually need them, may go for a tolulene injector.

Boost contoller - use MS to detect Knock or APC? Should the APC trigger MS boost controller?

ITB's i think it needs to be set-up partic for itbs rather than a single TB

Do i want MS to control the chargecooler pump and have a temp sender input?

If i move over to an Electric water pump (coolant) MS controlled or separate controller?

Anti lag system maybe?

Can you run atmos dump valve or recirc?

All stuff i don't know or can't decide on.
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Old 23rd July 2007
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Quote:
Originally Posted by Si
I have idly pondered whether having a second filter with a large throttle plate on which opens at vacuum/low boost then closes as the turbo starts to spool would be of benefit, as everything i'm adding to the car is really for high reving boost i need to figure out how to get the turbo to spool as low as possible, and get as much power off boost as possible, apart from making it driveable at lower revs i also wondered if it would help with spool up.


Am i right in thinking that the more power you make off boost the earlier the turbo will spool?
A turbo engine and a N/A engine are much the same as regards flow, the only difference is that the turbo is using a higher pressure. All things being equal their requirement for increased flow is much the same.
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Old 23rd July 2007
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Throttle lag - the time between opening the throttle plate and air passing through it into the engine. On an N/A car it only has to go via a short pipe - on a turbo car it has to travel to the turbo, get compressed and travel through an IC which is probably 4 or 5x the distance - hence why N/A cars feel more responsive. Turbo lag - the time taken for the turbine wheel to get to a speed where it is pressurising the air sufficiently to creat power. Inertia due to rotational mass and friction in the bearings being the important limiting factors. Put together and you can have a seriously frustrating driving experience. Search for some pictures of the old 99T rally car if you want a turbo car with quick throttle response (and a project for your tools Si) - turbo mounted above and in the middle of the exhaust manifold delivering boost via a pipe that went over the cam cover, between the runners and into a central throttle. Obviously no IC but then they used water injection. It looks like they used a big turbo for high RPM power so it must have taken a while to get it up to power but once there you would use all the race drivers tricks of keeping the revs up and would have had near instant throttle response for optimal power balancing when throwing it around. Maybe not an ideal road car but witth a smaller turbo it may be OK.
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Old 23rd July 2007
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Anyone hazzard a guess at the % loss in power is from the lower compression ratio of turbo engines (off boost)?

8v's are 7.5:1 ar'nt they?
As long as there's enough power off boost to pull through the corners having the turbo spooling later should'nt be a problem, you just have to adopt a driving style to compensate, not having a huge amount of torque may actually make the car a little more stable comming out of the apex aswell, a big gob of torque would probably unsettle it to a certain extent.
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Old 23rd July 2007
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Quote:
Originally Posted by Si
I've just found a link in the thread TRB linked (cheers), there is a company in the UK that does the inlet manifolds, and for a price i can justify spending .

Would be interested to hear from anyone who has used the company or product.

http://www.rallydesign.co.uk/catalog...ducts_id=11401
The mangoletsi and chadil manifolds are probably the worst 99 DCOE manifolds ever made!
Have a read through this thread http://www.uksaabs.co.uk/viewtopic.php?t=16899&start=15
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Old 23rd July 2007
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I'd already decided to go with the Swedish one, and then changed my mind again back to altering the stock manifold .

Spent a couple of days looking at TB's and realistically if I go with the MISAB DCOE manifold i'd have to get the Jenvey TB's as they seem to be the best availiable, price & quality wise. But that all adds up to over 600.

Alternative is some GSXR1000 tb's and then cut and mill the stock manifold, weld some new runners in to match the GSXR's, then use hose connectors to join them, the sticking point is although it's more work and no way as nice solution, but i can do it for 300, i could make the intake path reletively smooth aswell.

If i go with the motorcycle tb's i can also start looking at putting together the exhaust header, just need to find someone to cut me a 8v exhaust flange, if i don't get my milling machine set-up in the mean time.
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Old 24th July 2007
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Misab no longer make the manifold for the 99, they do come up from time to time though, the next best is the MSS manifold, this is still available.
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Old 24th July 2007
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Quote:
Originally Posted by Shirozina
Throttle lag - the time between opening the throttle plate and air passing through it into the engine. On an N/A car it only has to go via a short pipe - on a turbo car it has to travel to the turbo, get compressed and travel through an IC which is probably 4 or 5x the distance - hence why N/A cars feel more responsive.
The throttle on a t16 is in the same place as on an n/a. The difference is pre-throttle. If you fit a longer pre-throttle intake tract to an n/a, why will the throttle response worsen? Surely one of the factors is that a turbo car has the compressor in the intake, getting in the way.
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