What sort of power could i be looking at running a Vauxhall 2l XE engine with GSXR1000/1300 throttle bodies and a Megasquirt?

Assuming stock engine internals.

Rob

I've heard of 180 on Carbs and 200 on Throttle Bodies from a good source.. possibly on here, all with stock internals.

Ive got a standard although blue printed and balanced XE in my formula vauxhall lotus and with twin 45's it showed 200bhp on th rolling road, with single point bosch injection it showed 185 bhp,

I was talking to "scotlad" this week and he reckoned that with TB's it may push about 220bhp if set up correctly i would agree with this as TB's usually give an increase in bhp over carbs.

cheers

Andy

I'm hoping for around 200 with the std engine and gsxr1000 bodies with a squirt.

I'm liking the sound of that. 200bhp would be just what i'm after. Has anyone got a price for the bell housing to mate these to the type 9 gearbox?

Thanks

Around the £150 mark from various places like yukspeed SBD Aframe engineering etc.

Or 256quid from westfield..

I cant believe how much some of the stuff is in their calaloge...

Does anyone do a manifold to fit bike TB's to the XE

If so who and how much?

Im looking to upgrade mine for next season

http://throttle-bodies.com/shop/product_info.php?cPath=22_23&products_id=88

They also do the spacer kit to line it all up.

Rob

[Edited on 8/9/07 by Mr Rob]

Thanks for the link.

Doesn't look too expensive.

Are bike TB's as good as the like of jenvey TB's that are specifically for car engines ?

Bike TBs would be smaller diameter i'd have thought so they may have restricions but there is no way i'd spend 1500quid on car bodies.

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Originally posted by Mr Rob
What sort of power could i be looking at running a Vauxhall 2l XE engine with GSXR1000/1300 throttle bodies and a Megasquirt?

Rob

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As for inlet, mine is an all alloy effort like the above link, straight runners, (GSXR TB's can be spaced to fit as they are in essence 4 separate TBs, bit of jiggery with the fuel rails, but not too tough work)




I've spent about 4 hours with the dremel carefully removing all the sharp edges and contouring them and making sure the inside of the runners was rough / smooth enough for good flow. Probably make 0.001% difference, but it was a free mod!

They are machined properly from solid bar to go from the round inlet runner to the inlet port shape on the XE head rather than just squashing a tube oval as others do.




Obviously that's a before picture..

Nice machining work though.

Size isn't an issue for bike tb's, GSXR750/1000 ones are around 42mm depending on year (01/02 ones are 48 tapering to 42 for example) which is plenty for most 2.0L engines. There are bigger bike bodies than that as well (e.g. 'busa).

One thing that isn't as good as a set of proper car bodies is the closed throttle plate angle, it's quite high on bike bodies (i.e. when closed the butterflies are closer to being perpendicular to the wall of the body on a car than they are on bike ones). This means that a small change in initial throttle angle produces a much bigger change in airflow, so they can be a bit 'peaky' coming off idle. Suzuki use stepper motor controlled secondary throttles to smooth the off-idle transition, with quite a funky control algorithm. I'm sure a determined locoster could do something about it if it was really getting on their tits, like making the throttle butterflies more circular so they'd close further, but tbh most people probably won't care that much...

I haven't had a problem, but then the usual mode is launching from 4.5k and not dropping off the throttle much till the last lap.

Interesting though, it could explain the difficulty I've had in tuning the accelerator enrichment, it does 'lean out' very easily at small openings from idle even using the TPS to control enrichment, there's a definate small 'lag'

No issue in a racer, but could be annoying at the lights etc..

My secondary butterflys have been removed and the holes sealed with epoxy.

[Edited on 8/9/07 by GregSL75]

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Originally posted by GregSL75
They are machined properly from solid bar to go from the round inlet runner to the inlet port shape on the XE head rather than just squashing a tube oval as others do.

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But if you look at the XE port shape:




It's not oval

Hmm, that's precisely my concern about the less expensive manifolds for my Zetec. An ovalised tube doesn't match that shape, especially the shape for the injector. The less expensive manifolds seem to ignore this. The expensive ones (Altiss) do it like this one, with machined tubes. But than, an Altiss manifold (including spaced GSX TB's) is 650 pounds.

Well, you get what you pay for of course. But my main concern is: how much would it hinder performance if it's just a "squashed" tube?

I've seen a couple of installs on VW 16v heads where they've gone the other way, the injector cutout in the head itself has been welded up to make an oval port to match a weber manifold.

I don't think it'll make that much of a difference to be honest, bear in mind there's normally an injector filling up that space anyway. The step is the right way around so that it won't impede flow terribly, you might see a small effect due to a change in flow speed as the diameter changes. If you can match the shapes without too much trouble then you may as well, but I wouldn't lose too much sleep over it otherwise.

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how much would it hinder performance if it's just a "squashed" tube?

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quote:

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Originally posted by GregSL75
But if you look at the XE port shape:
It's not oval

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Heh, that'll be my shop then

The injector cutout not being present is no a hinderance to a bike TB manifold. As stated, it's only there to clear the injectors spray cone on the stock manifold as it's so close to the head flange/face.

Altiss' solution is very nice, but waaaaaaaay overkill for the sort of installation at hand - bike TBs are meant to be a cheaper alternative!

Well, I noticed that Weber manifolds also ignore the injector cut-out, while it would have been very easy for them to add them to the casting. So I figure they also concluded that the effect was negligable.

And I remembered seeing some standard Zetec manifolds where huge chunks of casting seemed to be missing in the ports. And apparently passed quality control and made it onto the engine, which probably didn't suffer from it either.

So I'm probably just worrying too much. Although I must say that the machined runners do look yummy.

For 650 clams, I'd expect a fu**ing blow job...

I'd say 200 was a fair estimate then!

Up from 170.4 on the first run. The whole map is dialled in spot on now and the throttle response is transformed. Money well spent, can't think of a cheaper way to make an extra 30bhp in a few hours!

Can GSXR throttle bodies be run on a standard injection ecu or do i need to upgrade to a megasquirt ?

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Originally posted by andyw7de
Can GSXR throttle bodies be run on a standard injection ecu or do i need to upgrade to a megasquirt ?

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