Camshaft

[hkspeed]

Hello,

I am mark from holland i have an st202 celica (3s-ge engine with 175 hp stock) i have a hks silent hipower catback with an hks super header type 2 header with decat pipe, exteriour mods are a modest bodykit.

I have already a inlet modifold for the jenvey throttle bodies i am thinking for an autronic ecu, the ports are also gonna be ported.

i am thinking about cams either catcams (catcams.be) or piper cams, but i have never read about experencies of other st202 owners with cams do you have this experience on this forum.

[mikeb]

The rev 3 3s-ge makes peak power at 7000 rpm. I don't know what rpm the bottom end can take in stock form, but would assume not much more. In which case, there's probably not much point changing cams.

Having said that the vvti beams engine made 200 hp @ 7000 rpm in autobox mapping, and 210 hp @ 7600 rpm with the manual gearbox. I don't know if they revised the bottom end to take the higher rpm, but both of those engines ran 11.5:1 compression. Also not sure if the cylinder head was revised (other than the vvti stuff).

It might be worth raising your compression if you want more power, but expect to need high octane fuel to go with it.

[hkspeed]

The rev 3 3s-ge makes peak power at 7000 rpm. I don't know what rpm the bottom end can take in stock form, but would assume not much more. In which case, there's probably not much point changing cams.

I want to extend my powerband instead of 3000 until 7000 rpm, the new from 3500 rpm until 8000 rpm and amor agressive cam does add hp in higher rpm.

conpression comes later first cams, a ported head throttle boedies, this cost already a small fortune.

[daktari]

IMO it would be more beneficial to keep the upper rev limit at 7000 RPM and use a cam profile that will increase torque in the mid range. This is going to have a similar effect as raising peak power to an 8000 limit but without the inherrant danger of losing the bottom end.

Gas flowing will also help if it`s done correctly. And should produce good results in conjunction with uprated throttle bodies and reprofiled cams.

If your determined to raise the rev limit then you obviously need to take adequate precautions with regard to using superior engine lubrication preferably with an uprated oil cooler and pump and shortening the oil change intervals. After all your looking at increasing the revs by 14% which is asking a lot from the standard lubrication system.

[hkspeed]

i see what you meen, a mild cam say 261 degrees with 11mm lift (including a valve train kit ) so that you have a wide powerband with bottem end power.

[daktari]

Indeed. You`ll be getting available power down sooner and for longer which will negate the need to rev out the engine which would possibly take longer to max out anyway. Certainly in the higher gears.

[mikeb]

Does anyone know the cam specs for the standard cams for both the rev2 and rev3 engines? I assume they are different, due to the different power bands.

Bear in mind that if you junk the stock intake manifold for TBs, you loose any advantage of the ACIS, which will narrow your power band before you gain anything. If you are raising the rev limit then fair enough, but the stock induction system seems to be good enough for 7k rpm.

Personally, I doubt that there is much (if anything at all) to be gained by 'porting and polishing'. The head seems to flow pretty well without mods.

Is this engine to go in an all out race car, or is it to be used as road car as well?

[hkspeed]

The head flows indeed pretty good but there is always room for improvement

By port and polyshing the expected gains are 15hp until 30 hp accordingly to a known tuner in Holland.

Although the intake system is good, a throttle body per cilinder is in my opion always better.

The motor stays in my st202 for use as a road car (with semi race specs )

[mikeb]

The head flows indeed pretty good but there is always room for improvement

By port and polyshing the expected gains are 15hp until 30 hp accordingly to a known tuner in Holland.

Although the intake system is good, a throttle body per cilinder is in my opion always better.

The motor stays in my st202 for use as a road car (with semi race specs  )

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15 to 30 hp from a ported and polished head? Not a chance of that, not on any modern engine. ;) A 5hp gain from porting and polishing would be a good result IMHO.

Personally, I wouldn't want to throw away the ACIS of the stock intake on a road car. A full race car where the only concern is peak HP, then yes throttle bodies would achieve it, just at the expense of low end pick up.

[hkspeed]

I have never read about another third gen 3s-ge with a ported head and polished valves so i will go with the experience of the tuner.

With throtle bodies you wil gain torque as well, depands on the size of the throttle bodies self (will you get long or short runners, depands on the powerband you want to create).

I read about a guy in the netherlands with a vauxhall (2.0 16v) 150pk with a group A exhaust, camshafts and throttle bodies he went to 204hp.

[mikeb]

I have never read about another third gen 3s-ge with a ported head and polished valves so i will go with the experience of the tuner.

With throtle bodies you wil gain  torque as well, depands on the size of the throttle bodies self (will you get long or short runners, depands on the powerband you want to create).

I read about a guy in the netherlands with a vauxhall (2.0 16v) 150pk with a group A exhaust, camshafts and throttle bodies he went to 204hp.

←

And if it really made 204hp (on an engine dyno, i.e. not in the car ;) ) it probably came on cam at 3000rpm and made useable power from 6k to 8k rpm. And the mods you list are only the start of the cost, you need an aftermarket/piggyback ECU and and mapping time.

You might well be able to tune the length of the runners to optimise the powerband with throttle bodies, but with the stock induction, you have a varying inlet length, i.e. no compromises.

You know about ACIS on you engine, presumably?

http://turbomr2.com/MR2/Reference/TVIS/TVIS.htm

[hkspeed]

i heard about the tvis (thanks for the link) but i thought that my car a 1997 st202 didn't have one but i was apperently wrong (i thought only on mr2's).

T vis indeed is a nice systeem but i my opinion the only way you can have a high powered n/a 3s-ge is with a ported head, nice cams and itb's and a stand alone ecu and if you got extra cash you can make it a 2.2

What is your opinion a high powered third gen 3s-ge i mean what sort of modefication should you do.

the guy with the vauxhal, i forgot to mentioned the DTA stand alone ecu.