[Mk2] [Turbo] Which Cams to get?

[Andy F]

Just get a rev3 head cams and manifolds and bolt it to your rev2 block
using a stock rev3 gasket, no isuses what so ever.
i have been running 2 bar boost with a gt3076 for ages, no idea what power its running but 11.5 @ 124mph consistant is pretty good.
My car drives like a stock mr2 but mega fast and thats what we all want
when we start modding em!!!
good mapping helps too

[salamanzer]

Before throwing money at the car i would assume you have checked the usual;

Cars not running rich
Air filter is clean
de-cat if possible
uprated exhaust manifold

Also if you want a use-able power band you want an inlet cam with a huge lift, but small duration and an exhaust cam with good lift (10.5ish) and a small duration else you will be a lumpy idle, and spool will suffer.

The larger the duration, the more you will push the power up the rev range.

As for the manifold, a custom job would be cool, but they must be designed based on the following,

intended peak power rev range
single/dual rail
TB size

I would go custom plenum, runners and trumpets. I show a AMS below (which is for an evo for illustration only)



^^^^
Something like that would be ideal, and something im looking towards getting made for myself should the current custom plenum i have fitted to the car becomes an issue at the power levels im looking to run.

Jason

[^Trickster^]

Jason: You have mentioned uprated exhaust manifold, do you have any evidence that a aftermarket manifold yeilds more power than the stock one?

I say this because alot of people tend to fit them and see no noticable diffference over cars running similar setups with stock manifold and adaptor plates, I have always gone this route.

The stock manifold is short and its cast iron which means it retains the heat much better than a longer stainless one, and its heat that spools a turbo not exhaust flow.

I am also not saying that aftermarket manifolds are useless, but I am interested in the other side of the coin, I have just never noticed a restriction, the only time I would change it is when your moving to a turbo which simply wont physically adapt to the manifold and you need to go top mount or similar.

Graeme

[salamanzer]

Jason: You have mentioned uprated exhaust manifold, do you have any evidence that a aftermarket manifold yeilds more power than the stock one?

I say this because alot of people tend to fit them and see no noticable diffference over cars running similar setups with stock manifold and adaptor plates, I have always gone this route.

The stock manifold is short and its cast iron which means it retains the heat much better than a longer stainless one, and its heat that spools a turbo not exhaust flow.

I am also not saying that aftermarket manifolds are useless, but I am interested in the other side of the coin, I have just never noticed a restriction, the only time I would change it is when your moving to a turbo which simply wont physically adapt to the manifold and you need to go top mount or similar.

Graeme

Graeme,

It really depends on what you want from your car, mine (hopefully/fingers crossed if the block doesn't crack) will be running 800+

With any OEM manifold its a cost/performance/space ratio that toyota would have been working on. Looking around IMOC, the stock manifold seems fine to the 400 mark....

Top mounts allow you to run the turbo in a more accessible position should you want to move to a boot mount intercooler arrangement. But you cant really beat a well designed and proportioned system that has been designed for your goals in mind.

Same with the inlet manifold, an under-length runner system into the head can net you up to a huge 1/3 loss in power!

Cast iron will retain heat, but i wonder if it retains heat better than my ceramic coated and wrapped tubular manifold, ummmm....

Again it comes down to what you want from the car, ultimately the engine is an air pump, and the head is 99% of what gives the car its power as that is the only part allowing gasses in and out.

If your happy to keep with the standard exhaust/inlet manifold i would get the head worked on.... but don't go too wild on duration!! Piper do some high lift cams >10.5mm which you should use for the inlet cam, less lift and duration on the exhaust side will allow you to retain the spool, but at the cost being top end power.

Jason

[oBladeo]

I've just had fitted
Hks 264 in and out
Hks pullies
Duel sprung valve springs
and ferral valves

Not sure on the power yet or flow as the engine is still in the bedding in stange. I went for this setup as i still want to use the car for everyday driving and heard alsorts about the 272

I love the inlet looks amazing and i've seen quite allot of custom inlets knocking about. I know hux racing do one or two as well



http://huxracingusa.com/huxweb_006.htm

This is on the shopping list

[greeny]

On a side note, i got my cams from www.nengun.com

The cheapest i could find at the time!

[salamanzer]

That looks like a very nice intake, here is mine (but not polished)


But the only downside is not being able to have a second rail fitted, which i might need in the near future....

So i might get my mate to build a new custom one

Jason

[Leakie Tbar]

That looks like a very nice intake, here is mine (but not polished)


But the only downside is not being able to have a second rail fitted, which i might need in the near future....

So i might get my mate to build a new custom one

Jason

Jason who said you can't have a secondary set of injectors

There should be no problem adding a secondary set on that existing manifold..

[salamanzer]

The manifold has been looked at by quite a few people, and a second rail could be fitted BUT it wouldn't be ideal, so the idea was abandoned.

I think if i go down the route of a second rail i might get another manifold made....

The injectors fitted should net me the power i want so a 2nd rail would be worse case scenario, currently they are only running something like 45% duty....

[^Trickster^]

salamanzer: I just made 470 flywheel hp on the stock exhuast manifold at 1.4 bar, I also have a completely stock head except for 272/264 int/exh cams normal lift. Ryan is maping it to 2.0bar next week.

I do agree that a stainless manifold ceramicoated and wrapped would hold the heat well, but i think coated and wraped cast iron would hold better, I also think its much stronger and obviously much less prone to cracking as it doesnt stress like a longer length manifold.

Alot of people seem to make un neccesary ram horn style exhaust manifolds, dont you think this is a little much? Shorter runner to the turbo will yeild better performance in my opinon, whats your take on that?

I do think for 800hp goals a aftermarket is neccesary but more for the fact of positioning of the turbo rather than restrictiveness of the stock manifold, then again the runners are probably a little small for the larger gt40/42 turbos and a aftermarket would be ideal with a worked head at this point.

I also run a rear mounted rmr intake manifold, which is where i think money is better spent rather than on headwork if you going to be under the 600 flywheel hp mark.

I dont like 2 fuel rails either, I know people like them for more controllablity and better idle, but alot of modern large injectors and ems combinations can idle perfectly fine, im running a lower than stock base pressure and getting max of about 70% peak duty cycle on 1000cc

What spec is your setup? Should be interesting

Graeme

[oBladeo]

^Trickster^ you should see salamanzer mr2

http://www.imoc.co.uk/forums/viewtopic. ... sc&start=0

He's changed allot and it's running allot more power now :O

[Leakie Tbar]

Gen 3 head dude RMR is a no go

[Marf]

Just get a rev3 head cams and manifolds and bolt it to your rev2 block
using a stock rev3 gasket, no isuses what so ever.
i have been running 2 bar boost with a gt3076 for ages, no idea what power its running but 11.5 @ 124mph consistant is pretty good.
My car drives like a stock mr2 but mega fast and thats what we all want
when we start modding em!!!
good mapping helps too

What spec is the rest of the engine?

[^Trickster^]

Looks like a T88 or something. graph is probably like this


_____________/ lol

Kev: RMR will make a manifold to go on the rev 3 head, but only to order. Stop spending time on here and get your beast built!

Graeme

[Leakie Tbar]

Looks like a T88 or something. graph is probably like this


_____________/ lol

Kev: RMR will make a manifold to go on the rev 3 head, but only to order. Stop spending time on here and get your beast built!

Graeme

I am at graft you loon,, got to pay for the new kitchen first

[^Trickster^]

Dont fill me with that lol, you have enough parts to build 3 mr2s! lol

[salamanzer]

salamanzer: I just made 470 flywheel hp on the stock exhuast manifold at 1.4 bar, I also have a completely stock head except for 272/264 int/exh cams normal lift. Ryan is maping it to 2.0bar next week.

I do agree that a stainless manifold ceramicoated and wrapped would hold the heat well, but i think coated and wraped cast iron would hold better, I also think its much stronger and obviously much less prone to cracking as it doesnt stress like a longer length manifold.

Alot of people seem to make un neccesary ram horn style exhaust manifolds, dont you think this is a little much? Shorter runner to the turbo will yeild better performance in my opinon, whats your take on that?

I do think for 800hp goals a aftermarket is neccesary but more for the fact of positioning of the turbo rather than restrictiveness of the stock manifold, then again the runners are probably a little small for the larger gt40/42 turbos and a aftermarket would be ideal with a worked head at this point.

I also run a rear mounted rmr intake manifold, which is where i think money is better spent rather than on headwork if you going to be under the 600 flywheel hp mark.

I dont like 2 fuel rails either, I know people like them for more controllablity and better idle, but alot of modern large injectors and ems combinations can idle perfectly fine, im running a lower than stock base pressure and getting max of about 70% peak duty cycle on 1000cc

What spec is your setup? Should be interesting

Graeme

Sorry i should have put 800rwhp+

That aside, head work is important, you can push all the boost you want, if its not flowing in and out the head in the most efficient way possible you really arnt getting the best from the engine. The head really does matter that much! F1 cars have mental amounts of head work for that very reason.

I will be interesting to see how the engine responds to 2Bar on a standard manifold, no head work and exhaust manifold. I will imagine that the inlet temps will rise very quickly due to the back pressure from the manifold, and pressure at the valves will be very high and heated air from the turbo gets backed up in the inlet manifold.

At some point you will find throwing more boost at the engine will net you very little in gains, and/or you will get high levels of knock as the inlet temps are too high.

I'm running a GT42RS turbo (rated 1000whp+), so from my point of view getting air in and out the engine is very important to me!

As for twin rails, im running 2200cc injectors so i know what poor idle is LOL, plus as RPM's rise you need to move the injectors further away from the valves to get the fuel/air to mix correctly, so twin rails are very much a good idea!

Horns, velocity stacks etc are their to assist in pressure differentials between pressure at the valves and the plenum which in turn increases air flow through the runners, and stops the air flow from having too much disruption.

Jason

[^Trickster^]

You must not be reading all of the information im giving you.

I have a rear mounted RMR intake manifold, I think you under estimate the amount of air the head can flow in stock form, do you have pictures of how you ported your head?

Most people ruin the flow of the head with inaccurate and inexperienced headwork, I never said headwork was unimportant, I said it was not neccesary for power levels under 600hp, proved many times on many setups.

What are the specs of your engine, 800rwhp is alot to put through the motor reguardless of how much headwork etc you have, even the 2.2 blocks are not strong enough to handle consistant amounts of hard driving at that horsepower, block girdles, sleeving them, filling them with concrete and other stuff to stop cylinder cracking and distortion just doesnt cut the mustard when the engine is that highly strung.

I dont understand how alot of people always use the airpump terminology and then stick to a 2 litre platform with a massive turbo, if getting air "through" the engine is so important then heres some more terminology - theres no replacement for displacement.


Graeme

[^Trickster^]

im running 272s aparently....(so recon ats racing)
no idle problems, sounds LOVELY to..
idle is at 1400 tho, lol.
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How does it idle at stock speed, like 950rpm or whatever? 1400rpm isnt idling really is it lol

My car idles ok, but it idles really smooth at 2000rpm lol

Graeme

[jimGTS]

well i didnt asume folks ment stock idle at 750....
i thought those running cams/large injecotrs have higher than stock idle positions anyway (like mine).
and was just saying where mine is set, it idles fine.

im guessing at lower idle, especially cold, maybe not be so smooth.
havent tried tho as thats where its been mapped and set to.

its not that far off of cold idle really, which is like 1200 on a stock car.