Intake Manifold discussion. Tech debate.

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Intake Manifold discussion. Tech debate.

Postby ChrisD » Mon Oct 04, 2004 7:28 pm

Alright, the other intake manifold thread was way too long and way off the topic I want to discuss.

We now know that it has been proven that the RMR intake manifold can potentially add 30-50whp to your 3SGTE. The examples that I can think of are:

1. Bill Price's car, who went from 333awhp to 368awhp. His dyno graph comparison is here: http://home.covad.net/~billprice/Cars/dynocompare.jpg . Bill has a standalone ems for engine control.

2. JekylandHyde from the mr2 board: 258whp to 302whp. The only adjustment made was a 1psi fuel pressure increase. His mods include Supra 550cc/min injectors, SAFC, and HKS VPC, which were left alone. The thread where he discusses this is here: http://www.mr2oc.com/showthread.php?s=& ... genumber=1

Now, here are the issues I'd like to talk about.

- At what power level does it become beneficial to do an intake manifold upgrade? Hyde has shown that 258whp will definitely see good results. What about 240, 230, 220, 200, or even a stock ~150-160? Obviously there is some sort of diminishing returns as we go down in power. But where does it start to make sense?

- How well would the STOCK ecu cope with a bigger manifold? If one had an adjustable FPR, would you be able to properly compensate for this manifold using the FPR and a wideband to tune? Since the stock ECU monitors air flow with the AFM, will the addition of the intake manifold cause an increase in injector duty cycle, or would the duty remain constant since boost is staying the same? Obviously a person in my position would likely find problems with injector sizing, but thats a discussion for another topic. It could possibly be counteracted with enough fuel pressure, but that would have to be tested with a wideband and I'm not sure we can comment on that...

- question for BILL: When you installed the intake manifold, did you make any changes to your fuel or timing maps on your EMS?

- Will the addition of the RMR intake manifold change the engines propensity to detonate? Will the intake charge be cooler because the air is more able to flow freely? Will you risk detonation more simply because there is more air flowing into the engine?

That's all I've got for now. I'd like to see what people have to say about this. Please don't go off topic here. I don't care if you think this manifold is a rip off or not. Lets just talk about how an aftermarket manifold will affect the 3SGTE.

Hopefully this could be useful for people in the future, if there is enough interest in the topic.

Chris
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Postby RedCelicaTRD » Mon Oct 04, 2004 7:41 pm

As long as you still have an AFM on your car the ecu will be able to make the correct fueling changes. Boost doesnt matter at all on a stock ecu'd car, only cfm does. This manifold will change how much air you can push into the engine which will change the cfm amount. The ecu will see this with the AFM and add fuel accordingly. The only way you would detonate more with this intake manifold is if you ran out of fuel due to increased flow. If you where already running you stock injectors at 80% duty and then added this manifold you would have problems. If you already a decent intercooler adding this manifold could lower the intake temps due to the fact there is less restriction and the turbo wouldnt have to work as hard which could help put the turbo into a more efficient zone.
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Postby furpo » Mon Oct 04, 2004 7:56 pm

just to add to the questions the idea of quad throtle bodies.

i have been thinking for a while of using the tvis as throtle bodys in a similar way to the gtir nissan pulsar/sunny and the gtr skyline. the reason is my car is always going to be a road car so it will have to get good fuel economy and when the tvis is disconected i have noticed i get about 60km less to a tank of gas. hopefully using going this way will solve the low end fuel emulsifcation problems the gen 2 engine has.

what do you guys and girls think.

obviously the aftermarket intake manifold is only going to be any good when the standard manifold has reached it's limit. it would be interesting to know where this is.

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Postby ChrisD » Mon Oct 04, 2004 8:41 pm

RedCelicaTRD wrote:The ecu will see this with the AFM and add fuel accordingly.


That is true. However, I'm not sure it would do this at the limit of the stock ecu so to speak. Like for me. I'm pushing a good 250 awhp right now and running extremely rich. The stock ECU does one of two things. 1) adds fuel all the way up to 100% duty; or 2) adds fuel up to a maximum allowable duty cycle, some level chosen by the ECU. I don't know which it does. I wish I had a way to monitor my duty cycle and I would know much better. If (2), then you could compensate with an adjustable FPR. If (1), then the ECU will theoretically adjust for you, however become closer and closer to dangerous duty cycle levels. Anyone know what it does?

I have access to an SAFC. Does it monitor duty cycle? I'd be willing to install it and record what happens.

RedCelicaTRD wrote:The only way you would detonate more with this intake manifold is if you ran out of fuel due to increased flow.


I would definitely want to watch on a wide band to see what happens. One would definitely have to have the supporting mods to go this route. Some type of rail upgrade (Im thinking of doing a dual feed setup), a better fuel pump, and an adjustable FPR.

This begs the question; could one install this manifold and turn DOWN the boost, and make comparable hp and torque? This lends itself to much lower intake temps which are always nice.

RedCelicaTRD wrote:If you where already running you stock injectors at 80% duty and then added this manifold you would have problems.


Unless I increased fuel pressure...but there are limits to this as well.

RedCelicaTRD wrote:If you already a decent intercooler adding this manifold could lower the intake temps due to the fact there is less restriction and the turbo wouldnt have to work as hard which could help put the turbo into a more efficient zone.


I have an ST185RC intercooler. I like to think it does a pretty good job. I also have water injection, and I plan to upgrade the IC heat exchanger this winter. Anything to help keep cool. :smokes:

A few people have discovered that one can make 275 whp on the stock ECU before you start to run into problems with injectors. I am looking to make this while keeping my boost levels relatively low. Intake manifold seems like a really good mod to help me get there. Just need to know how to do this safely...
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Postby Zeus » Mon Oct 04, 2004 11:08 pm

Oy lots of questions...

first off ide like to say that while the rmr manifold looks great... Chrisk makes manifolds that will give all the power gains (maybe a couple hp less at peak) but not lose as much low end if any... if your seriously considering this i would suggest talking to him and see what he says...

one thing i would wonder about is maxing out the stock afm.. i dont know if this is possible or what (i dont like afms :P)

but bottom line your going to be getting much more air into the cylinders and this means more power... im not sure if an fpr would be enough as far as tuning is concerned... but i wouldnt be suprised to hear that it is either... as long as your not maxing out the stock injectors then you should be fine. so in this respect yes you could turn down the boost... wether it be to stay inside your injector range or purely for the sake of making similar power at lower boost (has many benefits on things like longevity but also your ic wont heat soak as fast)

the safc doesnt show your duty cycle... they put that on the avcr... now thats marketing huh..

you could make your own or im sure you can get a duty cycle monitor somewhere..

I wouldnt think the stock ecu would run 100% duty when its out of its mapping but that duty cycle monitor would certainly show you that!

as far as detonating is concerned... a properly designed intake manifold will actually help gaurd against detonation in the sense that you dont have the two hot cylinders any longer... other than that its up to tuning

when does an intake manifold make sense?

well i personally think its all about bang for the buck... and it also depends on your set up... if youve run out of bolt ons to do there is little else right? i think intake manifold and cams are right on the same level.. once you get to that level its really one or the other.. im having a hard time deciding which i should do next...

hopefully that answers a couple questions
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Postby Zeus » Mon Oct 04, 2004 11:14 pm

Oh and personally i think the tvis quad throttle body is not a good idea...

the tvis is designed as an off system.. it doesnt have the acuracy needed for a trottle body not at all being an on off switch.. so you would be no throttle or wide open... im sure you could try to rig up a set up that is more acurate using the traditional idea of a throttle body.. but that would be a lot of wasted money i think...

if you want quad throttle bodies do quad throttle bodies...

I personally think there would be minimal benefit to doing that

also another thing you should remember is that the stock manifold blows... the whole reason for this thread... so you would be designing around an allready flawed set up with hardware not meant to do what your asking of it...
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Postby enzytebob » Mon Oct 04, 2004 11:49 pm

I like the Ross Manifold, too.

The question I want to ask those who are familiar with fuel limits and duty cycles is: can one reach a dangerous level (insufficient fuel supply) if the wide-band still reads rich at WOT? In other words, can I keep on adding mods, like a Ross manifold, 264 cams etc and after having done so, if the wideband still shows that the fuel mixture goes rich when i let the hammer down, does that mean I'm still safe? Or can i run rich but max out my injectors?

Can't i let the wideband tell me when i am approaching the danger zone of running lean at WOT when I see it reading 13 to 1 a/f instead of 11.5 to 1?
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Postby BoostedBlueToyotas » Tue Oct 05, 2004 12:08 am

Chris,

We need to talk. How close are you to doing all of this. I am
contemplating the RMR but I am fussing over having to reroute
lines (PS idle up and Pwr brake line = easy, TB coolant lines
= ouch) and losing the TVIS stuff. Initially I will have CT20b
and Aussie DP,MP, HKS Hiper cat back. Running new short block
and rebuilt head with HKS 264 and valve springs. Running stock
injectors, balanced to 460 by RC engineering. Stage II (after
engine is broken in) will be
a 205 WTA (already have the parts except for one pipe and the
hoses) and VPC (already have and it has been programmed for
an alltrac not an MR2) with straight intake. Also going to put an adjustable
FPR on in stage I (probably from Wolfkatz). If this sounds close to
what you are doing I would love to compare notes. I am ready to
degree the cams and put in the car (unless I get the RMR then I
am going to have to wait)
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Postby alltracman78 » Tue Oct 05, 2004 1:07 am

If you'r not running lean you are getting enough fuel. However, it's never good to max out a system, especially the fuel system. Maxing out leads to early failure. For instance, running a injector at 80% or higher duty cycle isn't bad because you will be running lean, it's bad because it's stressing the injector out, and it could fail at any time, which would of course lead to lean conditions, det, ect.

I would definitly NOT use the T-VIS for quad tb. It only works on 4 of the 8 runners, anyways.

Why do you need to keep the coolant lines for the tb? Unless you live in a REALLY cold climate, all it does is help to heat up the intake air.
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Postby furpo » Tue Oct 05, 2004 1:40 am

i plan to have the tvis cnc machined (i have access to one) and use it as throtle bodies with a different manifold. i was just woundering if anyone had tryed it. sounds like it may not be worth it. i have not decided on anything so i don't mind if it i get told it will not work. in fact it is good because i will not waste my time and money on it.

thanks for the feed back
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Postby illGT4 » Tue Oct 05, 2004 2:29 am

Blue_GreyST185 wrote: I am
contemplating the RMR but I am fussing over having to reroute
lines (PS idle up and Pwr brake line = easy, TB coolant lines
= ouch) and losing the TVIS stuff.


The TB coolant lines can be removed. No need to even run those up there.

And when going with an aftermarket inake manifold, whether it be RMR, HUX, JUN or of Chris Kattage design, you'll most likely get rid of the T-VIS anyway.

Any aftermarket intake manifold is going to make more power than the stock intake manifold. T-VIS or not.

The RMR manifold is great for the money you spend. Good max power, but lack of good torque. The Chris Kattage intake manifold doesn't loose as much torque. But is more money. You get what you pay for. The RMR makes great power per price ratio.
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Postby ChrisD » Tue Oct 05, 2004 6:35 am

Zeus wrote:Oy lots of questions...


hehe. gotta pass the time somehow!

Zeus wrote:first off ide like to say that while the rmr manifold looks great... Chrisk makes manifolds that will give all the power gains (maybe a couple hp less at peak) but not lose as much low end if any... if your seriously considering this i would suggest talking to him and see what he says...


I had forgot about his work. Most seem very happy with what he has done. I have searched and I'm having trouble finding pics, prices, etc. on the net. I can't find any dyno sheets either, except reference to them on the old mr2 board which doesn't exist any more. :( Do you have any link I could look at? I will email him and maybe get him to chime in if he doesn't mind. :D

Zeus wrote:one thing i would wonder about is maxing out the stock afm.. i dont know if this is possible or what (i dont like afms :P)


I believe RickyB has stated that the stock AFM will be limited to about 300whp. I agree, it's not my first choice either. Just working with what I have.

Zeus wrote:but bottom line your going to be getting much more air into the cylinders and this means more power... im not sure if an fpr would be enough as far as tuning is concerned... but i wouldnt be suprised to hear that it is either... as long as your not maxing out the stock injectors then you should be fine. so in this respect yes you could turn down the boost... wether it be to stay inside your injector range or purely for the sake of making similar power at lower boost (has many benefits on things like longevity but also your ic wont heat soak as fast)


Also less detonation. Less boost has a lot of positive aspects to it. I'd much rather make 250awhp on 12psi instead of 14! Watching the EGT gauge is interesting when playing with boost. You have to be pretty careful sometimes.

Zeus wrote:the safc doesnt show your duty cycle... they put that on the avcr... now thats marketing huh...

you could make your own or im sure you can get a duty cycle monitor somewhere..


Damn, that figures. lol. I'm sure a monitor could be picked up for cheap enough...not sure I want to shell out the money for one though. Donations anyone for a good cause? 8)

Zeus wrote:I wouldnt think the stock ecu would run 100% duty when its out of its mapping but that duty cycle monitor would certainly show you that!


My thoughts as well. Be it 95%, 90%, or whatever, I cant see the stock ecu actually going to 100% and staying there. Regardless, this means that at a certain point, if you increase airflow, fuel supply will stay the same. That means you will be getting leaner and the only way to add fuel is with an FPR...while you are on the stock ECU of course.

Zeus wrote:as far as detonating is concerned... a properly designed intake manifold will actually help gaurd against detonation in the sense that you dont have the two hot cylinders any longer... other than that its up to tuning


Good point. This along with a better fuel supply (dual feed, wolfkatz, etc), would go a long ways to ensuring a safer engine when tuning for a target A/F.

Zeus wrote:when does an intake manifold make sense?

well i personally think its all about bang for the buck... and it also depends on your set up... if youve run out of bolt ons to do there is little else right? i think intake manifold and cams are right on the same level.. once you get to that level its really one or the other.. im having a hard time deciding which i should do next...

hopefully that answers a couple questions


Yeah I am definitely running out of bolt ons...I've even got a set of Supra TT injectors waiting to go in if I could find a way to properly control them. Still working on that one... It's basically at the point where it's cams, EMS, or intake manifold. Even though EMS is "safer", it introduces a whole new realm of danger to the engine. That means I have to find a tuner which I feel comfortable tuning my engine...not sure I can do that short of flying someone in. Thats one of my reasons for leaning away from EMS...I'd rather do mods that I can understand and control myself.
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Postby ChrisD » Tue Oct 05, 2004 6:37 am

enzytebob wrote:I like the Ross Manifold, too.

The question I want to ask those who are familiar with fuel limits and duty cycles is: can one reach a dangerous level (insufficient fuel supply) if the wide-band still reads rich at WOT? In other words, can I keep on adding mods, like a Ross manifold, 264 cams etc and after having done so, if the wideband still shows that the fuel mixture goes rich when i let the hammer down, does that mean I'm still safe? Or can i run rich but max out my injectors?

Can't i let the wideband tell me when i am approaching the danger zone of running lean at WOT when I see it reading 13 to 1 a/f instead of 11.5 to 1?


Yes. You can be rich while running a duty cycle of 100%, which is very dangerous. The injectors could freeze open or shut, and no longer operate. The rate of injector failure increases a lot when you run very high duty cycles.
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Postby ChrisD » Tue Oct 05, 2004 6:43 am

Blue_GreyST185 wrote:Chris,

We need to talk. How close are you to doing all of this. I am
contemplating the RMR but I am fussing over having to reroute
lines (PS idle up and Pwr brake line = easy, TB coolant lines
= ouch) and losing the TVIS stuff. Initially I will have CT20b
and Aussie DP,MP, HKS Hiper cat back. Running new short block
and rebuilt head with HKS 264 and valve springs. Running stock
injectors, balanced to 460 by RC engineering. Stage II (after
engine is broken in) will be
a 205 WTA (already have the parts except for one pipe and the
hoses) and VPC (already have and it has been programmed for
an alltrac not an MR2) with straight intake. Also going to put an adjustable
FPR on in stage I (probably from Wolfkatz). If this sounds close to
what you are doing I would love to compare notes. I am ready to
degree the cams and put in the car (unless I get the RMR then I
am going to have to wait)


We seem fairly similar, minus the cams and VPC. I've got the ct20b, water injection, 185RC WTA IC, intake/exhaust, JDM engine/ecu, tte metal hg, adjustable FPR, fuel pump, clutch and flywheel, and a bunch of gauges.

I think I might look into the merits of a VPC as well, but I'm not all that familiar with how it works.

I wouldn't worry about loosing the TB coolant lines. Mine are already removed from the system (just running them in a loop to bypass the TB) which took 5 minutes. I had to do this since the valve was cracked and leaked pretty good. lol

If you want to chat about our set ups, shoot me an email at chris_dittrick@yahoo.ca . :)
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Postby ChrisD » Tue Oct 05, 2004 6:45 am

illGT4 wrote:And when going with an aftermarket inake manifold, whether it be RMR, HUX, JUN or of Chris Kattage design, you'll most likely get rid of the T-VIS anyway.

Any aftermarket intake manifold is going to make more power than the stock intake manifold. T-VIS or not.

The RMR manifold is great for the money you spend. Good max power, but lack of good torque. The Chris Kattage intake manifold doesn't loose as much torque. But is more money. You get what you pay for. The RMR makes great power per price ratio.


I am not familiar with the prices of the other manifolds. Do you happen to know how much each would run? Trying to compare the options is difficult when most of the companies don't have a web page to refer to. :)
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