Budget Intake Manifold/TB Options

[deflator]

So I'm broke, the head is off the car, and I need to do something about my stock intake manifold before I put her back together. The crappy stock 2g intake mani and TB is all that I haven't addressed yet.

What I want is an evo 3/RVR mani. and TB, but can't find one for under $200.

I have a lot of free time and some porting media on hand, so I could either try to work the 2g manifold into something (thought I can't find any helpful info on this), or get a 1g manifold and port the head to match. If anyone knows how much material needs to be removed for a 1g manifold let me know. I can't figure out if it is worth it or not.

Either way I want to replace the throttle body, should I go with a 1g N/T or 1g Turbo throttle body?

Thanks for any input, and if anyone has these parts to sell PM me about them

 

[HIGHPSI4]

The 1G manifold and TB is a cheap way to go. The NT and turbo TB have the same passage size. As for porting, use a new intake manifold gasket to compare to.

 

[deflator]

The 1G manifold and TB is a cheap way to go. The NT and turbo TB have the same passage size. As for porting, use a new intake manifold gasket to compare to.

I don't have a 1g gasket lying around, but from comparison to pics of 1g heads, porting the head for the 1g mani looks like a hell of a job, probably would have to buy more carbide porting media just to get it done and I am really looking to avoid expenses here. Anyone who has actually done this, how many hours did you have into the porting? I'm pretty good at it, but only have theoretical knowledge of porting for flow on cylinder heads. The ports look almost twice the size on a 1g head so I'm sure the bowl area is way different as well, porting the runners isn't all there is to it I'm sure. If I'm going to have to turn it into a 1g head I might as well try to trade it for an actual 1g head

What I really would like to do is port the 2g mani but I can't find any good info on here about it

 

[pboglio]

A 1g throttlebody is designed for boost pressure without the need for changing the shaft seals.

I gasket match ported the EVOIII intake manifold to the stock 2g head. All you need is a die grinder, carbide burr, a tree shaped stone wheel, an 80 grit sandpaper flapper wheel, 2g intake manifold gasket, scribe, dykem red or blue. Its about an hour job if you know what your doing. Rough cut with the carbide burr and leave enough material so you can fine cut with the stone wheel, then final polish with the 80 grit etc. flapper wheel.

 

[Boostjunki84]

While the 1g manifold and TB are superior to the stock 2g parts, a 1g manifold on a 2g head will hurt performance more then it will help. The ports do not match up well at all, and with how much you would have to port the 2g head, it could just further decrease performance. I was thinking of doing the same thing at one point, but after some research, I realized it would be more benificial for both performance and my budget to either switch to a 1g head with the 1g IM or get good quality cast or SMIM.

As for the TB, like HIGHPSI4 posted above, the bore is the same. You may also want to check here:DSM THrottle Bodys

 

[deflator]

I gasket match ported the EVOIII intake manifold to the stock 2g head.

Ideally, this is what I would do. I have all the tools, but my budget is pathetic due to illness right now, so even the evo3 is out of my reach. Unless anyone knows of one for a great price

While the 1g manifold and TB are superior to the stock 2g parts, a 1g manifold on a 2g head will hurt performance more then it will help

Thanks for confirming that, it sounded more trouble than it was worth.

But if I got aggressive with the 2g manifold, really got into the runners and ported the head to match a larger runner size...? Hasn't anyone really tried this before? The insides of the 2g mani. runners look like crap, flashing and odd angles all over the place

 

[pboglio]

2g intake manifold runners are MUCH smaller than the stock 2g head ports, thats why you gasket match. Anything more than a gasket match and you have little surface left for sealing on a 2g intake manifold.

 

[Boostjunki84]

Have you considered getting your stock 2g IM Extrude Honed?

FFWD Connection - Race Injuns That Will Freeze Your Brain

 

[pboglio]

For $440 to gain near nothing, thats not a budget intake manifold.

 

[deflator]

2g intake manifold runners are MUCH smaller than the stock 2g head ports, thats why you gasket match. Anything more than a gasket match and you have little surface left for sealing on a 2g intake manifold.

I see, yeah there wouldn't be much left after opening it up even a modest amount. Can't be much gain from the 1-2mm around for gasket matching

 

[Boosted98gsx]

2g intake manifold runners are MUCH smaller than the stock 2g head ports, thats why you gasket match. Anything more than a gasket match and you have little surface left for sealing on a 2g intake manifold.

Don't ruin a perfectly good 2g head by gasket matching to a 1g runner. If you want 1g, get a 1g head. There are those that prefer a stock 2g intake port because of the higher velocity into the combustion chamber, sell it to them.

 

[99redgst]

I just picked up an evo III intake for 100 shipped off of ebay last week. Might take a little while but you can find them for a reasonable price.

 

[the_mork]

The RVR/E3 manifolds are worth waiting for and available at a decent price.

Learn to recognize them by sight and you'll find them when people pull them off of their "JDM Eclipse" engines which are usually RVR motors. I picked one up off of ebay for $150 but two weeks later I saw a guy selling two on dsmtrader.com for $120 each.

Also a 1g turbo throttle body may already have turbo seals but you should really rebuild it anyways so base your decision on whether or not you want/need a throttle body elbow. If you don't need one then get a n/t tb.

 

[deflator]

Also a 1g turbo throttle body may already have turbo seals but you should really rebuild it anyways so base your decision on whether or not you want/need a throttle body elbow. If you don't need one then get a n/t tb.

Yeah I just dug deep and bought the evo3/RVR manifold. Not sure on the TB though, I guess I'd need a long 45* silicon coupling if I wanted to do away with the TB elbow and that sounds expensive.

 

[Boostjunki84]

For $440 to gain near nothing, thats not a budget intake manifold.

True; it's just another option. I mentioned it because the OP seems to want to try and use the 2g IM he has now. Also, he's running a Big T28, and would loose power in lower RPMs with a SMIM like a JM Fab or Magnus. By using the Extrude Hone process, he would retain most of his power in the lower RPMs and gain power in the higher RPMs as well.

I agree, that it is not quite budget, but it's less expensive than most SMIMs on the market.

To the OP, do you plan on continuing to use the T28, or do you have plans to upgrade in the near future? If you are planning on going with something bigger than a 16g, I would go ahead and get a SMIM; if not, I would look into the Extrude Hone process or switch to a 1g head/IM.

EDIT: I see you already got an evo3/rvr.

 

[pboglio]

There is no low end on a 2.0 liter, even with a T28. Anything you can do to open up the topend just increases the powerband. SMIM are great if you have the money, like to realign your upper I.C. pipe, ditch the stock battery, like the possibility of cracking, etc. Otherwise the EVOIII intake manifold is a great 2nd alternative with much higher OEM reliability.

 

[deflator]

To the OP, do you plan on continuing to use the T28, or do you have plans to upgrade in the near future? If you are planning on going with something bigger than a 16g, I would go ahead and get a SMIM; if not, I would look into the Extrude Hone process or switch to a 1g head/IM.

I plan to switch to a Holset Big H1C w/BEP housing soon. And the T28 I have is the Killer, which is actually a Big 16G sized turbo.

I don't think an SMIM will ever be in the budget for this car, you just have to stop somewhere right?

 

[Boostjunki84]

There is no low end on a 2.0 liter, even with a T28. Anything you can do to open up the topend just increases the powerband. SMIM are great if you have the money, like to realign your upper I.C. pipe, ditch the stock battery, like the possibility of cracking, etc. Otherwise the EVOIII intake manifold is a great 2nd alternative with much higher OEM reliability.

There is a low end; the lower end of the powerband. An aftermarket cast or SMIM will move the powerband up, increasing power in the higher RPMs. However, you will actually loose power in the lower RPMs because that additional power is not realized until later in the RPM range. Larger turbos can have a similar effect.

 

[All_Boost16G]

I had the same budget idea. So I went out a bought a 63mm 1g throttle body, and ported the intake manifold. Cheap and effective I think.

 

[z24frank]

where are you guys seeing these on e-bay i havent seen one forever on there?

 

[pboglio]

There is a low end; the lower end of the powerband. An aftermarket cast or SMIM will move the powerband up, increasing power in the higher RPMs. However, you will actually loose power in the lower RPMs because that additional power is not realized until later in the RPM range. Larger turbos can have a similar effect.

Most people that have installed street versions of a SMIM don't notice this loss of lowend. I was expecting the same thing with my EVOIII intake manifold and hardly noticed any loss if at all and the tuning peak for that manifold is at least 500 rpm higher or more than stock. The topend however is where I've seen gains and the powerband increased as well.

Lowend power is subjective. Try this, put the car in 2nd gear from a stop and let out the clutch and try and keep up with traffic. Next, try and hit WOT at 2,000 rpms in 3rd gear.
These things I can do easily with my 2.5 Liter turbo motor without complaint. There is that famous "topgear" Mitsubishi EVO vs. an economy car test that ilustrates this. They slapped both cars into 5th gear at low rpms and a tin can 4 banger econobox pulled away from the EVO for nearly a mile before the EVO caught up.

 

[Boostjunki84]

Most people that have installed street versions of a SMIM don't notice this loss of lowend. I was expecting the same thing with my EVOIII intake manifold and hardly noticed any loss if at all and the tuning peak for that manifold is at least 500 rpm higher or more than stock. The topend however is where I've seen gains and the powerband increased as well.

True. But while you may not notice the loss of lowend, the fact remains that the loss is still there. Each application will be different, but any dyno will show the loss of power in the lower RPMs.

http://www.magnusmotorsports.com/images/evo_oem_vs_cast.jpg
http://www.magnusmotorsports.com/images/evo3037_oem_vs_cast.jpg

I agree that the EVOIII IM is a good choice for a budget street car and the gains are probably comprable to that of the Extrude Hone process I mentioned before. The EVOIII IM would also net lower loses in the lowend than an aftermarket cast or SMIM. It also has that benifit of being cheaper, albiet harder to find.

 

[deflator]

Yikes, that seconds graph shows the magnus down on the stocker by as much as 65ft/lb @ 4500rpm! All for an extra 50hp up top and 500 or so extra rpm before it drops off? That just doesn't sound like its worth $600 something for a street car

 

[Boostjunki84]

Yikes, that seconds graph shows the magnus down on the stocker by as much as 65ft/lb @ 4500rpm! All for an extra 50hp up top and 500 or so extra rpm before it drops off? That just doesn't sound like its worth $600 something for a street car

This is what I was saying about loosing power in the lower RPMs. Looking at the dyno sheet the new IM looses power from about 3k until just before 5k. However, from 5k up until just before 8k it makes more power. This is what pboglio was saying about gaining in the higher RPMs.

If you look at the dyno sheet again there is one point in the higher RPMs where the IM makes close to 75hp over the stock manifold. Remember, this particular car in the second graph was using a GT30. So, moving the powerband up would be desirable because the turbo doesen't spool up until about 800rpms later vs. the stock turbo on the first dyno sheet.

 

[deflator]

Remember, this particular car in the second graph was using a GT30. So, moving the powerband up would be desirable because the turbo doesen't spool up until about 800rpms later vs. the stock turbo on the first dyno sheet.

Yeah but if I can get full boost by 3500rpm on a H1C there's no need to move the powerband up, revving to 7500rpm would be enough for a good street car making around 400whp I should think. Ugh I'm probably going to run out of fuel pump before that though