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Old 02-26-2008, 09:02 PM   #1
iRick.
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Default things done before a tune

alright. short and to the point

i don't want to spend $500 on a tune and then decide there was something else i could've done to the engine..so thats what i'm here to ask

within the next few months i am installing

borla headers, custom hfc, espelir catback exhaust

rallitek short ram intake

lightweight pulley

after this i planned to do a tune

but is there anything else not too expensive that you recommend doing first?

i thought about port and polish but unsure about it

thanks for the answers
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Old 02-26-2008, 09:09 PM   #2
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I am getting a tune in a couple of weeks too so people help us out. I recommend new oil change, oil filter, good working spark plugs, check exhaust for leaks. Anything more guys?
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Old 02-26-2008, 09:10 PM   #3
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before you do the intake, chk Williaty's intake setup with the stock snorkus/airbox as it is benifical to keep those in the system with our motors/MAF sensors. Ill get you a link in a min.
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Old 02-26-2008, 09:12 PM   #4
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Quote:
Originally Posted by Forester_007 View Post
I am getting a tune in a couple of weeks too so people help us out. I recommend new oil change, oil filter, good working spark plugs, check exhaust for leaks. Anything more guys?
i will be getting an oil change next week

and the car only has 7000 miles on it

so i shall check the exhaust but not too worried bout the plugs

i dunno..i guess i'll have everything checked out just to be safe
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Old 02-26-2008, 09:18 PM   #5
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well n/m on the link, but Williaty has done lots of testing/logging/tuning with various MAF based inatke setups and the MAF subaru motors dont like the snorkus delete in the low revs (under 2000 or so) due to a MAF sensor error caused by resonation of the intake air charge at those engine speeds when the snorkus is NOT present so he has a setup using a SRI intake tube and connecting it to the stock airbox and snorkus. He said he will have a good writeup on the results with data and whatnot but im not sure when those will be available. In the mean time do everything else as the stock intake is probably the least restrictive in term of HP on the list of stuff you want to replace. thats my opinion anyway. let us know what kind of gains you get with your tune and maybe some details of the tune if you dont mind sharing. good luck.
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Old 02-26-2008, 09:23 PM   #6
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holy ....wow

i tried going through williaty's threads posted and the amount of information and questions is just too much.

i'm no where near knowledgeable when it comes to ECU/sensors/MAF etc

so if i have this SRI

i can install it with the stock airbox and snorkus?

do i replace the filter in the airbox with K & N or something?

thanks
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Old 02-26-2008, 09:28 PM   #7
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you can install the SRI you buy to fit up with the stock airbox (and snorkus) but I think you will also need to buy a piece of flexible hose (silicone) and a couple hose clamps and a MAF sensor adapter of some sort if you cant mount it in ytour new SRI after the modification. Probably should ask Williaty this question as he may have exact parts you will need and sizes, lengths, etc. I think the filter element is a preference thing.. the K/N will be cheaper in the long run, for sure.
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Old 02-26-2008, 09:48 PM   #8
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i guess i don't get it though lol

i've seen many other people just run straight up SRI

whats so bad about that??

does it all have to do with MAF?
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Old 02-26-2008, 10:36 PM   #9
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Quote:
Originally Posted by jibtastic View Post
i guess i don't get it though lol

i've seen many other people just run straight up SRI

whats so bad about that??

does it all have to do with MAF?
Posted this elsewhere, don't feel stupid, it's not exactly a straightforward issue.

The stock intake attempts to satisfy two very opposing tasks. Flow as easily as possible AND minimize MAF error as a result of reverberations at low RPM caused by IM (air isn't flowing constant in one direction). It represents a compromise between the two and needs to be represented that way. The stock intake should be left alone if one does not understand the implications of installing an aftermarket intake. However, with proper tuning (scaling / fueling etc), an aftermarket intake WILL show positive gains above 3000rpms. This has been proven and beaten to death. The MAF error that standard CAI/SRI's produce occurs until around 1600rpm as Willi indicated by the graph. For some, including myself, that do most (okay ALL minus starting the car, and two stoplights) of our driving above this range (mostly highway driving) the pros outweigh the cons.
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Old 02-26-2008, 11:56 PM   #10
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What the big thing about using an SRI straight forward vs. using the "hybrid" SRI tubing connected to the stock airbox and snorkus design that williaty had developed is that the latter will preserve the gain in the lows revs (below 2000-2500rpm or so) in terms of power. using the SRI without also connecting it to the stock airbox and snorkus (like its intended) will almost certainly result in a reduced airflow into the engine due to air moving in both directions (vibrating) in the SRI intake tube. that vibration causes the MAF sensor to read more air going into the engine than there actually is, resulting in a rich condition that is actually less powerful than the stock setup. The snorkus is a specifically designed chamber that helps eliminate this "vibration" so that the air moves forward through the intake and does not "vibrate", so the MAF readings are correct and the resulting AFR's (Air/Fuel Ratios) are also correct. This makes the most power while also being most efficient.

I have a SRI (weapon R) and as a bolt on without tune it seemed to yield some gains in the higher revs, (4000+) but nothing dramatic. BUT, I have the SRI without the stock airbox/snorkus attached and i have a dead spot below 2000 rpm and its worse than it was with the stock intake. I have recently rescaled my MAF sensor somewhat to be calibrated to the larger diameter piping that the SRi has. Since the rescaling of the MAF sensor (via the ECU MAF calibration table) i have noticed that i use less throttle during regular driving around town to achieve the same acceleration. this has been logged with throttle position sensor data along with other parameters so i know its not just me. this is just CL (closed loop) driving. which is driving without exceeding the parameters to shift the ECU into OL (open loop) mode. Rescaling of OL MAF values requires a wide band O2 sensor to get reliable, safe and predictable changes for the better since the ECU does not monitor O2 sensors to adjust the AFR when in OL conditions.

OL is aggressive driving (WOT, fast acceleration, rpm's above 4000) to put it simply. CL driving is normal non aggressive driving with steady throttle control and lower engne speeds, etc..


This is all from reading, logging, reading, common sense and reading. oh yeah, reading too. so if i am inaccurate or explained something incorrectly or poorly, someone please make the appropriate corrections.
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Old 02-27-2008, 12:28 AM   #11
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LTRacer is absolutely right that it's a compromise. For me, it makes sense to use an intake type (hybrid) that doesn't cause a problem that you can't tune out but DOES come so close in performance to a full CAI/SRI that you'll never be able to tell the difference.

Building a race car? CAI/SRI FTW.
Building a daily driver that you want to have a little more punch in? Hybrid FTW.

Keep in mind, this ONLY applies to MAF-based NA H4s.
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Old 02-27-2008, 01:27 AM   #12
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OMG though

reading this is worse than trying to understand my AP calc class lol

none of it makes sense haha.


i'm beginning to understand though...and FYI

i ALWAYS drive "OL"

about 80% of my driving is hard lol

so if anyone can help me with this

plus i'm going to a very recommended source for a tune(harmon motors)..what should i tell them to do?
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Old 02-27-2008, 03:20 AM   #13
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Quote:
Originally Posted by jibtastic View Post
OMG though

reading this is worse than trying to understand my AP calc class lol

none of it makes sense haha.


i'm beginning to understand though...and FYI

i ALWAYS drive "OL"

about 80% of my driving is hard lol

so if anyone can help me with this

plus i'm going to a very recommended source for a tune(harmon motors)..what should i tell them to do?

Slip them a post it note that says +200HP and attach $20k.
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Old 02-27-2008, 11:12 AM   #14
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Quote:
Originally Posted by Subyroo2.5 View Post
Slip them a post it note that says +200HP and attach $20k.
+1, they can do this by putting a red R sticker on your car, but they have to overnight it from JDM or the horsepower fall out in shipment so it's really expensive.
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Old 02-27-2008, 11:50 AM   #15
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Quote:
Originally Posted by williaty View Post
LTRacer is absolutely right that it's a compromise. For me, it makes sense to use an intake type (hybrid) that doesn't cause a problem that you can't tune out but DOES come so close in performance to a full CAI/SRI that you'll never be able to tell the difference.

Building a race car? CAI/SRI FTW.
Building a daily driver that you want to have a little more punch in? Hybrid FTW.

Keep in mind, this ONLY applies to MAF-based NA H4s.
Aren't 06/07s MAP based?

If so, Ty's and LT's comments do not apply Jib
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Old 02-27-2008, 12:53 PM   #16
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No, 06+ have MAF+MAP, however, the MAF seems to be the dominant one. I'm not actually sure how the ECU uses the MAP data. Perhaps in the event of a MAF failure?
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Old 02-27-2008, 01:25 PM   #17
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OP: Get cammed before the tune. delta regrinds. Otherwise you're tuning for not very much.

Kevin
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Old 02-27-2008, 02:14 PM   #18
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Quote:
Originally Posted by subikid View Post
OP: Get cammed before the tune. delta regrinds. Otherwise you're tuning for not very much.

Kevin

well..thats something i've thought of...but you gotta understand i've got school

i can't take apart my engine, send in my cams, and wait for them to return

i'd rather not.
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Old 02-27-2008, 03:57 PM   #19
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Then you're going to spend $500 on a tune that isn't going to be that much better than what you have with just the parts alone.

People have got to understand headers, pulleys, cai, exhaust, etc. on an N/A subaru are just BOLT ONS. You don't NEED a tune to see gains, and even with a tune, you won't be seeing that much difference because you are not altering the breathing and fueling characteristics of the engine to such a great degree.

Some will argue here that "oh you'll see gains with a tune!" Of course you will. But it's money better spent elsewhere until you've gotten some REAL modifications that will require a dyno tune.

Take that money you're planning on a dyno tune, buy a 2nd set of used cams, send those off, and install them, and sell the stock cams.

You'll get more bang for your buck that way.
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Old 02-27-2008, 05:17 PM   #20
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Originally Posted by rougeben83 View Post
Then you're going to spend $500 on a tune that isn't going to be that much better than what you have with just the parts alone.

People have got to understand headers, pulleys, cai, exhaust, etc. on an N/A subaru are just BOLT ONS. You don't NEED a tune to see gains, and even with a tune, you won't be seeing that much difference because you are not altering the breathing and fueling characteristics of the engine to such a great degree.

Some will argue here that "oh you'll see gains with a tune!" Of course you will. But it's money better spent elsewhere until you've gotten some REAL modifications that will require a dyno tune.

Take that money you're planning on a dyno tune, buy a 2nd set of used cams, send those off, and install them, and sell the stock cams.

You'll get more bang for your buck that way.
I strongly disagree. There's so much to be gained from a tune. I'm even stocker than he is and I'm glad mine is tuned. The low speed lurch is gone. Fuel economy is up. The engine isn't knocking itself to death on the stock timing map. Responsiveness is up.

Not to mention that the stock timing and fueling maps top out just barely above the load that a stock car can hit. Intake, headers, and HFC, and you're way above the top of the table.
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Old 02-27-2008, 06:30 PM   #21
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Delta has cams in stock now so you dont need to take your cams out and send them in, no down time except for install day.

just a FYI


Josh
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Old 02-27-2008, 06:49 PM   #22
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cams just doesn't seem like a good option for me at the moment. thats all. i'd like to do them in the future.

plus i was going to tune for 91 gas also.
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Old 02-27-2008, 08:32 PM   #23
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OK, I'm glad this thread popped up. I'm familiar with Turbo's being tuned (having AP, hydra, ecutek, etc. and then having someone fine tune for every bolt on and what not). How does N/A tuning work? Do you need some sort of ECU management like PP6 first before someone tune's it? The I-Speed reflash is the most attractive to me, but I'd rather have a tune for the specific mods I have.

Thanks
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Old 02-27-2008, 09:12 PM   #24
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as far as i'm aware. its a reflash. using enguinity or however you spell it
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Old 02-27-2008, 09:28 PM   #25
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What's all this talk about money and stuff.

RomRaider/Enginuity is free to use.

The cable is the only thing that costs money. Unless you don't have a laptop...
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