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View Full Version : Bigger TMIC w.out Tune?
JohnnyWas 02-23-2006, 12:56 AM My question is pretty simple: Is it safe to run a bigger TMIC on a stage two car w.out a tune for it?
Some of you might come and say that "oh, don't do it -- money can be better spent elsewhere," but i think more efficient cooling, ability to run higher boost levels when i want to bump them up, and more agreeable pressure drop is pretty nice. Also, I know "the stock tmic can handle up to 300hp blah blah blah" but still, I think an upgraded TMIC will allow more of an advancement in hp's and overall drivability over stock. So, what I mean to say, don't flame...
brex16 02-23-2006, 01:17 AM i think the TMIC is a great choice, what EM are you using?
I think you should be fine.
PattyB69 02-23-2006, 01:19 AM Had the same question.. Here it is:
Quote:
Originally Posted by PattyB69
Davenow,
I have Cobb stage 2 right now and i recently just purchased a TXS TMIC. Can I throw that thing on without a protune? Just reset the ECU or something?
No unfortunately you most likely cant. I have known 3 people that did it, and they all had all kinds of problems.
If you had the street tuner it would be different.
The thing is you NEED to be able to modify the tune for this thing. Just slapping it on will yeild none of the gains. I mean you will obviously work the turbo less, but the faster spool will shift the tq peak left, which will put it into an area on the map that is set up agressive to try to GET TO the peak tq, which will in 99% of cases, bring in detonation problems. You wont even really see the improved spool because the map will not be set up correctly.
When you do a better intercooler, you need to be able to shift the timing around a bit and adjust the fueling to correct the A/F for the denser air charge.
brex16 02-23-2006, 01:20 AM looks like this thread is done....theres your answer!
JohnnyWas 02-23-2006, 10:46 PM looks like this thread is done....theres your answer!
yeah. wow. good answer.
guess im going to have to get tuned sometime soon :cool: .
My question is pretty simple: Is it safe to run a bigger TMIC on a stage two car w.out a tune for it?
I’m going to say yes if you just get an STi TMIC. If you go with a bar and plate design then I would def save for a tune to get the max safety and performance.
JohnnyWas 02-24-2006, 01:34 AM I’m going to say yes if you just get an STi TMIC. If you go with a bar and plate design then I would def save for a tune to get the max safety and performance.
well, i plan on going bar and plate, so yeah -- definately getting tuned
ride5000 02-24-2006, 09:16 AM primarily the issue is with the boost control system's stability. the larger ic volume will introduce a greater latency, and that in turn can/will wreak havoc with the feedback loop comprised of the MAP sensor, the ecu, and the wastegate solenoid.
yobtah 02-24-2006, 09:28 AM Had the same question.. Here it is:
Quote:
Originally Posted by PattyB69
Davenow,
I have Cobb stage 2 right now and i recently just purchased a TXS TMIC. Can I throw that thing on without a protune? Just reset the ECU or something?
No unfortunately you most likely cant. I have known 3 people that did it, and they all had all kinds of problems.
If you had the street tuner it would be different.
The thing is you NEED to be able to modify the tune for this thing. Just slapping it on will yeild none of the gains. I mean you will obviously work the turbo less, but the faster spool will shift the tq peak left, which will put it into an area on the map that is set up agressive to try to GET TO the peak tq, which will in 99% of cases, bring in detonation problems. You wont even really see the improved spool because the map will not be set up correctly.
When you do a better intercooler, you need to be able to shift the timing around a bit and adjust the fueling to correct the A/F for the denser air charge.
I'm not sure that makes sense. If you switch to a slightly bigger TMIC, how will you get faster spool? How will you "work the turbo less"? Because the larger IC has more volume, I'd think spool would be slightly slower (shifting the power curve slightly to the right), but once "full", I wouldn't think there would be much difference. Intake air will be cooler (that's the point of the change), but your car runs reasonably well on 90-degree days and on 20-degree days, right? Seems like the air temperature and density changes would be within the ECU's ability to adjust.
Here's the reason I say that: I have a 2003 WRX at Cobb stage 2. About a month ago, I got a ProTune from Doug from TopSpeed. A few other WRX owners and I asked him about switching to a US STi TMIC. He said it's not necessary to get tuned again, and he'd expect a stage 2 or ProTuned car to make 10 to 15 more horsepower with the bigger IC. Basically he said the larger cooling capacity of the STi TMIC is beneficial. He also said spool might be slightly slower, but not very much. In general, he seemed realistic about performance gains from various aftermarket parts, so I'm inclined to trust his advice.
IndyRacer 02-24-2006, 09:52 AM ^ I think you may get different answers depending on which TMIC you swap to. Adding a Sti TMIC probably doesn't change the spool up and overall boost characteristics very much because it is just a larger version of the same core, so similar pressure drop. I think the issue would arise when switching to a bar and plate TMIC. Here your pressure drop should be significantly reduced, which means the turbo can build boost quicker and work more efficiently.
I don't personally have any data to relay, but based on what I have read, a good bar and plate TMIC should have about 2 psi less pressure drop than the factory core at 15 psi boost. That means that your turbo needs to produce 2 psi less total pressure to achieve the same peak boost value. The difference is smaller at lower boost values, but still there. So as your turbo begins to spool, a freer flowing TMIC will allow more of the boost to reach the engine, and less be wasted on inefficiency in the IC.
elsanto 02-24-2006, 10:25 AM as long as you keep an eye on your egt/boost levels you will be fine, i mean obviously get retuned eventually but id say hold off till you get that turbo.. the stock ecu is great at adapting to new mods.
JohnnyWas 02-24-2006, 11:13 AM Basically he said the larger cooling capacity of the STi TMIC is beneficial. He also said spool might be slightly slower, but not very much. In general, he seemed realistic about performance gains from various aftermarket parts, so I'm inclined to trust his advice.
This is probably so because it's a similar core design to the stock IC: not a huge bar and plate design.
I would want to upgrade to a Hyperflow or something of that nature with a good BP design for maximum cooling efficiency.
imma_stocker 02-24-2006, 05:39 PM my 02wrx is also at stage2 and i'm in NEED of a new tmic. i say need because i stripped the bolt hole where the y-pipe connects to my stock tmic, boooo for Waco not having anyone that can rethread this thing. also, i would replace it with a used wrx tmic, but y? :) i've been waiting for a reason to replace it and a friggin hole is good enuf.
btw, can anybody tell me how I can fix this? money's kinda tight for me and $300 is harsh.
eatus ravenous 02-24-2006, 08:35 PM my 02wrx is also at stage2 and i'm in NEED of a new tmic. i say need because i stripped the bolt hole where the y-pipe connects to my stock tmic, boooo for Waco not having anyone that can rethread this thing. also, i would replace it with a used wrx tmic, but y? :) i've been waiting for a reason to replace it and a friggin hole is good enuf.
btw, can anybody tell me how I can fix this? money's kinda tight for me and $300 is harsh.
two ways to fix.
one is to helicoil it , that is a thread replacment tool that is easy to use ask at any good parts store...
second is JBweld (kinda hack ) but works in a pinch mix up the JBweld and insert into the hole leaving some space for the bolt. then spray your bolt with gobs of silicone spray then jently thread in the bolt let sit for a couple seconds and remove let the JBweld sit for a half hour and rethread in your bolt pretty tight and let sit overnight and your done just retighten in the morning
imma_stocker 02-24-2006, 08:49 PM what is helicoil? i don't know if i want to JBWeld it haha. everytime i've used it, something bad happens. should home depot have helicoil? or autozone or advanced auto parts?
PattyB69 02-24-2006, 08:51 PM I'm not sure that makes sense. If you switch to a slightly bigger TMIC, how will you get faster spool? How will you "work the turbo less"? Because the larger IC has more volume, I'd think spool would be slightly slower (shifting the power curve slightly to the right), but once "full", I wouldn't think there would be much difference. Intake air will be cooler (that's the point of the change), but your car runs reasonably well on 90-degree days and on 20-degree days, right? Seems like the air temperature and density changes would be within the ECU's ability to adjust.
Here's the reason I say that: I have a 2003 WRX at Cobb stage 2. About a month ago, I got a ProTune from Doug from TopSpeed. A few other WRX owners and I asked him about switching to a US STi TMIC. He said it's not necessary to get tuned again, and he'd expect a stage 2 or ProTuned car to make 10 to 15 more horsepower with the bigger IC. Basically he said the larger cooling capacity of the STi TMIC is beneficial. He also said spool might be slightly slower, but not very much. In general, he seemed realistic about performance gains from various aftermarket parts, so I'm inclined to trust his advice.
My answer was for a large TMIC with bar and plate design like a TXS TMIC not an STI TMIC
yobtah 02-24-2006, 10:03 PM My answer was for a large TMIC with bar and plate design like a TXS TMIC not an STI TMIC
Right... but don't most "bar and plate" ICs have larger charge chambers than tube and fin ICs? If the volume of something like a TXS TMIC is larger than an STi TMIC, wouldn't spool be slower rather than faster?
You were talking about a bigger bar and plate IC, so you're right... a retune is probably more likely necessary than with an STi TMIC. I'm just not so sure about the faster spool.
Crazykev 02-24-2006, 10:19 PM what is helicoil? i don't know if i want to JBWeld it haha. everytime i've used it, something bad happens. should home depot have helicoil? or autozone or advanced auto parts?
Autozone, Advanced, NAPA or any other parts store will hav a helicoil. It is a kit that comes with a die to cut new threads into whatever, then you run in a coil to replace the threads. I think you need a 6mm, but just take the bolt so you can make sure.
imma_stocker 02-24-2006, 11:31 PM haha i found the helicoil m8x1.25. problem now is that i need a drill to use it. SON OF A ........ nu gou.
helicoil pack M8x1.25: $30
21/64 drill bit: $10
renting drill tomorrow when i need it today: $X
knowing i should have just bought a new better intercooler: priceless
at least i know what it sounds like when the y-pipe has a nasty leak at the i/c. tie between this and Supra death whine
Devil27 02-25-2006, 02:32 AM I was wondering the same thing would that throw anything off by having a bigger tmic installed. I have a TBE and will have a gutted up pipe installed sunday, and I planned on getting a turboxs tmic, then later getting an ecutek reflash. I only want the tmic now so when I end up going with a vf34 setup, I'll already have it.
WRXRallyBlue 03-27-2006, 05:23 AM Right... but don't most "bar and plate" ICs have larger charge chambers than tube and fin ICs? If the volume of something like a TXS TMIC is larger than an STi TMIC, wouldn't spool be slower rather than faster?
You were talking about a bigger bar and plate IC, so you're right... a retune is probably more likely necessary than with an STi TMIC. I'm just not so sure about the faster spool.
The bar and plate intercoolers are larger, yes, but they have significantly less pressure drop - especially when compared to the stock wrx or sti intercoolers which have relatively high pressure drop ~3psi. If there is less pressure drop then there is less time before you reach your peak.
Imagine your target is 15.0 psi.
The stock i/c at 15.0 psi has a 3.0 psi pressure drop. So you'd have to wait for the turbo to spool up to 18.0 psi to actually achieve 15.0 psi.
Aftermarket i/c at 15.0 psi has a .2 psi pressure drop. So you'd only have to wait for the turbo to spool up to 15.2 psi to actually achieve 15.0 psi.
Not exact science, just gives a better idea of what's going on.
Anyone feel free to correct me if I err.
ride5000 03-27-2006, 08:58 AM just to clarify, a pressure drop across the core for a given boost pressure is absolutely meaningless.
pressure drops occur with mass flow rates across restrictions... ie, 300g/s = 2psi drop
Need BB 03-27-2006, 03:59 PM Well does it make sense to get a bigger IC? Will a bigger IC add 15hp?
darksands 03-27-2006, 09:31 PM The purpose of an intercooler is to cool the charged air entering the engine. The way an intercooler creates more power is by cooling the charged air. The cold air generates more power so... would I be correct by saying that an intercooler doesnt have a specific HP increase rating?
An intercooler with dry ice on it can possibly generate 15 more hp on a hot day.
imma_stocker 03-28-2006, 12:54 AM An intercooler with dry ice on it can possibly generate 15 more hp on a hot day.
finally, someone else thinks dry ice rocks the boat with a tmic. y has nobody listened to me? oh well, i guess its cuz i'm young and inexperienced.
if you want to kinda know what a bigger tmic should feel like, drive your car til it's warmed up, then throw a brick of dry ice on the tmic and drive some more. or toss a cup of ice on the i/c and drive. but with regular ice you will get nasty heatsoak after the ice turns into warm/hot water until it evaporates. dry ice goes directly to gas phase so no wet i/c and no super heatsoak.
WRXRallyBlue 03-28-2006, 01:01 AM I ran the 1/4 once with a bag of ice on the i/c. Made a significant difference, incredibly, even with the bag covering almost half of the i/c.
imma_stocker 03-28-2006, 06:00 PM glad you found a little trick that works the way you want. i've already started saving up for a bigger TMIC and then i'm gonna throw ice onto that when getting tuned to see if there is any actual gain in performance. be patient tho, i'm a college student, and baylor is expensive.
darksands 03-28-2006, 09:41 PM Baylor has so HHOTT girls. I went there for a seminar once and I was :eek: the whole time. To bad the area is pretty dry.
imma_stocker 03-29-2006, 12:58 AM nothing is dry. nowhere is dry. thats y i had to take a little over a year off back at comm college in houston. hahaha loads of fun and ....memories??
i hope we're talking about the same kinda dry, otherwise i feel really stupid.
Baylor SKI team anyone(dilation=> :rolleyes: )? how bout the GREENs club :huh: ? BAR fights :confused: ? etc... :lol: :lol: like i said, nowhere is dry, especially Baylor. rich kids in a pretty ghetto have nothing better to do than pay me :D .
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