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Discussion Starter #1 (Edited)
ok, so while I have done a lot of searching, deep searching back several years with posts matter of fact, I still find myself wanting to ask this question. I'll ask the question and then give a little info. why I am hesitant and still wanting to post this.

Question: What can be done to get a stock 2.0 LNF past 300HP, say ideally 320HP/340TQ (engine). It began life with supposedly 260/260, and with the GMPP tune the car should be at 290/325 (auto has less max TQ).

I find much info. about aftermarket IC's, CAI's, HF Cat's, Cat backs, straight pipes, and tunes. However, for every one thread that talks about one benefit and added power, or perhaps a dealers statement on added power, there are posts saying it's not so, the dyno numbers aren't showing the increase, etc.

So how is one supposed to have a good handle on what they might reasonably expect from some of these upgrades other than dyno runs every time they make a change (which really isn't very telling given time/conditions changing between each dyno run)?

Beyond the GMPP tune I mentioned, I have a Hahn IC that I should install this spring. I believe that will be good for about 8-10HP peak, but more benefit with power response, power band, and avoidance of IC heatsoak and subsequent power loss.

So this might put me close to 300HP, but then what? I hear many conflicting statements about the HF cats, and I'm hesitant to put one on until our first emissions test is due, even then fearing it will cause a fail next time around. But these are said to add another 10hp or so?

CAI, most say added noise and useless, and I would agree given the huge CFM the stock intake is capable of. Maybe just a drop in K&N, but even then not sure you can count HP.

Cat back exhaust, stock looks awefully good to me (except the muffler, which appears to be another piece of reuse from another GM car but likely isn't hurting flow at all), and most say it is, just lacks nice sound. I won't bother given the price for a better sound.

Different tune? or? or?

Anybody else just trying to keep the motor stock and maximize it's potential into the lower 300's? That's what this thread is all about. No big wheel, nothing radical, just seeing what you can get with a few well placed mods. I should also mention this is strictly a street driven car for fun, not a DD, and we'd like to keep it totally stock looking. I'd like to take it to a quarter mile track one day.
 

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Check my mods below. Plus I have a 3-bar MAF sensor. I've not had it on a dyno, but a forum member told me that he has the same mods as mine, and it dyno'ed at 305HP at the wheels. No mention of torque. if you presume 15%-20% driveline loss, you can figure estimated flywheel HP. Don't know how accurate or true it was but it made me feel good about my mods. To me, the numbers are not as important to the seat of the pants feel. I don't plan any more engine mods.

But I have to say that I've gotten a lot of enjoyment, maybe even more than the HP increase, from my suspension mods, most of which were done after the engine mods. Chassis stiffeners, sway bars, BC coilovers, alignment and tires all make great improvements in handling and enjoyment.
 

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I'm with you on this one shadowfax, and I do believe it is completely possiible, I have started my quest to post 300hp with my purchase of a werks IC, and will be following Carpe's list of performance mods,somewhat, solo cat and magnaflow but probably go for GMPP tune for now until warranty runs out, then different tune possibly. I think it is awesome to pull these numbers from a 2.0 for ~$2k I am considering dyno-ing before and after for chits and giggles(if it's not to pricey?) Carpe Diem I do remember seeing that thread and of course it caught my eye as well, I'll see if I can find it.

Bert
 

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I recommend you gevr Dave at Werks a call, and Dave at DDM. They both have years of experience with just about every configuration of car and in house dyno'd. They have done hundreds of runs with cars.

DDM Dave measured 305 WHP with my car on his dyno before he removed the motor. That was with all the hardware upgrades, GMPP tune which he tweaked personally.
 

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Catless downpipe, FMIC upgrade, and a GOOD 20-21 psi tune - DONE! That's all you need. The dyno numbers in my sig are through a stock airbox, and I'm running an EFR turbo now also through the stock airbox. Yes, an upgrade may make for less restricted flow, but it's not a limiting factor yet.

I can't emphasize enough how much the tune matters. You can make safe decent power on relatively low boost pressure (20-22psi) if you know what your doing.
 

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I would start with the IC. However, without a HFC and exhaust I'm wondering if putting a new bigger IC would help. I have HFC, solo street race exhaust and a Fujita CAI, but a stock IC.... But if you go that way, either tweak the GMPP tune or get a new one. You should easily be over 300hp. I think I'm right around 310... You really don't need a CAI from what I've read....it just adds noise. It magnifies the BOV we have to give you that ppssssshhhhh sound. Then after all of the above is done, it's time to start thinking about a different turbo. According to a guy here at work that's been drag racing turbo cars for 20 years, these little turbos become useless after about 22psi. Any extra psi's are just lost and you risk damaging the turbo.

On a side note, I always thought the purpose of a HFC was so cars could still pass emissions.... hmmmmm.....
 

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Shadofax,
I think where I am at is where you want to be....
GXP 260HP
GMPP tune 30HP
Solo GXP Mach exhaust and Hi Flow Cat ... My guess is 20hp combined
Adds up to 310 HP. I can tell you that she is fast and at this point I am not planning anymore mechanical mods as she is as fast I can handle.
In addition I have the GMPP CAI ( sound and looks) and DDM chrome LNF pipes (looks).
If you go with the set up I have I think you will be very happy. I also did the DDM suspension trifecta...LV brace, probeam and backbone which I would also recommend.

I am in no way mechanical so when I did the above I went with mods that would not void my GM warranty ( still got 6 months on that) and were tried and tested by the Forum members. Like you, I did a lot of digging through old threads to research these mods.

Bottom line...my Sol is faster than I really need now ( love it) and I notice a major difference from the stock 260HP and she sounds awesome!!!
Hope this helps!:thumbs:
 

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Suggest first reading WSPOHN: http://www.solsticeforum.com/forum/f63/lnf-mod-primer-60166/

Bottom line; to get more HP/TQ than the GMPP option (regardless of hardware) you have to go with an aftermarket tune (HPTuners, Trifecta) due to the Engine Control Module (ECM) software parameters having to be changed/altered.

Otherwise, regardless of what initial gains from aftermarket hardware is installed the factory ECM will learn back down to what the OEM parameters allow or are set at.
 

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Discussion Starter #11
I would start with the IC. However, without a HFC and exhaust I'm wondering if putting a new bigger IC would help. I have HFC, solo street race exhaust and a Fujita CAI, but a stock IC.... But if you go that way, either tweak the GMPP tune or get a new one. You should easily be over 300hp. I think I'm right around 310... You really don't need a CAI from what I've read....it just adds noise. It magnifies the BOV we have to give you that ppssssshhhhh sound. Then after all of the above is done, it's time to start thinking about a different turbo. According to a guy here at work that's been drag racing turbo cars for 20 years, these little turbos become useless after about 22psi. Any extra psi's are just lost and you risk damaging the turbo.

On a side note, I always thought the purpose of a HFC was so cars could still pass emissions.... hmmmmm.....
yea, your first item in bold is case in point, threads I've read seem to suggest that it's perfectly fine to go larger IC as your first upgrade after a tune, matter of fact that's probably the preference (as several seemed to think that HFC did very little and the claims of HP they were skeptical of). But yes, a HFC you'd think would still pass emissions in any state, you'd think. It's aftermarket, so don't consider passing a given, I don't see any suppliers of these guaranteeing it will pass emissions, so I'd like to ensure it passes on the stock one before going to this mod.

Catless downpipe, FMIC upgrade, and a GOOD 20-21 psi tune - DONE! That's all you need. The dyno numbers in my sig are through a stock airbox, and I'm running an EFR turbo now also through the stock airbox. Yes, an upgrade may make for less restricted flow, but it's not a limiting factor yet.

I can't emphasize enough how much the tune matters. You can make safe decent power on relatively low boost pressure (20-22psi) if you know what your doing.
The catless downpipe is a no go with emissions, and a GOOD tune? Is that to say there are BAD tunes out there? The car sees 21-22 psi easily during summer (I briefly have seen 23psi).

Check my mods below. Plus I have a 3-bar MAF sensor. I've not had it on a dyno, but a forum member told me that he has the same mods as mine, and it dyno'ed at 305HP at the wheels. No mention of torque. if you presume 15%-20% driveline loss, you can figure estimated flywheel HP. Don't know how accurate or true it was but it made me feel good about my mods. To me, the numbers are not as important to the seat of the pants feel. I don't plan any more engine mods.

But I have to say that I've gotten a lot of enjoyment, maybe even more that HP increase, from my suspension mods, most of which were done after the engine mods. Chassis stiffeners, sway bars, BC coilovers, alignment and tires all make great improvements in handling and enjoyment.
3 bar MAF sensor, this helps you how, have not seen this discussed much?

I recommend you gevr Dave at Werks a call, and Dave at DDM. They both have years of eerience with just about every configuration of car and in house dyno'd. They have done hundreds of runs with cars.

DDM Dave measured 305 WHP with my car on his dyno before healed the motor. That was with all the hardware upgrades, GMPP tune which he tweaked personally.
That's interesting. I would be interested in modifying the GMPP tune that is on there if there are some parameters that perhaps GM has kept conservative and could be holding back some power?

Shadofax,
I think where I am at is where you want to be....
GXP 260HP
GMPP tune 30HP
Solo GXP Mach exhaust and Hi Flow Cat ... My guess is 20hp combined
Adds up to 310 HP. I can tell you that she is fast and at this point I am not planning anymore mechanical mods as she is as fast I can handle.
In addition I have the GMPP CAI ( sound and looks) and DDM chrome LNF pipes (looks).
If you go with the set up I have I think you will be very happy. I also did the DDM suspension trifecta...LV brace, probeam and backbone which I would also recommend.

I am in no way mechanical so when I did the above I went with mods that would not void my GM warranty ( still got 6 months on that) and were tried and tested by the Forum members. Like you, I did a lot of digging through old threads to research these mods.

Bottom line...my Sol is faster than I really need now ( love it) and I notice a major difference from the stock 260HP and she sounds awesome!!!
Hope this helps!:thumbs:
This is case in point....I guess I really have to dyno before and after with the IC mod and then a HFC to really see the difference numerically. And because it will be done at different times the circumstances will not be exactly the same. I just really don't want to be guessing about HP adds. Most would agree that the tunes are providing in the 30HP+ range of power improvement, but do you really think you followed that up with +20HP from your HFC and the exhaust? Like you said though she is fast. Who knows?

On a side note, the only handling stuff I'd likely do beyond the stuff that is already on the car (see sig) is a change of tires to some Michelin's, and perhaps one day the GMPP coils.
 

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Discussion Starter #12
Suggest first reading WSPOHN: http://www.solsticeforum.com/forum/f63/lnf-mod-primer-60166/

Bottom line; to get more HP/TQ than the GMPP option (regardless of hardware) you have to go with an aftermarket tune (HPTuners, Trifecta) due to the Engine Control Module (ECM) software parameters having to be changed/altered.

Otherwise, regardless of what initial gains from aftermarket hardware is installed the factory ECM will learn back down to what the OEM parameters allow or are set at.
I've read that thread, however you and I seem to be interpreting it differently. I have the GMPP tune and while there are still parameters set we don't really know what they are. There is nothing in that discussion by John on post 1 that indicates the new GMPP tune will keep you right at the new HP/TQ numbers. If you read that carefully (they are kind of going back and forth in the discussion between discussing learn down on factory tune and what learn down becomes with GMPP tune), it's just stating there are still limits:

"The GMPP Turbo upgrade kit turns off the learn down portion of the torque managing program. Therefore it will not learn out add-ons such as CAI or Exhaust systems.

What most people are mistaking as learning out/Learn Down, are the safetys that are still in the software and still active. These are there to help guarentee the system is durable for the 100,000 mile warranty and parts are not damaged. There is still an overboost protection, there is still a program that is calculating what the turbine speed is and will limit boost if you approach the maximum allowable speeds.

So as an example if you change the turbo and are getting much higher boost you will engage the overboost protection. "

So if I'm reading this correctly for this discussion the limiting/learn down should be N/A, we aren't putting on big wheels here, we just want some honest power upgrades to get us above 300hp.
 

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So if I'm reading this correctly for this discussion the limiting/learn down should be N/A, we aren't putting on big wheels here, we just want some honest power upgrades to get us above 300hp.
You are reading it correctly. The GMPP will allow higher air flow and higher power from mods, but still has built in safeties to prevent engine issues that will reduce output for safety. Just where the lines are drawn we don't know, but some people seem to be able to get significantly more power with mods than the 290 BHP.

After market tunes do not need the sensors used by the GMPP, which specified those sensors simply to meet a policy of having a 30% head room capability.

Other after market tunes play around with the fuelling and ignition tables and by running closer to the 'line' than GM considered prudent, they get considerably more power.

I think that adding a high flow CAT is a good first move after your GMPP tune. Not sure the exhausts get anywhere near what is claimed on their own, but the CAT seems to be good for around 15 BHP.

Also no sure an after market IC does much - probably nothing at all on a stock tune except to delay heat sink degradation of power, which will only matter if you do back to back full throttle runs. Nonetheless, after tuning it is probably a good idea.

We now have another player producing after market intake manifolds, but they have yet to be independently verified as to result on a tuned engine. Sounds interesting though.

For what you want, I'd probably opt for an after market tune (Trifecta is one that has excellent results on stock engines), a high flow CAT, maybe IC tubes just to clean up the appearance, and if you like, also a new IC - there are several sources. Then call it a day and just drive it, probably in the low 300's for power.
 

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Trifecta. Boom, done. Your Hahn IC will be icing on the cake. This will put you above your target number so I don't know if that will be an issue or not. If I recall correctly this will be in the neighborhood of 330-340hp and upwards of 400 torque.
 

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As mentioned, the DDM trifecta is an awesome upgrade...it does not add HP but it effectively helped me put my power to the ground.

Also as said, Trifecta is the answer. Get an E85 or E47 tune as I have and you easily have 320HP without any additional modifications.
 

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I think 3-bar MAF sensor is just a typo - the upgrades area 3-bar MAP sensors.

Yes you can find bad tunes out there. They include tunes that run too little timing advance and too much boost, and also running the LNF too rich. That's not to mention the drivability issues that can occur with a poorly dialed in MAF. If you're getting an off the shelf tune, there's only so much you can expect, but a custom tune should have no problem meeting your needs. For example, with enough iterations, Trifecta can get the job done.
 

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My set up right now is:

GMS1
KN filter
Magnaflow catback

By the end of April my setup will be:

HPT tune(terminator2)
KN filter
Magnaflow cat back
Werks cooler
Werks catted downpipe

I am told normal results for a custom 93 tune will be 50hp/80tq over gms1. I would dyno, but I don't want to spend an extra $300 for before/after dyno runs. I will however log some 60-100mph. That will at least indicate the gains. As for mods choice I just wanted to gain a little extra efficiency, gain a broader power band and a good exhaust note. Thing that bugs me about GMS1 is there are days it pulls strong and days it feels flat. I think the pcm is still limiting the car quite a bit.

Check out some LNF dyno charts

Here are some dynos with mod lists from the Cobalt forum. Go down a little bit to:

http://www.cobaltss.net/forums/dyno-results-170/new-official-dyno-thread-2012-a-272372/

2.0 T/C - K04 Power!!

K04 is the stock turbo. You'll see 300whp is possible with GMS1 with bolt ons, but much more is possible with other tunes and especially e-85(e47)
 

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Discussion Starter #18 (Edited)
My set up right now is:

GMS1
KN filter
Magnaflow catback

By the end of April my setup will be:

HPT tune(terminator2)
KN filter
Magnaflow cat back
Werks cooler
Werks catted downpipe

I am told normal results for a custom 93 tune will be 50hp/80tq over gms1. I would dyno, but I don't want to spend an extra $300 for before/after dyno runs. I will however log some 60-100mph. That will at least indicate the gains. As for mods choice I just wanted to gain a little extra efficiency, gain a broader power band and a good exhaust note. Thing that bugs me about GMS1 is there are days it pulls strong and days it feels flat. I think the pcm is still limiting the car quite a bit.

Check out some LNF dyno charts

Here are some dynos with mod lists from the Cobalt forum. Go down a little bit to:

New Official Dyno Thread (2012) - Cobalt SS Network

2.0 T/C - K04 Power!!

K04 is the stock turbo. You'll see 300whp is possible with GMS1 with bolt ons, but much more is possible with other tunes and especially e-85(e47)
You bring up several interesting things. First thanks for linking to the Cobalt fourm for added info. on this. Why I didn't think about wandering around there seeing what they have going is a mystery. :willy: Though I'm not understanding all the acronyms...IC I think I got, but CD, DP? And GMS1 or GM1 is referring to stock tune? If that is the case some of those wheel HP numbers seem suspect. For instance:

19. BoostedYards86, 327whp, 384wtq, Verified Dynojet, I/CP/IC/DP/GM1, Graph


Also, thanks for actually putting some numbers out there with regard to HP increase one might see with going custom on the tune vs. the 30HP we know we are supposed to be getting with the GM tune.

One thing you didn't mention though with those numbers, those are FWD. So whenever I have seen dyno graphs you can't just relate them to our cars since there is definitely a difference in driveline loss. I'd be surprised if FWD setups see anything near a 5% loss in their WHP numbers whereas I'd guess we see in the ballpark of 10-12%, which is why their numbers always look more inflated. I doubt we see anything over 15% loss, this would be on less efficient drivelines like my bronco....sluggish automatic, and much more angularity in the driveline.

So for anyone, question on the custom tunes...I was looking at DDM's website last night and the Trifecta tune and HP Tuners.

Why do they sell both, am I understanding these offerings correctly in that Trifecta gathers your base info. (via form you fill out) makes a few tweeks and sends you the program, which you then can take with your laptop and plug into the vehicle ECM or whatever for download. Then you drive around and send back to them an updated file that gathered vehicle technical details so they can dial it in for you?

HPT on the other hand seems more for someone with much more expanded knowledge that wants to play with the parameters themselves, really making more of their own custom tune, is this accurate?
 

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Why do they sell both, am I understanding these offerings correctly in that Trifecta gathers your base info. (via form you fill out) makes a few tweeks and sends you the program, which you then can take with your laptop and plug into the vehicle ECM or whatever for download. Then you drive around and send back to them an updated file that gathered vehicle technical details so they can dial it in for you?

HPT on the other hand seems more for someone with much more expanded knowledge that wants to play with the parameters themselves, really making more of their own custom tune, is this accurate?
That's about it.

In one case you have it tuned (either canned or with feedback from a run file, which costs a bit more) or you can try it yourself. Problem is that mistakes can be expensive!

OTOH, HPT followers like a hands on do it yourself approach, which I certainly understand, and there are sites and some very experienced programmers that will (usually for a fee) help out. There is something to be said for both approaches.
 

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The Cobalt's also have electric power steering which also helps them have a little more power. There can be 15 to 30 hp difference on an dyno.
You are correct on the tune process. The 50 / 80 TQ gain is closer to stock improvement. Closer 20hp/ 30TQ vs gm tune but you will have much better throttle response and power quicker with less knock

With an E47 blend you can add approx another 30 whp and 40TQ
 
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