200hp I4 Solara.....is it possible?

[gnegroni]

trade in your i4 for a v6.

+1....

+2....



I'm pulling-off on a lot of cars that are SUPPOSED to be quicker than my gen 2 Solara... I feel pretty good about this setup, and I'm not done yet. One VERY IMPORTANT part of performance that gets missed by heavily HORSEPOWER focused tuners, is the importance of TORQUE for truly streetable power that is balanced and delivers satisfying "PULL" when you want it. Ultimately, as cliche as it is.... there is no replacement for displacement.

That having been said... you can gain some good torque from compression bump and a good intake/exhaust setup coupled with some good tuning in a N/A motor... even if you stick with the 4.

(By "good torque", I am meaning several points... perhaps low teens. This, along with the improved RESPONSIVENESS of a motor that breathes better... and it can become a noticable gain...)


-crisp

Think those tC 11.0:1 pistons would do a good job then? I've heard that high compression engines suffer some, told more than a low boost turboed engine. Is that true?

[krawzyazn]

I have some spare parts forsale

head cams and intake manifold with throttle body

[crispone]

Think those tC 11.0:1 pistons would do a good job then? I've heard that high compression engines suffer some, told more than a low boost turboed engine. Is that true?

Not sure I follow... are you meaning using the tC pistons in a Solara? BWAAAHHHHHHhhhh....) As for high compression engines "suffering some"... are you meaning in terms of "durability", or "performance"? ...more than low boost turboed engines... are you meaning in terms of a lower compression engine being less "hard" on the motor... OR

are you meaning the "absolute compression" levels in a normally aspirated HIGH compression engine being the cause of "suffering" (performance or durability or both) compared to the "absolute compression" level in a low compression engine with low boost levels?

If it is the LATTER, then I would say "quantifiably yes".


With respect to the "absolute compression", I believe the INDUCTED engine may still likely be higher, but by virtue of the "80/20" rule, wherein 80% (or more) of the time is spent "OFF BOOST" in the turboed engine, wherein the motor is really "loafing along" and only 20% (or less) of the time being BLOWN FORCEFULLY to elevate the compression in the engine wherein forces greatly EXCEED the high compression normally aspirated engine which runs at a high compression/force level 100% of the time... an opportunity to support the argument exists, wherein you could say the "high strung, high compression" engine is expending more wear causing forces as an overall ratio of "time at force"... or... as a leveled average force expended over that of the "low boost-low compression" engine... for that matter, to a certain point, (a threshold which is variable with respect to the DEGREE of high compression in a NA engine), this may even apply with a MODERATELY boosted engine as well....


or something like that... maybe.



-crisp

[crispone]

EDIT --> double posted by beer...

[gnegroni]

EDIT --> double posted by beer...

Thank you for the explanation crispone. I guess what I was told was something more fitting to your 80/20 explanation. High compression will always be there on the NA engine whereas on the turbo, you would only see those similar forces applied when boosting.

Sorry for the limping message...kinda sucky to feel drunk without having any alcohol. Working for 15 hours straight (white chocolate kitkat for a 1 min lunch) does that to you. I'm not sure I'm making any sense still, after sleeping 8 hours.

[crispone]

^^^ Yes, yes.... however, I wouldn't be "fooled" by the statement "similar forces".... the INDUCTED engine is USUALLY going to see MUCH HIGHER forces (with respect to PRESSURES) in the SQUISH AREA when running under boost, EVEN if the engine is set up with a LOW compression to start with. HIGHER boost applications achieve outright ASTRONOMICAL pressures in the cylinder... hence, the HUGE gains in power. Higher power means higher heat. The enemy is not inherent to HOW HIGH your COMPRESSION is, be it BOOSTED or NORMALLY ASPIRATED... the enemy is HEAT. If you can effectively mitigate the HEAT in your engine, you can similarly mitigate the FORCES of WEAR and TEAR on the engine and create a more durable machine EVEN under HIGH COMPRESSION or HIGH BOOST applications.

It's ALL relative. Case in point, there are diesel semi engines putting out ASTOUNDING boost levels, 60, 80, 100, and MORE psi boost, yet designed in a manner so as to achieve hundreds of thousands of miles of durability.

In the case of HIGH COMPRESSION engines, you run in to conflicting "agendas"... you may be able to achieve similar durability with EXTENSIVE cooling measures, HOWEVER, these measures often require more elaborate, (pronounced HEAVY) heat dissipating components... which are usually CONTRADICTORY to the design intent of such HIGH COMPRESSION machines... no one wants to add more weight to a performance package.


...I'm just speculating, of course...


-crisp

[gnegroni]

Just read that the 2AZ-FXE has 12.5:1 (in an Atkinson cycle engine) CR pistons...I wonder, what if...

[gnegroni]

Dunno how true this might be, but here is the link to a Scion tC with 11.1 pistons and some tunning...

http://www.clubsciontc.com/flyingcesar

[MCOjerry]

You could always harness 200 horses to your car and you're set

[gnegroni]

Wonder if it does cost more to go High Compression than turbo? ~200 hp aint that bad, and that is using 11.1 pistons...the 2AZ-FXE has 12.5 pistons...if those pistons didn't have any clearance issues, that would definitely boost HP and TQ levels way high...

[orlin03]

Figure on a minimum of 12-1500 for labor of installing the pistons, then add the price of gaskets, bearings, and pistons... plus the different cam grinds needed to make use of the compression (the stock ones would probably create serious problems with cylinder pressure)...

[gnegroni]

Orlin, r you saying some new cams might be needed?

[crispone]

^^^ Yeah... I just can't understand the approach of simply "dropping in high compression pistons" as a "common" or even "efficient" way to improve bang-for-buck. Compression increases don't JUST happen from pistons being changed out... that is usually a more ADVANCED method to get such gains... and is accompanied by VARIOUS OTHER major mods. Besides, as orlin03 points out, the LABOR ALONE is big bucks for a piston swap... and I just can't imagine a modification that involved ONLY swapping pistons?!

Am I missing something?

(Considering you MAY be able to gain compression without TOUCHING the bottom end. Pull and mill heads... cams and cam timing changes... etc...)

Finally, if you make enough of a change to your COMPRESSION to make a HORSEPOWER and TORQUE benefit that you can NOTICE... you would most DEFINITELY have to be doing some TUNING related to intake air/fuel control, etc... like a DYNO'd CP-e with remap, or something... I should think.


-crisp

[orlin03]

Very true. I once raised compression in my old 7.6 pontiac from 7.5 to 1 up to 11.75 to 1 by swapping heads (I think the old heads had 115cc chambers; the new ones had 75cc combustion chambers). While I was at it, I ported the heads and upgraded the rockers by a .15 ratio. I was hoping the added lift/duration by increasing the ratio would help the engine to run better, but I failed to think about the cam profile, which was optimized to get the most possible cylinder pressure from a low compression engine. The result was an engine that produced ungodly horsepower when cold, but flat out wouldn't run when it warmed up without retarding the timing and killing at least 70 horsepower. I had to swap to a cam with much more intake/exhaust overlap, to allow the excess pressure to bleed out through the exhaust when the engine was not at full throttle/high rpms.
The change wouldn't be as extreme in the case of the solara, which already makes decent compression, but the principles are the same. More pressure by change in combustion chamber (be it by head swap or different piston face)= faster cylinder fill, different burn rate, and different fuel requirements. The computer would have to be modified for this change. Also, like I mentioned, the labor is intense. The pistons must be accessed from beneath, by removing the oil pan, unbolting the rods, and sliding them out. If you then do the cams like you should, the top of the motor also comes off; in a sense, you have just rebuilt the engine.
There would be less involved in swapping heads. Obtaining another head would give you the least amount of downtime, as all the work could be done to it while you still drive your car. Milling the head could help, but perhaps there is a compatable head out there, originally used on a smaller engine, whith smaller chambers? Does anyone know? If there is, getting one, doing work to the ports, valves, and swapping cams would be done with little labor, and swapping it in place would be much easier than removing pistons, while increasing the pontential much more than the pistons alone would have.
All in all, I think the head swap is the best big-bang-for under the price of a turbo option, but when you get into pistons, it's a whole new ball game, and the cost issue you were trying to avoid will be beating down your door trying to collect.

[DatSRBoi]

Sorry it is impossible to make 200hp in a I4, but 300 hp is so GO GO GO GO make it happen for us