so it’s a 4cy scion tc. is a p/p worth it for me, are the gains worth the expense…and no i wouldn’t diy that.
i am planning to go with the s/c sometime soon, but i figure if the head work is to be done, it should be done before…for easier access, right? i guess the timing isn’t a big issue since i plan to have the car for a long time and don’t mind doing the project in phases.
but then after reading some of the posts here i’m like…is it even worth it in my 4 banger camry engine?
9 times out of 10 there are better places to spend your money. For some engines and builds, it’s completely worth it. For a mostly stock TC it won’t be.
I’d save the money on the port and polish and get all the supporting things you’ll need for the s/c done first. Intake, exhaust, and maybe a better clutch.Then find out whether bigger injectors and engine management is needed for the s/c. I don’t believe they are, but I haven’t really researched it.
I also think the tC’s look a whole lot better with a mild drop too so maybe look into a suspension.
dezod would be able to give you a very good idea on if theres ANY use for doing P&P work
but my uneducated guess would be that there little to no improving on the head / manifolds that would be cost effective to HAVE done
but on the flip side, if you were doing it yourself, theres always this or that that you can clean up a little bit, almost every intake ive had off of my own or a friends vehical, ive hit with a sandpaper roll or a flapper wheel, simply because its a “free mod” even if you dont get any real gain out of it
you guys are right about the importance of goals…i should have mentioned that. to expand on a few of the questions.
sorry, forgot to mention i have widened exhaust and downpipe installed in anticipation…haven’t bit the bullet yet and removed the cats. not sure that’s what i want to do yet. i haven’t done an intake because apparently only 1 works with the s/c without ghetto-modding and i don’t want to throw away a new one after the s/c install.
struts, sways i did a couple of months ago. shocks and drop? the car has only got 10k miles on it and honestly i think the drop is decent and don’t want to scrape on mcdonalds driveways. when the shocks go, maybe then i’ll upgrade. but i don’t think i’ll drop it at this point.
regarding the question about the kit: the s/c comes with injectors and an ecm map reflash.
so back to goal. i think realistically i’d like to be in the 250whp range at the end of this…but i’d like to do it as clean and efficiently as possible. to me efficient is both economical and reliable power…legal and CARB…yes that would be my preference, but i’m not saying you can’t twist my arm.
i think the s/c and upgraded pulley should get me to around 200-210ish.
i guess what i am hearing from you guys is that a p/p would not be worth it in this engine?
if you are planning on staying NA, then P&P will be of some help… If you are planning on going forced induction, i’d only do it if you are really looking to squeeze every last drop out of it. It would be more noticeable on an NA car…
Porting and polishing a head is an art based on science.
It would be worth it to you or anyone to clean up casting flaws and round sharp edges in a port to promote laminar flow since the fuel is not injected until (if not damn close) the intake valve.
To answer your question. It is worth it as an engine is an air pump, the less restriction to flow the better. However. In todays modern fuel injected engines port shape and design have been carefully calculated to provide good velocity at low engine speeds and promote turbulance to keep the air moving. The end results of this are a smooth driving car and fuel economy. While you do not need large ports to make power, you do need properly flowing ports, Do not augment the design, just clean it up. Smooth and round sharp edges or anywhere air needs to make a drastic change in direction. Remove casting flash. You can benefit by polishing the exhaust side completely with metal polish after an extensive polishing with a rough to light grit assortment of cartridge rolls. This will help prevent carbon build up as a by product of combustion. You will result in very smooth exhaust runners that are almost mirror like. Very nice.
If you have no way to accomodate for this additional air flow, ie tuning capabilities you will not see the benefits too much. You may notice a few extra horsepower accross the board if done right but the true benefits will show themselves if all other restrictions in breathing are removed and you can then alter fuel and timing to compensate for changes in breathing. Then and only then will you be able to take full advantage of what you have paid for.
ok, so now i am hearing from you guys that it ‘may’ be worth it.
but i was told recently that pnp would provide minimal hp, and that the stock ecm could account for the change. carnut, it sounds like you are saying i need management after a pnp?
plus when people say, ‘squeeze every last ounce’, sounds to me like single digit returns…realistically, what would be the expected increase on this 4 cylinder with boost?
Your are 100% correct, but it does come down to app specific technique. For example, Honda heads are pretty stingy and like little to no modifications, but will yeild gains. Back angles and mild ports typically lead to good flow. We scooped 22cfm of additional air flow on a 03 Civic head from .300 to .350. Pretty impressive if you ask me.
I will post some flow test results once we get them on the tC. That head is next.
Tuning with ANY modification will help yeild the most out of it. These OBD2 ECUs are so hung up on being emissions friendly, they do not care to make optimal performance self changes when they are present. So you need to intervene.
P.S.-I am workin on a VERY nice EMS for the tC that will be done shortly.
Um, this is why i said it is an art based on science. I have ported many cylinder heads and each one has its “app specific” technique…its called working with the port design and not changing it because unless you have hours on the flow bench odds are your going to ruin flow rather than help it.
i didnt read anything, but i was todl by a few major head builders in hondas, that a sick 3 angle valve job will see better gains over a pnp, but combined is the best. i was also told (not saying its true), anyone can make a valve flow when its opened fully, but it takes a real science to make it flow amazing when that valve first cracks open
I know. I am not discrediting you what-so-ever there chief. Agreeing and supplimenting to your material. No need to get offensive.
Well, I can assure you on our Civic app, we have about 7 hours overall on the bench. Pete is astounding with this stuff. He is truly an OG in the game.
Alot of companies & shops will tell You that their Acme 2.0L head will flow 280cfm @ 0.60". However, if they only flow 87 cfm @ 0.40" lift, the work will do You little to no good.
Peak airflow is a nice number to look at, but You want the best volume over the range of the valve event. When looking at a head flow chart, You want a broad slope, not really a peak.
Also, Your valves can flow 1100 cfm, but if You stock intake is only letting 50 cfm @ full vac, then You’re wasting Your money.
Look for a shop / company that offers a nice broad flow chart for the head, as well as one with an intake/head combo.
It depends on alot of things. unless ur going all out or can get a real good deal by a professional with a flow bench, Id say dont get it. Alot of heads now a days are pretty efficient from the factory. In most cases you will not feel any difference from a butt-dyno.
Alot of machinists have different techniques and theories out of getting maximum efficiency. If you are still interested then here are some good reads that I found year back when was doing my head: