Question

[TunerDSM95]

hey does porting the stock 4g64 head have any real gains with stock cam an springs just woundering cus my home boy just got a job at a shop an i could get a good deal on it if i choose to do it just woundering if it is won't the time 8)

[SuperGALANT]

well it helps if u have supporting mods.. if u have a cold air intake.. some headers, long or short..(stock isnt too bad in our case) and you would also want a good 60 mm t/b.. then porting would help more flow..
even if ur stock, it may be worth your time, how much are they charging you?

[peanotation]

it'd be kind of a waste of money IMO, do the dohc swap for more meaningful, potent power

[SuperGALANT]

<div class='quotetop'>QUOTE(peanotation)</div><div class='quotemain'>it'd be kind of a waste of money IMO, do the dohc swap for more meaningful, potent power</div>

yea that would be alot more reasonable, but not everyone can switch over an ignition system from distributer to coil packs..

[seth98esT]

Pft, thats probably the easiest part of the swap

Unles you mean emmissions/inspection wise.

IMO if you were planning on taking off the SOHC head to get it ported, you may as well do the DOHC swap as you already have the head off and its not a whole lot more work and will see more gains with a DOHC vs a ported SOHC.

If you want to stay N/A, you should do a DOHC swap, do some head work, port/polish the head, 3/5 angle valve job with larger valves, titanium springs/retainers, get more aggressive camshafts, adjustable cam gears, the works. For fuel, stock injectors would be fine, but a Walbro 190/AFRP would help.

Or just a stock DOHC head will be a noticeable gain vs stock SOHC.

[djmtz263306]

does any1 have dyno slips from the dohc swap on the 4g64 block

[seth98esT]

Not from my knowledge, but think of it this way. A 94 GS DOHC 4g64 motor puts out 160hp and 160ftlbs. The SOHC has 141hp and 148hp, so theres a gain right there.

Basically those are peak gains, with a DOHC head, you would be making more power at every RPM range vs the SOHC.

[TunerDSM95]

oh thanks for the comments but my plan was to sohc an the basics (I.H.E)
an then run a 50 shot SOME TIMES but the mod i want to do is the manual swap why bolt the DOHC to a auto but i may consider the swap later

[Proto]

<div class='quotetop'>QUOTE(djmtz263306)</div><div class='quotemain'>does any1 have dyno slips from the dohc swap on the 4g64 block</div>

once i replace my clutch/flywheel im heading to MD Performance to hit the dyno.

[98ACR]

I thought the P&P was a pretty good mod esp with a ported IM and 60mm TB. I also have a cone filter w/ mas adapter, and Flowmaster muffler. I felt a very noticible increase in power and fuel economy. I still need to do some dyno testing/track time to see exactly where I stand, but I'd place my guess at 130 whp and 16.7 in the 1/4.

A common misconception is that the DOHC GS galant made more power becuase of the head....WRONG it's in the more agressive ECU and larger TB. Flow charasteristics between the SOHC and DOHC head are similar enough to make the difference inconsequential. Meh, it's a good bucks-down mod

[4-G-rim]

I say go for it man....a SOHC can make good power. The main advantage a DOHC has over a SOHC is a broader option for tuning timing since you have 2 seperate cams controlling the intake and exhaust.

[TunerDSM95]

yeah i think i will go thru with it but now i have to find a 60 TB any body got one for sell or can i get one at the junk yard form an eclipse?

[Sleepervr-4]

<div class='quotetop'>QUOTE(TunerDSM95)</div><div class='quotemain'>yeah i think i will go thru with it but now i have to find a 60 TB any body got one for sell or can i get one at the junk yard form an eclipse?</div>

seth is selling one https://www.thegalantcenter.org/viewt...pic.php?t=49913

[98ACR]

<div class='quotetop'>QUOTE(TunerDSM95)</div><div class='quotemain'>yeah i think i will go thru with it but now i have to find a 60 TB any body got one for sell or can i get one at the junk yard form an eclipse?</div>

I've got two of them lying around in various states of complete-ness. Mine are set up for N/A use though, if you plan to go turbo you'll want one without the molded-in inlet neck. lemme know if you want one.

[SuperGALANT]

i want a 60 mm tb .. how complete are they?

[DOHCstunr]

<div class='quotetop'>QUOTE(98ACR)</div><div class='quotemain'>
A common misconception is that the DOHC GS galant made more power becuase of the head....WRONG it's in the more agressive ECU and larger TB. Flow charasteristics between the SOHC and DOHC head are similar enough to make the difference inconsequential. Meh, it's a good bucks-down mod</div>
i'll have to disagree with that.

yes the ecu having much more aggressive timing and knock dependant advance/retard mkes oodles of power, and yes the throttle plate helps flow,

as does the much larger intake ports, the better entry angle into the combustion chamber, the more aggressive cam profile'S

but sorry, with a SOHC you are committed to a more narrow volumetric efficiency range.
you are either making power up high, in the middle, or down low. you can mildly make power in two of those ranges but not all three on one tune.

with the dohc, it carries amuch wider volumetric efficiency range.
making more power across a wider rpm range.

its no secret that the sohc has no business revving over 4500 because there is no power to be made up there from the asthmatic setup.

but on the dohc it does make power nearly to its 6300 rpm redline
(i usually shifted about 5700 cause thats where the pull fades)

and i'm only speaking from a stock tune.

with better timing control, and a more aggressive set of cams you could make at least 15-25 peak hp up there. and with some adjsutable cam gears, you could spread that out by dialing in the overlap.

other factors are there is more lightning coming out of the distributorless coilpacks that go with the dohc setup.


finally on a mechanical note, when you go dohc, you end up with a smaller cylinder head dish, which decreases combustion chamber volume and increases compression ratio.

[TunerDSM95]

wow well with all that said i have made up my mind sorry but i have found a new car i dream car which as soon as the galant gives me a problem more than a grand to fix its done oh an the cars i was lookin at in my area that i could both get for less than 3500 bucks are the lexus sc300 (2JZ baby) or stick with the dsm an get a 3KGT (6G72 baby) but i will paly with the galant for now an get the p&p job done an pick up a TB for N/A use an dats whats up lol thanks for all the help

[98ACR]

<div class='quotetop'>QUOTE(SuperGALANT)</div><div class='quotemain'>i want a 60 mm tb .. how complete are they?</div>

One needs a gasket between the IAC and TB proper and a TPS sensor. (the gasket is probably $5 or less from the dealer, and you re-use your TPS)

One is just a TB that's been modified for use with the Galant IAC.