Sohc Power!!!

[jeff983000gt]

hey guys..i have a 98 3000gt sohc 12 valve motor..i have a full borla exhaust with downpipe and an injen intake.. i just had my heads port and polished..also..had my exhaust manifolds opened up as well as my intake manifold.. i upgraded to a 52 mm throttle body for more forced air..60 thousands was shaved off the heads increasing more compression..i also got a underdrive pulley...in the end i figure starting at 160 hp..i probly have around 210-220 hp..whats anyones opinion on upgrading to an MSD ignition? in the end im running better then a stock SL because with my compression ratio moved up to 10 instead of 8.9 i have less parts moving faster then the SL does..FINALLY A BASE MODEL 3000GT GETTING SOME POWER!!!

[Igovert500]

Okay, I'm starting by banging my head on the keyboard. ahklo2ytoi2htklnfln5932

Okay, now let's start from the top:

You don't add every manufacturer's claimed hp gains up and add that to your base hp. Dyno your car, I think you will be surprised. I doubt your 210-220 estimate. Bolt-ons and a little port and polishing rarely adds 60hp. Not to mention, if there aren't original bottlenecks or restrictions in flow, opening it up only slows velocity and is generally worthless and wont add power. The Borla NA exhaust sucks...sorry, so I hope you went with the turbo one. Borla exhausts just aren't that much of an improvement over the stock ones..so for an NA for actual improvement you want the TT exhaust.

Next, stock sohc throttle body is 54mm, so your 52mm isn't an upgrade. The DOHC TB is 60mm, is that the upgrade you are talking about? Or did you toss on some Chrysler 52mm TB, which would technically be a downgrade. And, just so we are clear, a larger throttle body does NOT equal more forced air. On the intake side, the engine is only gonna suck up the air it needs. Short of a RAM AIR effect of driving fast and having air forced into the intake, NAs don't have forced air.

Porting and polishing, that really varies from job to job, so I can't comment on it without seeing it in person, dynod before and after, or flow tested. Hope you got your money's worth. And they didn't just gut the hell out of everything. The SOHC heads really do flow poorly and there is plenty of room for improvement from what I've read, so if properly flowtested and then worked, in combination with some cams, I think there is decent room for improvement. However, the 4 valve heads of the DOHC will still flow better.

Lastly, you have zero need for an upgraded ignition. So don't waste your money.

Basically, my point is this. It is your car, do whatever you want to it, if it makes you happy. But, for the money you have already put into modding it, you could have simply just sold the 98, and bought a pre 97 that came with the DOHC and be better off that you are now. Or you could have started saving for a supercharger or done a TT conversion from used vr4 parts already. This is why I heavily suggest researching for the best ways to spend money, rather than just throwing money and parts at a car. I'm not trying to be a prick, but I just think with all the money that you most likely spent on this stuff, you could be alot faster at this point. And I also think that you are being optimistic in the results you have obtained.

[jeff983000gt]

first off..i did not add manufactors hp "claim to get gain" i put realistic gains in perspective..next..i did put turbo borla exhaust on..i agree NA ones do suck..i have one cat on the whole exhaust and one muffler for inspection reasons..otherwise im running full 2 1/2 exhaust..downpipe included..next base model throttle bodys are 49 mm..do your research..so upgrading to 52 is pretty decent..the guys who ported my heads are the best around my area..there was PLENTY of room for improvement in the heads..at least 30-40 hp gain in just head porting..so i would say with all my other upgrades i have at least another 10-20..the numbers add up..can you count???

[Igovert500]

Originally Posted by jeff983000gt

the numbers add up..can you count???

I can count, thanks for asking. I can also read rather well.

Originally Posted by jeff983000gt

next base model throttle bodys are 49 mm..do your research..so upgrading to 52 is pretty decent

See, I can read this here, where it says the SOHC throttle body is 54mm, and here, and in the other 100 or so threads on the topic. As well as in the service manual where it says 54mm. I can also read "no results" on the page I get after I run a search for '49mm' on 3si.

Let's continue, shall we. I read this and chuckled.

Originally Posted by jeff983000gt

next..i did put turbo borla exhaust on..i agree NA ones do suck..i have one cat on the whole exhaust and one muffler for inspection reasons..otherwise im running full 2 1/2 exhaust

I chuckled, because I read how the NA Borla exhaust is 2.5" splitting into twin 2" piping here, and how I read the TT Borla exhaust is 3" splitting into twin 2.5" piping here.

Weird huh??? So that must make you the only guy ever to find a full 2.5" turbo borla exhaust!?!

Originally Posted by jeff983000gt

i did not add manufactors hp "claim to get gain" i put realistic gains in perspective.

What I'm not reading is a dyno sheet, time slip, or flow test from you. So please feel free to prove me wrong.

[jeff983000gt]

actually..there was a rear section of the borla exhaust on ebay that i bought and i customized the center piping into 2.5 in piping to match up with downpipe to rear section..so yes i guess i am the only guy in the world..you are so smart..you must really have a life to do all this research for no apperent reason..and yes i appoligize i was told they were 49 mm..but i have read up to see they are 54..my mistake...

[Stealthee]

Originally Posted by jeff983000gt

hey guys..i have a 98 3000gt sohc 12 valve motor..i have a full borla exhaust with downpipe and an injen intake.. i just had my heads port and polished..also..had my exhaust manifolds opened up as well as my intake manifold.. i upgraded to a 52 mm throttle body for more forced air..60 thousands was shaved off the heads increasing more compression..i also got a underdrive pulley...in the end i figure starting at 160 hp..i probly have around 210-220 hp..whats anyones opinion on upgrading to an MSD ignition? in the end im running better then a stock SL because with my compression ratio moved up to 10 instead of 8.9 i have less parts moving faster then the SL does..FINALLY A BASE MODEL 3000GT GETTING SOME POWER!!!

Igo already tore you apart but I am going to continue.

#1 Borla MIGHT add 10hp tops at the crank. Thats more like 2 or 3 at the wheels.
#2 Downpipe can be a good solid 10 hp to the wheels.
#3 Injen intake, no power gained. On top of that you paid $170 for a piece of shit pipe that utilizes the stock elbow just because it had Injens name on it.
#4 Igo already informed you on teh port and polish. May have freed up some power but not what your thinking. Quit using Gran Turismo for power gains.
#5 Same thing as #4 on the exhaust manifolds. But no gain.
#6 The SOHC 3s came STOCK WITH A 54MM TB. End of STORY. Measure it. You downgraded.
#7 Even if you did raise the CR to 10:1 you are only looking at a max of 10 hp, IF THAT.
#8 There is NOT ONE underdrive pulley available for the SOHC. There is a lightweight and you may see 3 hp from it.
#9 Less parts moving than a DOHC makes you faster now. Buahahahahahahahahahahahahahahahahahahaha

Now you cant combine all those numbers and think you will see that sum as a total gain. You may have picked up a whopping 20 hp. You still arent in SL territory. Beating up on the ATX's doesnt count because I did that in my STOCK SOHC. Go race a MTX and get your ass handed to you. My car is far from stock now and I bet even with your mods I would still walk your ass.

And BTW you need to watch the attitude acting like know everything because OBVISOUSLY you dont know squat.

[jeff983000gt]

what are you talking about..have you checked..3sx.com for underdrive pulley for sohc..man you know your stuff huh..and seeing as how i have one on my car..thats funny..but you know more then i do..they dont make ONE in the whole world..im sorry do you know ANYTHING about porting heads??? didnt think so..porting heads alone gives 30 hp..at least..get your stuff straight..im done dealing with people on this sight who dont know what there talkin about...

[lc420]

Originally Posted by Stealthee

Igo already tore you apart but I am going to continue.

#1 Borla MIGHT add 10hp tops at the crank. Thats more like 2 or 3 at the wheels.
#2 Downpipe can be a good solid 10 hp to the wheels.
#3 Injen intake, no power gained. On top of that you paid $170 for a piece of shit pipe that utilizes the stock elbow just because it had Injens name on it.
#4 Igo already informed you on teh port and polish. May have freed up some power but not what your thinking. Quit using Gran Turismo for power gains.
#5 Same thing as #4 on the exhaust manifolds. But no gain.
#6 The SOHC 3s came STOCK WITH A 54MM TB. End of STORY. Measure it. You downgraded.
#7 Even if you did raise the CR to 10:1 you are only looking at a max of 10 hp, IF THAT.
#8 There is NOT ONE underdrive pulley available for the SOHC. There is a lightweight and you may see 3 hp from it.
#9 Less parts moving than a DOHC makes you faster now. Buahahahahahahahahahahahahahahahahahahaha

Now you cant combine all those numbers and think you will see that sum as a total gain. You may have picked up a whopping 20 hp. You still arent in SL territory. Beating up on the ATX's doesnt count because I did that in my STOCK SOHC. Go race a MTX and get your ass handed to you. My car is far from stock now and I bet even with your mods I would still walk your ass.

And BTW you need to watch the attitude acting like know everything because OBVISOUSLY you dont know squat.

hahahaha i love it! pwned!

[Stealthee]

Originally Posted by jeff983000gt

what are you talking about..have you checked..3sx.com for underdrive pulley for sohc..man you know your stuff huh..and seeing as how i have one on my car..thats funny..but you know more then i do..they dont make ONE in the whole world..im sorry do you know ANYTHING about porting heads??? didnt think so..porting heads alone gives 30 hp..at least..get your stuff straight..im done dealing with people on this sight who dont know what there talkin about...

You are the one who doesnt know what you are talking about. Go ahead look at 3sx. There is NO UNDERDRIVE PULLEY FOR THE SOHC. They do have a lightweight one but not one company makes one for the SOHC. And where the hell are you pulling the number 30hp from porting and polishing from? Your ass? Even forced induction cars have to have a massive port and polish done to see close to those numbers. NA will show a MUCH LOWER increase. On the way out dont let the door hit you where the good lord split ya. Good riddance.

[Igovert500]

Yeah recalling those numbers and websites from memory was pretty time consuming. Wish I had a better way to spend playoff game commercials. Unfortunantly, they aren't as good as Superbowl commercials...so I get bored.

So because I'm right, I have no life? Not gonna try and tell me you're getting Vtec and will be beating up on vr4s next week? Just gonna skip right to the 5th grade comebacks and leave in a huff?

As I said before, feel free to prove us wrong. Post something relevant, open up a debate, 'enlighten me'. But don't get pissed off at us because you are incorrect.

[xXxRocker5150]

Just buy the rippmods supercharger kit for the SOHC... it's basically the only real performance gain for a SOHC (besides turboing it, and IDK if anyone's done it before...).

[Linebckr49]

Originally Posted by jeff983000gt

what are you talking about..have you checked..3sx.com for underdrive pulley for sohc..man you know your stuff huh..and seeing as how i have one on my car..thats funny.

i checked 3SX.com. and i found underdrive pulleys..........for the DOHC. man, i know MY stuff. i really do.

you have one on your car? then were you able to re-use the stock accessory belts? hmm?

3SX UNDERDRIVE PULLEY. please tell me if you see the "SOHC" anywhere on that page. i may need to get my prescription changed.

3SX LIGHTWEIGHT STOCK SIZE PULLEY. this is what you have. or is it? oh, my mistake, you have the only 3SX underdrive pulley in the world for the SOHC.....right?

[Shpyder]

jeff983000GT, you've dug yourself a pretty big hole here, and your only redemption is to provide a dyno sheet to prove your power gains.

All that stuff you listed simply cannot put down that power to the wheels on its own, without juice or boost, on an NA SOHC, so +1 on the list Stealthee provided. I put an Injen intake and a 2.25" catback on my SL just because I wanted it to sound a little throatier, and I know that I probably didn't get more than 3-5 extra hp to the wheels, and that's being generous. My tired old '93 with 170,000 on the clock would still hand your butt to you despite those "upgrades" you listed. Even some turbo people get dissapointing results despite going big on upgrades on the turbo route if not matched correctly: I ran a T-28 on my spyder for a while, and it still felt like it was pushing the same air as the stocker on the same boost. You arent even turbo or nitroused, so your hp gains with purely NA upgrades will be even more limited, expecially on a SOHC.

Bench-racing and bench-dynos are usually frowned upon here at AF, and it's in your best interest to avoid them. My Spyder had a fully built drag motor done by SBR, with a ported and cammed head, high compression block, the works, and an evoIII16G turbo, among other mods. I never once claimed any hp figures on it because I never dynoed the car. All I would say is "it's faster than stock, I hope" and call it a day. Maybe youre safer doing the same, until you got that dyno slip handy...

[Twizted_3KGT]

Yeah, you can't just add up figures that the ads tell you or what you estimate...at the wheels I would say you're pushing less than 130 hp. Good luck learning the ropes.

[Morphius289]

I'm surprised this thread hasn't been closed yet.


And just a tiny little after-fact. Even with 210hp...it's still a slow SOHC. You want to mod? Save your money for a VR4.


::edit:: Found his dyno chart-