Will upgrading heads increase or decrease turbo spool times?

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Will upgrading heads increase or decrease turbo spool times?

August 27, 2012, 10:01:51 PM

I am trying to found out if a nice set of heads will quicken the spool time of a turbo. I do know from experience that upgrading heads will lower boost pressure, but I finding conflicting info regarding spool up times with better heads. Now I do know a good set of heads can net a gain of up to 100hp in certain applications; also, aluminum heads seem to resist detonation more than steel heads. Now if good heads can gain 80ish hp on an NA motor, this must also improve spooling if the engine breathes easier. I just wanna know from someone who has experience in this area, I am assuming a decent turbo grind cam can help spool also, but I also heard that the stock cam is pretty decent for turbocharging already. Just wondering where should I focus my energy this winter on the cougar.

Will upgrading heads increase or decrease turbo spool times?

Reply #1 – August 28, 2012, 12:41:33 PM

Not to dodge the basics of your question, but don't you have a 76MM Turbo with a stock S/O engine?

Will upgrading heads increase or decrease turbo spool times?

Reply #2 – August 28, 2012, 12:55:44 PM

Anytime you increase the flow of air through an engine ( another words reduce pumping losses) Your turbo will spool faster.

Note head HP increases ar hard to figure because you have flow numbers and compression numbers. 100HP gain ??????

Note Turbo cams are usually low in duration high in lift and around 112* LS. :hick:

Will upgrading heads increase or decrease turbo spool times?

Reply #3 – August 28, 2012, 03:56:18 PM

ft40P heads will flow better and have a bit more compression ratio than E6 or e7 heads,

Will upgrading heads increase or decrease turbo spool times?

Reply #4 – August 28, 2012, 08:23:39 PM

TOM,

Thanks for the answer, that is what I thought, but the local guys were trying to tell me otherwise. As for the 100hp gain, some head manufacturers claim gains of 120hp with their race ported aluminum heads. I have never seen more than 80hp gains personally (78 on my NA 347stroker with patriot heads and cam).

Not to dodge the basics of your question, but don't you have a 76MM Turbo with a stock S/O engine?

YUP, got over 6000 miles on it driving like I stole it:)
The stock S/O engine is stronger than one thinks.

Will upgrading heads increase or decrease turbo spool times?

Reply #5 – August 28, 2012, 09:53:34 PM

Quote from: canadiancarguy;396873

The stock S/O engine is stronger than one thinks.

Ah, OK.

I think Tom has you covered on the air flow question.

An additional question, to clarify what you hope to accomplish: Are you looking for an engine combination which will work well with the 76MM turbo or open to looking for a turbo which may work well with your engine (at least until it shows the limit of it's strength)?

Will upgrading heads increase or decrease turbo spool times?

Reply #6 – August 28, 2012, 10:18:13 PM

I was planning on running a stroked 351 windsor in the car sometime in the future I have one ready for tear down out of a truck. I have a T67 waiting to get rebuilt, that was what was originally in there with the turbo kit. The 76 was all that was in stock and I needed a turbo quick, it still didn't show in time for the second drag event of the year anyways.

I have a 3600-3800 stall 10inch converter coming and also a trans brake valvebody. I am planning on getting some cheap pro comp heads with 1.7 rockers and will run it with stock cam.

Will upgrading heads increase or decrease turbo spool times?

Reply #7 – August 29, 2012, 03:55:00 PM

Glad you're putting together a combo which will take advantage of the induction system and live!

I suspect the longevity of the long block is related to the considerable restriction the stock S/O engine is to the turbo. Based on the MPH of the 1/8 mile times (78 mph), it's not making a ton of power (yet).

The trans parts you've listed for upgrades will be used when you step up to the stroker, so there's no loss adding them to the current combination, as you'd buy them anyway for the next one.

The loose converter and trans brake will help get it spooled up (as much as ~120 CFM of intake head flow will allow). If it builds boost, it might be akin to pulling a pin on a grenade!

I'll offer a little unsolicited advice (no offence if you think it's whacked! It is your car & money): Save the cash on a head upgrade & rocker upgrade for the S/O and wait to buy the best heads you can afford for the stoker (think 205's: TFS or AFR).

The S/O will expire at some point anyway (maybe in a spectacular fashion, but more likely it'll just lift the heads and puke coolant everywhere), you're having fun, try to get it to live the rest of the season!

Spend the money where you'll get the biggest bang for the buck.

Will upgrading heads increase or decrease turbo spool times?

Reply #8 – August 29, 2012, 06:23:52 PM

I have some nice heads already set aside. I have a valve guide on its way out, that is why I am getting heads. I was gonna put the AFRs on the S/O shortblock, but I wasn't sure if that was too much volume to spool the 76 because of what the local guys at the track were trying to tell me. The car accelerates hardest in 3rd and 4th gear at the races it wasn't even spooled when I crossed the finish line. I just thought instead of re doing the valve guides in these junky heads, I would buy a new set of pro comps, for $600 you can't go wrong, up here in my area junk yards are charging $750 for GT40 heads if you can even find em, that is criminal if you ask me. I have a bunch of other cars, so I can use the heads on another project. I might even just do a quick rebuild in the winter with just rods and dish pistons, and slap the T67 back on it when I get it back I don't it is all up in the air still.

Will upgrading heads increase or decrease turbo spool times?

Reply #9 – August 30, 2012, 12:17:38 AM

Well, if the Pro-Comp heads turn out to be junk (and boy, there are some horrific stories out there on those!) you'll only lose the S/O engine.

Will upgrading heads increase or decrease turbo spool times?

Reply #10 – August 30, 2012, 06:36:28 PM

Sounds like that engine at least needs some timing thrown at it down low to get that turbo to do something. What are you tuning it with?