Hey, I have a buddy with an 88 Formula 350... Interesting in getting some more power out of it.

Wanted me to come on here and get people's in put about what he should do-- He's thinkin ether swap out the headers or just do some intake stuff. So what do you guys think?? What would get better power cheaper?

 

I did the intake side of my stock L98.
No reduction of elapsed time.

 

IMO put the headers on. This is gonna free up some power he can feal. Those manifolds just suck, especially on a 350. Then have him port the plenum. Its a free mod that frees up some hp and its part of the intake. This way he gets a little bit of both worlds. The headers are cheaper to. Later Barrett

 

Headers and free mods.

nick

 

I have to disagree here. I did the intake, plenum and runners on my stock L98 and found nice gains, running a best of 13.81 thru stock exhaust manifolds. I also did my 92Z28convt with 305TPI and ran a best of 14.21@96mph thru the stock manifolds. The stock L98 manifolds are reported to flow pretty well.
The optimum would be to do both, since one benefits the other. The intake can be done for the cost of a new gasket set and some dremel bits.

 

Rob P,

When you did the intake side with the stock exhaust manifolds, did you have any improvement in 60' or 8th mile times? (Only have 8th mile track here). Did you change anything else at the same time (ignition, fuel pressure, etc.)? I am trying to do the best with what I've got before putting on the headers...with no improvements so far.

 

If you're talking about a near stock combo, here's what i'd recomend.

Spend your money on exhaust. SLP headers and a nice catback.

Spend your time on the intake. You'll need a decent die grinder to work the base over, but the stock TPI base is a horribly designed piece for performace. Fix the transitions in the base and smooth it all over. Port match the runnes to the plenum / base. Port the plenum up real good.

Then you have the best of both worlds. I guarantee you that the above combo will always outrun a car w/ aftermarket base / runners and stock exhaust.

 

You know, it's been several years since I did the porting on both motors. I'm pretty sure I had no base times before doing the porting. However I did notice SOTP gains after cleaning eveything up. And I don't know too many basically stock 305 TPI's (coolant bypass, hollow cat and aluminum driveshaft) that have run a best of 14.21 and 14.5 all the time.
Sorry

 

Wel the question is slightly vague....I still say Headders but what do you mean do intake stuff....I mean I would do as ssaid above headders and then free mods to the intake...On an 88 you can gut the MAf port match the Intake Port out the plenum...you can even try the siamesed base idea as It appears that idea works...

But basically If you were asking what will yeild more HP Headders or say a 52MM Tb Id have to go with headders all other things being stock....Problem is that to get an intake matched up For big gains costs way more than exhaust.....As in You get a TB the Plenum is your restriction....Do the plenum the runners are the restriction, runners, Base restriction, Base then the heads are the restriction...In the end you would spend 2 Grand and the setup would suck because you have stock manifolds....

The thing is doing the free intake stuff and then the exhaust mods would give you a more well rounded setup...


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ICON MOTORSPORTS OF CINCINNATI