Cravan

I’m planning to do new runners, port the plenum, headers, exhaust, and a CAI to my l98 tpi 1989 is there anything else I should be doing to support this properly, and how much power would this generally add?

yakmastermax

Which upgraded runners? Arizona Speed Marine? Which Headers?

I would skip the intake and put the money into TPIS, Accel, or Edelbrock TPI manifold base, and or some 1.6 full roller rockers.

I have wondered what sort of power those kind of mods would make on an otherwise stock 113 haded L98 car.

Long tube headers and a cat delete, 1.6 full roller rockers, upgraded runners and manifold base... assuming the MAF adjusts well, without a tune I would think maybe 50rwhp so maybe around 265-275rwhp all said and done?

Phobos84

I know it's more work but for the money you can't beat a cam and a tune. Add that to your list and it'll feel like a whole different car. Personally I would skip the 1.6 rockers and instead go with a bigger cam. But the 1.6 rockers will add power on a stock cam for sure.

Incorvettei

Heads, cam & tune, long tube headers, and the intake work that you mentioned will be pretty stout machine

Cravan

im planning on using azspeed runners, and hedmans elite headers I plan on adding a cam later on, but wanted to start of with this and then save more for a cam and better injectors

Cravan

alright what sort of cam would you recommend and would I need to add bigger injectors for that aswell?

Cravan

Alright thank you

yakmastermax

Miles on the motor? Budget?

Cravan

130k miles and no set budget rn looking at my options and then planning on buying and adding parts when I have the money/time

vader86

Could add about 50 crank HP/TQ, especially if port matched on the intake side. Really a better base manifold is whats needed there, the base holds you back.

1.6RR would be fine right now to add along with that. A better cam would help optimize, but that needs a tune, and may need larger injectors based on what the tuner recommended.

If you were sticking with a TPI-style intake, probably something in the 210-212/220ish 050" size would be good.

Cravan

what is the base manifold? And I’ll look around my area for a good tuner and ask them for some advice

Phobos84

That all depends on you. I love big cams in streat cars but not everyone does. A cam swap can completely change the characteristics of the car. So you would need to answer that question. As far as injectors go if you go with a larger cam I would swap out injectors but you might not have to. The nice thing is if you're just running standard pump gas and not E85 you can get OEM rebuilt flex fuel injectors that will flow well over 35 lbs for very little money. I used these for a few years until I went with the Holley 76 lb injectors I have now.

Personally I like the new Summit Racing cams. They are amazing off the shelf cams and they have a lot to choose from. Also they are only around $300 so there tough to beat.

yakmastermax

With 130k miles on the current motor I wouldn't personally do the work to put a cam in it, unless I was just pulling the motor the rebuild it. The cool thing about upgrading the top end right now is later down the line all of those upgraded parts can be used with a rebuilt motor.

I would really hunt for a used Accel, TPIS Big Mouth, or Edelbrock TPI intake manifold base. That upgraded base combined with the Arizona runners, some light port matching work, some long tube headers, and some 1.6 full roller rockers should be pretty solid. 1.6 ratio rockers add lift and some duration, sorta like a cam upgrade, but without the work of going as deeply into the motor.

He'll if you want to you could upgrade heads too while you're at it for more flow, and said heads could be used later on as well.

Cravan

After some more research Im planning on doing the TPIS Miniram and Hedman elite extreme-duty 68448 headers to start off, once after that I plan on doing 1.6 RR, heads, and bigger injectors. And a tune ofc

yakmastermax

Hedman Elite 68448 are not bad, I have used several sets. If you have plans for big heads though down the road, some TPIS 1-3/4" headers would fit the exhaust ports better.

A Miniram, upgraded injectors, some 1.6 full roller rockers, long tube headers, and a good tune even on the 113 heads should be solid and get ya up around 275-290rwhp by my guess.

vader86

The base is where the heads mate to and the runners mate to the base, the bottom of the intake basically.