Got a tune up a few days ago, and hit the dyno. Finally hit the 250 mark. Temp was around 60 or so. The motor seemed to make the most power around 4750 rpms...think its time for a cam. Let me know what you think. Also is there a good heads/cam combo that will get me 300rwh? Thanks

251rwh
342rwt


89 Iroc L98
FlowMaster Cat-Back, Catco cat, EdelBrock Headers, EdelBrock Intake Manifold and Runners [Both ported], Air Foil, TB Bypass, Plenum Ported, AFPR, Gutted Air Boxs, K&N Filter, HyperTech Chip , 160 Thermo, Re-mapped Injectors, MSN Ignition, Accel Rotor, Beefed Alternator, Modded MAF, 3.42 Rear End.

 

There isn't anyway you can be making that much power with the stock heads and cam (just a little sarcasm)

LT4 Hotcam and vortec heads would do the trick without killing ur wallet

 

With exhaust and intake only, those are some good times. As mentioned before the vortec/hot cam is good and cheap. But you probably want to keep your preexisting intake and not buy another, so go with a pair of ported aluminum L98's or ported 186. If you have the money, of course go with Trick Flow or Cannfield. If you are rich and can wait a while, go with AFR's.

 

The numbers do look alittle high. I now have numbers rangeing from 242-251 lol. I guess the dynos vary alot. What do L98s come with stock 200 or so?

 

LB9 was rated at 220 with the 5spd.

I thought the L98 was supposed to be around 240

 

good running 88-92 L98 F-bodies put down right around 200hp @ the wheels stock. I got 210hp out of my 90 GTA with just new plugs, wires, and oil. Full bolt ons can add 70+ and still keep the the long or siamese runner setup. A custom tune, 1 3/4 headers, underdrive pulley's, air pump delete, and 52mm t-body could add another 30 or so.

 

I think that the L98's were rated around 230-235. But I think that they were probably only good for 200-210 at the rear wheels. This is based on the dynos that I have seen posted. This holds true for almost any car though. I have not personally seen an LT1 powered car in stock trim lay down more than 260 hp, and they are rated at 285-305 I believe. Same with Ford's Mustang Cobra's and GT's.

 

In 1987 they (l98's) made 230 at the crank. By 1992 they made right around 245 at the crank. The dyno figures vary A LOT by dyno type, exterior conditions, engine condition, but go from around 190RWHP, to 215RWHP on any given day. He's making excellent power.

Personally, I'd search out a set of used Trickflows, and a cam in the 212/222 - 216/226 area, around .480 on both sides, and 112 LSA. I doubt they will get you 300RWHP with the rest of your current mods, but I would easily bet on seeing 285'ishRWHP - and a huge swell in torque (415ft/lbs and up). You'll be fighting the LT runners and baseplate at that point. Tuning would also be a "good" idea. Yes, MAF systems WILL benefit from proper datalogging and tuning. They are flexible, but there is something to be gained by having a proper tune and letting that flexibility be used for minor adjustments - like it was meant to be.

..... ok ok, maybe 300 RWHP, I'm just saying, don't sink your hopes and dreams on it.

 

that does sound high . the mods in my sig got me a 251/318 rwhp/rwtq .Untunned and a new motor with forged pistons ( minus the turbo in the sig ..not in yet )

 

Where did you go for the dyno?

 

cammed/headed tpi's pull very awkwardly. You have all the off idle torque from the tpi usually lost in a cam, then you have your wicked midrange of tpi with the start of the cam, then you hit your topend and it just flops. But with ported tpi and a good exhaust, it pulls really well for a motor that stops at 5k. You'll love it

 

i think something was off that day. i usually go to New England dyno and make around 245ish.