Ok, here's what my '88 305 TPI had when I got it from it's last owner..

TPIS ZZ9 Camshaft
TPIS Modifed Mass Air Flow Sensor
TPIS Large Tube Intake Runners
TPIS 52MM Throttle Body
TPIS Big Mouth Manifold
TPIS Large Tube Ported Plenum
March 3 Piece Underdrive Pullies
SLP 1 5/8 Inch Headers
SLP Y-Pipe
Random Technologies High Flow Cat
SLP Cat Back

The throttle body, runners, and intake manifold have all been port matched for maximum air flow

@ 1700 RPM it's making about 177ft lbs RWT. Which is awesome but it's a bit much for a daily driver in traffic (wet weather is scary). I'd like try and get a bit more HP (currently, it peaks out @ 242 RWHP) by sacrificing a bit of that torque. What would someone recommend?

 

You've got all that on a 305? All that should have raised your rpm band quite a bit, especially on a 305. About the only thing you haven't changed is heads, and I'd say they're really holding you back. If i was you though I'd take all that good, expensive stuff and put it on a 350 or 383, it's wasted on a 305. Those parts are built for a larger engine than your running.
But 177 rwt isn't really all that much. If I was you i'd do some suspension mods first,control arms + torque arm and such, and maybe a better set of tires.

 

You mean 277ft/lbs, right?

 

Get some lower control arms with relocation brackets and some cinder blocks for the rear hatch well. You'll be amazed at the handling achieveable when there is actually weight in the back. Other than that start porting the intake if you want to kill some torque, I don't see why you would want to though.

 

No he means 177 thats at only 1700 RPMs . Damn that great Marcus, I though I might be able to beat your third gen sence I cannt beat the Vette. Hope to see you at the track this year.
Rob(Firstin87)

 

Thanks for the replies guys.

Yeah, I hear you about the 350 , but I kinda want to stay with the 305 for now.

But I think you're right about the stock heads being what's holding me back and I'm mighty tempted to go with some World Products S/Rs. Course, these would be totally unusable on a 350 (assuming I later went that route).

As for the torque, well I may just have to get used to it . In all truth, I've driven the car very little and mostly only in the wet. Part of it is just getting used to the RAM clutch engagement which feels a universe away from the LS1 clutch I'm so used to in my vette. Also, I have quite a bit of surging around low RPMs which makes the car less docile. I think it has to do with the descreened MAF or something. Something needs to be recalibrated I think.

Here's a link to the dyno graph from the last owner:



Anyone have an idea what effect the SRs might have on the graph?

Hey Rob - whatsup!! I am gonna try and get the ROC down to Union Grove sometime soon... just to get some times as I have no idea what she runs. The last owner made one run in the 14s. As for the vette... well, I need to learn to launch properly . My best is a 13.4 at GLD (after I fried my clutch)... pretty poor, but I just need to get my 60' down... it's killing me and I'll be in the 12s. . Maybe next year if the car is done by then, I will run the IROC at the y-bod vs f-bod shootout. See ya around!

 

Well according to that graph you have more like 250 ft/lbs at low rpm, that's a lot better than the 177 you were saying. And that's at the wheels right? Those are pretty damn good numbers for a 305. Hell the stock 350's only put out 230 hp at the flywheel. I'd still say do the suspension mods first, it'll definitly help with the wheel spin and acceleration, and be worth it no matter what you do to the engine.

 

Reaction time has nothing to do with ET. You could sit at the green light for 10 seconds and then go...your ET would still be the same since the timer doesnt start until you break the starting line beams.

RT (reaction time) will win or lose you a race against another driver.

 

Doh.. I meant 60' time. LOL. I'm not very exp. at drag. racing and it's been a while .

rhuarc30 - thx. for spotting that.. Haha was reading wrong side of the graph .

 

Get some South Side Machine SFC welded in and some lowe control arms too. That will stop flex and give you much better traction.

Don't do anything to reduce torque, improve traction. In fact I suggest a set of Trick Flows to realy let it breath.

What wheels, tires and gears do you have? The tires can make all the difference.

 

TrickFlows? Those will fit a 305?? I thought the iron World S/Rs were the only viable option. But hey, that's cool if they do and I'll look into finding a set (they're aluminium right?).

I already have KB SFCs (again, they were on there when I got the car). You all have convinced me that a decent set of lower ctrl arms is in order . And the tires I have now are just some stockish looking affairs. Wheels are stock IROC rims. I'm gonna go with some DRs once I get a decent 12 bot in there. Gear is the stock ratio that came on the 88 IROC with a t5... not sure what that is though.

Cheers!

 

I read an article in an old CHP or HotRod where TFs were tested on a 305 and worked well though there was some shrouding of the larger valves.

BTW, that's awsome from an LB9; congrats on a fine ride.

 

Marcus your stock rear will handle the DR just fine! Just get them you will feel a huge diff. in the take off. .2 lower 60' you wouldnt belive how much hard that feels.

 

Heh thanx... but I can't take the credit - that goes to the last owner, Orian Iglesias... he's got a MkIII Supra now. But he's gonna wish he never sold the car once I get done with building it further .