Well I went and dyno today......I guess its alright for what I did. I really dont know how to read dyno sheets. I did 4 runs 1 and 2 were the same...FP set at 48...#3 set FP to 46 and #4 set FP to 44..thats where I got my best pull...Also I think there may have been some left on the table cause after we got done I noticed the dyno fan was on low and not blowing out full blast and full blast compared to low was alot...but ohwell.

One of the guys there said not to get stuck on the peak power but the whole range. He said it was a great line.

So all you dyno gurrus tell me what you think...is it good? Tell me what to look at.

Its still a 305 but thats all I got to work with for now.

I dyno'ed 3 years ago and picked up 40 on both HP and TQ.

 

Dumb question...

Are those rear wheel or crankshaft numbers?

 

rear wheel

 

That's a printout from DynoJet chassis dyno software.

Not bad #s for a TPI; almost up into carb motor territory. Should be a whole lot more fun to drive than it was!! It should run well ahead of stock L98s. I'd expect it to do around 14.3-14.5 at the strip, maybe a bit better with really good hookup, maybe 96-97 mph.

Nothing really stands out as particularly odd about it; the torque curve looks pretty much like the usual shape of what TPI produces, no weird spikes or dips or anything. Some really useful data would have been to get them to add fuel mixture to the graph. Without that, it's not much of a tuning aid, it's only a proof for how the motor was built. You can't tell what you need to do next in the chip to maximize it. Next time, make a point of getting the wideband O2 data.

I doubt the fan afffected it too much, as long as the temp gauge was not into the red.

 

thats exactly what one of the TPI guys that does all thier work there. He said I would walk away from stock L98's....once I got out of hole....He said that I would probably do better in the 1/8th than in the 1/4 times...Im trying to get into the high 13's.....He said that I may get into the high 8's if I can get out without spining..

 

They didnt have a way to run the fuel graph I dont think. Once I run it with Moates software will I be able to tell what I could do to pick some up?

 

They look really solid but you can see where the stock TPI becomes a restriction. You have monster low end but the top end falls off pretty fast and is on par for most TPI set-ups. Good numbers and great torque.

I forgot to mention. Some plenum port work and shorter runners will make that cam shine in the upper rpms. You should be able to pull a LT1 cam 305 to 6k with ease without much power drop off. It now gives you a good idea what you have to do next. Next time use a wide band and see exactly where you stand.

 

When he was pullin it..I was like... .......its gonna blow......he pushed it pretty hard....


What do I have to do next? what should be next? The plenum is already ported...

 

It is sad that the stock TPI can't really support even a heads and cam 305. Have you looked into better runners or the high flow base offered by some companies. The TPI gurus will help you out and I am not as knowledgable in that part. You are in a tough posistion because all TPI replacement set-ups are a bit to big for a 305. You may want to consider an LT1 intake swap, I have always wanted to see that done to a 305. I think it would be a perfect fit. I only say this because tuned LT1 cammed 305 TBI's will make power past 5K on up to 6K. That is with a different intake and modified unit though. I am sure with better tuning and a little magic suggested by the TPI guys should take that HP curve a bit higher.

 

Looks good for a stock head TPI 305, my TBI with similar mods (exhaust) and cam made 200 rwhp and 244 rwtq. I think that makes a good comparison to what the TPI intake can do on an engine with stock heads.

I also agree with decent traction 2.1x 60' (or better) you will be in the low 14s at 96-98 mph.

 

I think those numbers look pretty good.

I can kinda see where TPI kinda quit making power, whereas a carb would keep sailing further up the chart.

But a carb wouldn't make that kinda torque down that low unless it was cammed for it.

 

Pretty good. Looks like you should be shifting around 5200 to keep you in the curve.

 

That's not bad. Here's my stock L98, for comparison, with the Flowmaster ForceII catback. I'm not sure what's up with the flatness around 3600-3800 RPM and onward.

 

Why is your TQ so much more than mine? I thought the 350 and 305 were alomost the same....and with the cam I put in was the same as 350 cam...I think something aint right...

you know how it is, always want more!

I figured with everything I added, I would have gotten alittle more out of it. How come not?

do you think ther still may be some left in the chip?

Sealed Ram Air Boxes "Fogs removed", Ported Plenum, LT1 cam, 1.6rr's, SLP Tri-Y headers coated, 160 fan switch and stat, Holley AFPR, MSD ignition mods, Underdrive Pullies 3-set.

Only 40hp?

 

There's probably a little bit to gain left in the chip. However, you need to datalog your dyno run to look for knock retard and you also need to get wide-band o2 data from your dyno run. With that information, you have all you need to tune the PROM for max performance.

No offense, but those numbers seem a little low for what you have in it.

My friend has a low mileage 1992 1-LE Z-28 with a BONE STOCK 305 TPI 5-speed. He added a MSD 6al box, MSD coil, MSD wires, K&N filters, and an SLP (dual-dual) cat-back. His car made 238 rwhp and 307 rwtq. He also run's 13.9's in the 1/4.

Get that data!! There's probably more power to be had!

 

I agree 100% with ya...Im thinking I should have more.

 

Don't forget though that same cam in a 350 will go farther than it will in a 305. Similar mods will go farther on motors larger than your 305. You have great numbers though. A cutom tune and some better runners should really wake up that top end.

 

So you only put in the L98 cam? Your numbers are a bit higher than some friends of mine with 305s, but they don't have headers, so the numbers may be on target. I know I'm running a tad rich and should be pulling a bit more. The curves do look fairly similar to my friends 305s with T-5s, just a tad higher.

Well, since I posted my dyno run, does anyone have an idea of what the flat spot on my curve is about? From 3800 to about 4200, it's flat. I also have a T-56 on my car, forgot to mention that.

 

Nothing appears to be wrong. It has a slight slope to it but not much. That is just solid power and about the limit of the stock TPI. You can see it drops off after that. FLat power is good.

 

Those 45 extra cubes in the 350 will always give a better account of themselves in the torque category than a 305. Just plain old physics, really.

Now if you ported and polished those 081 heads of yours, hmmm, that thing should drop right into the high 13s on a good run. And a set of 3.42 gears ... well, you would difinitely be in the 13s

 

Im going to the track tomorrow and run some 1/8th times...my cable came in so I can use Moates software,
would it be a good idea that I have it hooked up when I do the runs to see what it does? Will that software be able to tell me where I may be able to pick up some more HP?

 

That's about 280 flywheel hp. Your main restriction is with the stock base and runners. You'd really feel the difference with an aftermarket base and runner set-up, especially in the higher RPMs.

Robert

 

I am a little disappointed in the numbers with a LT1 cam in it. We have about the same mods to the engines. I haven't had mine dynoed since some of my mods were done but I would have thought the LT1 cam would have done better than that. I plan on putting in a compcam 212/218 114LSA and Torquer 305 heads. Even with those numbers I would expect you to run low 14's. Put a high stall torque converter in it and it will really wake it up at the track and on the street. It doen't help at the dyno but it makes it a lot more fun to drive on the street/strip.

 

See what I mean? Look at the mods you got ,,,your right we are about the same...and with out a cam you pulled 213....Im thinking the tuning is way off...gotta be!!!!!

I dont know what to do...

 

It is time to start burning your own chips. You would be amazed of how your car will run afterwards. You need to burn like 50 chips to get it right. This is something that mail order can never touch.