Timing Table

[Roadknee]

Injector constant is set to 86#. I have the rpms set back right now, before I had the 1-2 shift at 5500 and the 2-3 at 5300 but the IDC was up in the 90% range. I backed the rpms down too because it was showing 88 kpa@wot at 5500rpm. I wanted to get the 454 tb on and see if it helped, which it honestly feels about the same except the throttle is snapper now which it to be expected. So, if I lower the injector constant, do I have to change the VE tables as well? This part always seems to confuse me yet.
BLG

The VE table will not accept a number over 100. With a modified engine like yours you have to reduce the injector constant so that VE values under 100 give the engine enough fuel. If you reduce the injector constant and want fueling to remain the same, you have to reduce the VE table by the exact same percentage. Reducing your constant from 86 to 76 would be a 12 percent change. I think you'd run a little rich. Try 79. I think your engine will be happier.

Flipping the air cleaner lid increases airflow a lot. On 355chev's 1995 k1500 it increased manifold pressure from 85 kpa to 90 kpa at 5,200 rpm. The hypertech salad bowl was worth another 1 kpa.

[Fast355]

The VE table will not accept a number over 100. With a modified engine like yours you have to reduce the injector constant so that VE values under 100 give the engine enough fuel. If you reduce the injector constant and want fueling to remain the same, you have to reduce the VE table by the exact same percentage. Reducing your constant from 86 to 76 would be a 12 percent change. I think you'd run a little rich. Try 79. I think your engine will be happier.

Flipping the air cleaner lid increases airflow a lot. On 355chev's 1995 k1500 it increased manifold pressure from 85 kpa to 90 kpa at 5,200 rpm. The hypertech salad bowl was worth another 1 kpa.

If you can get one find a 454 TBI air cleaner with 5" filter lid, duct and fender opening. Its all larger and the 454 air cleaner has a built-in powerbowl from the factory.

[Fast355]

BLG's cam is pretty conservative....

In my 350 Vortec based engine I have had a
203/210 @ .050, 115* LSA
moved to a 206/210 @ .050, 110* LSA
then a 215/220 @ .050 on a 114* LSA

I recently installed a Hydroboost setup and have my eyes on a grind similar to what David Vizard spec'd for Project Sledgehammer.

This is purely a move based on prior experience with this engine and the fact I am putting a 4.56 geared GM 10.5" 14-bolt full floating rear end in the Express along with an 11" 2,800 rpm converter in the 4L80E.

I am planning on running a steel billet core 08-000-09 custom grind on a 108* LSA.

If Comp Cams will grind it that way, I am planning on Intake/Exhaust lobes of part number 3035.

276/276 @ .006
224/224 @ .050
147/147 @ .200
.353/.353 lobe lift
.565/.565 lift w 1.6 rocker
108*LSA
104* ICL

The torque curve on a carbureted 10:1 350 engine with a single plane intake manifold and crappy EQ Lightning 180cc heads was pretty decent.

RPM	TQ	HP
2,600	389	193
2,800	401	214
3,000	401	229
3,200	406	247
3,400	414	268
3,600	425	291
3,800	433	313
4,000	439	334
4,200	443	354
4,400	445	373
4,600	445	390
4,800	443	405
5,000	438	417
5,200	431	427
5,400	423	435
5,600	414	441
5,800	403	445
6,000	391	447
6,200	379	447

Given those numbers with the crappy flowing (compared to my E-Tec 170s) EQ Lightning heads my higher flowing, smaller ports should wipe the floor with that setup.

[Roadknee]

Fast - given your willingness to step up to a custom grind on a billet core, I encourage you to contact Mike Jones of Jones Cams. He is one of the top in the country and in addition to his wealth of experience he utilizes a program he developed that calculates mass flow in and out of the cylinder to optimize cam selection. With your RPM and HP/CI you're in the area where lobe shape can have a significant impact on performance, and different shapes for intake and exhaust lobes are often needed.

http://jonescams.com/

I have purchased a hydraulic roller from him and the quality is excellent. He uses a billet core with a pressed-on cast cam gear so you don't have to run a bronze distributor gear.

[brian617]

The VE table will not accept a number over 100. With a modified engine like yours you have to reduce the injector constant so that VE values under 100 give the engine enough fuel. If you reduce the injector constant and want fueling to remain the same, you have to reduce the VE table by the exact same percentage. Reducing your constant from 86 to 76 would be a 12 percent change. I think you'd run a little rich. Try 79. I think your engine will be happier.

Aren't you just robbing Peter to pay Paul?

[Fast355]

Aren't you just robbing Peter to pay Paul?

No not really.....You are basically adjusting your base pulse width (Displacement or Fuel Injector size) and fine tuning with the VE table.

[brian617]

No not really.....You are basically adjusting your base pulse width (Displacement or Fuel Injector size) and fine tuning with the VE table.

If that is true then it seems you have miss calculated your injector PPH.

[Roadknee]

If that is true then it seems you have miss calculated your injector PPH.

I don't see it that way. The engine with better heads, cam, exhaust, etc. is capable of greater than 100% VE. The VE table can not accept over 100% VE. By reducing the injector constant the ECM increases the pulse width and delivers the needed fuel. I suppose we could accomplish the same thing by setting PE AFR at a richer then desired value (say 12.0 to achive 12.5) or something like that.

[brian617]

I don't see it that way. The engine with better heads, cam, exhaust, etc. is capable of greater than 100% VE. The VE table can not accept over 100% VE. By reducing the injector constant the ECM increases the pulse width and delivers the needed fuel. I suppose we could accomplish the same thing by setting PE AFR at a richer then desired value (say 12.0 to achive 12.5) or something like that.

See now you just proved that you miss calculated you PPH. How can VE be greater than 100%? Are there any VE tables than extend beyond 100% VE OEM or aftermarket?

[BLG355]

The VE table will not accept a number over 100. With a modified engine like yours you have to reduce the injector constant so that VE values under 100 give the engine enough fuel. If you reduce the injector constant and want fueling to remain the same, you have to reduce the VE table by the exact same percentage. Reducing your constant from 86 to 76 would be a 12 percent change. I think you'd run a little rich. Try 79. I think your engine will be happier.

Flipping the air cleaner lid increases airflow a lot. On 355chev's 1995 k1500 it increased manifold pressure from 85 kpa to 90 kpa at 5,200 rpm. The hypertech salad bowl was worth another 1 kpa.

I was curious how it would run and I set it to 79 and gave it a whirl, here is the log.

BLG

[BLG355]

Finally, with the larger TB you'll want to bump of the values in the line pressure tables to compensate for the added torque your engine will make at less throttle.

I'm not certain exactly which of these values should I increase?

Attachment 8962

[Roadknee]

I was curious how it would run and I set it to 79 and gave it a whirl, here is the log.

BLG

That's better. The VE table could use some tweaking, but it's close. WOT is better, but started to lean out some in the top of second gear. Great second gear chirp BTW. How did it feel? Turn over the air cleaner lid and try it again.

[Roadknee]

I'm not certain exactly which of these values should I increase?

Attachment 8962

Its the two added line pressure vs tps tables, 0-64 and 64-128 mph. I know you need more due to the engine making more torque at lower throttle settings with the larger TB, but not sure how much.

[Roadknee]

See now you just proved that you miss calculated you PPH. How can VE be greater than 100%? Are there any VE tables than extend beyond 100% VE OEM or aftermarket?

Geez Brian, I proved no such thing. You can research if you're truly interested in learning how naturally aspirated engines can achieve greater than 100% VE. I can give you a real-world example though. I was on the engine building team in the early 1990's for the owner of a 1963 Studebaker Avanti that wanted to be the first to go 200 mph at Bonneville with a Studebaker powered Studebaker. We built a 304 v8 with a ton of headwork, big solid roller cam, tuned headers and adapted a SB mopar vic jr intake and Holley 4 bbl. That engine made 450 hp at 7,500 rpm naturally aspirated on the dyno. The carb was outfitted with one of those turbine hats that accurately measured airflow. That engine achieved 114% volumetric efficiency. Once we bolted on the Paxton supercharger it made 638 hp at 7,250 rpm. Of course the VE with the supercharger was much greater.

BTW, he achieved his goal reaching 200.426 mph in September 1993.

[brian617]

I'm missing something then. I assumed that 100% VE was each engines particular ability to move the maximum about of air volume for its given combination of parts. 100% being the most air that engine could pump regardless of the actual volume of air. If that's wrong please explain.