[Orr89rocz]

My general concensus is probably nothing to get excited about but wanted another opinion.

Motor is a .060" over 350 (360 cubes) sbc. Compression is somewhere in the mid high 9's to 1. basically a new piston stock bottom end 80's L98 350
AFR 190 heads, 2.02 valve for about 260cfm.
280xfi hydraulic roller. 230/236 .576/.570 lift 113 lsa.
Holley stealth ram EFI intake
longtube headers, y-pipe, cutout at y

Its a 700r4 trans with 3600 stall. 3.90 gear with 28" tire.

Runs 93 octane, about 36 deg timing right now.

Its run a best of 12.2's at 111.x so far on 1.70 60's with a best 1/8 mile of 7.71 at 88mph on a 1.60 60 ft. Still needs alittle more tuning and will be dyno tuned this weekend.

We want to see 11.99 out of this setup and I think tune will help and if the launch gets back down to 1.60 or so like its capable of doing, then it may go 11.99.

My buddy wants to add 106-110 oct race gas...aviation fuel I think. Will leaning this out on race gas plus abit more timing help pick up anything? Motor wont take any more timing, knock sensor is picking up counts. From some searches here, the concensus was no but I've seen E85 guys out power 93 oct guys on same/similar setups. 10-15whp more.

So with timing changes and aggressive air fuel ratio, will we see any power?

 

[superstocker72]

with that compression probably not, the higher octane just slows the burn rate.

i wonder why you cant run 38* timing with that comp. on 93 octane without pinging...
im running 37-38* in mine with around 10.5:1 on 93??

 

[35845]

running more octane then you need is a waste of money...


you will run slower...

 

[BillsCamino]

you will run slower...

Yeah, I've seen this first handed. Too high octane actually hurts engine performance.

 

[Orr89rocz]

Thanks that is what i was thinking but wasnt sure.

i wonder why you cant run 38* timing with that comp. on 93 octane without pinging...
im running 37-38* in mine with around 10.5:1 on 93??

All setups are different but I think it may take 38, I just havent logged it at 38 yet. I thought I seen a deg or 2 pulled in the last logs i have but at 38 deg I believe he said it sounded like it pinged. I wasnt in the car on those runs. It runs good at 36, we shall try that this weekend. It may just be an overly sensitive knock sensor so I can try desensitizing it but I'd rather be safe than sorry. My old 383 only needed 34 deg to run best times

 

[Eric68]

From some searches here, the concensus was no but I've seen E85 guys out power 93 oct guys on same/similar setups. 10-15whp more.

So with timing changes and aggressive air fuel ratio, will we see any power?

What you are posting is pretty typical. Even with lower compression guys are seeing small increases on E85. It isn't because of the higher octane it is because of the alcohol and the cooling affect it has on the intake air and the extra volume it takes up in the combustion chambers.

 

[Winston Wolf]

You could try mixing in a couple gallons of 100 oct and see what it does. We have it at the pump here in a few stations, 6 bucks a gallon.

 

[rustbucket79]

Buy a 5 gallon pail of VP 113, jet accordingly.
A better, more permanent improvement would be something like a 4.30 rear gear, 28's are tall for a 3.90 gear. I would hazzard that a 4.56 would be better still assuming your engine has the trap rpm capability.

 

[Calculated Risk]

If it allows you to run a few more degrees of timing and prevents the detonation/pre-ignition that your seeing then yes you'll make more power.

You mention Av gas, if thats the case see if that 106 is motor or research octane.

 

[Orr89rocz]

28's are tall for a 3.90 gear.

Yep, he is suppose to buy a set of 26" tires but found a deal on a light used set of 28" drag radials. Worked well enough so far, its hooking but just not coming out as hot as it should be IMO.

it doesnt have much rpm capability. Stock bottom end we dont want to go over 6200 rpm too much. Cam/intake are good for abit more than that, but the valvesprings are weak and I think its gonna float the valves any higher than 6200 if its not already doing it. We will look for that on the dyno this weekend. XFI cam with sbc 11/32" valves, i'd like to see atleast 140lbs on the seat and close to 400 open but its got old 120lb springs/360 open.

Also think the converter is hurting him. He says he's near redline at the stripe, and with near 112 mph on 28" tires, that implies a LOT of slip. I think smaller tire will help a good deal.

 

[ShouldntBeHere]

Pretty decent running combo as it is for a mild 350 with a mild cam and fuel injection..... I'm sure its got more in it with some playing to squeak 11.90s but I'm just saying it runs damn good for a mild 350....:yes:


OH and stick with 93 octane....anything higher will kill it...UNLESS you go to oxygenated VP113 or Q16.....both would be too much octane for that motor but the oxygenated part of it will help build some power. Its $$$ though and kind of "artificial" power....You wont have it all the time but for a 11 sec slip, its worth a try....Need to run it almost straight though to get the gains and you will have to add some fuel for it more then likely... (On my turbo bike I trim up the map 2% across the board for Q16.)

 

[crazydavey]

I agree with Alan but a better fuel if you want to try it would be VP MS109, which is also oxygenated and has a motor octane of 101 and a research octane of 109. The specific gravity is .722 which is close to the Q16 and 113. I'm trying it in altitude situations as my base tracks Fontana and Vegas are usually in the 2500' to 5500' range during the season. It is expensive however.....Dave

 

[Orr89rocz]

Yeah the race gas idea was just trying to use a local airports fuel that had higher octane but if it doesnt help then oh well I dont think we are going to go find oxygenated fuels

It runs ok for what it has done. Heads are ok heads, not like the newer AFR models or the other 195cc heads out there. If it had better valvesprings i think it would pick up atleast a tenth with more useable rpm, and if it had the newer castings it would pick up a few more tenths. There are other guys with similar setups running 11's or making more dyno hp than this setup with the better heads out there. Right now its running about where I thought it would run. I'd like to see it hit 113-114 mph traps tho.

 

[427L88]

As was said, best power is made by using the MINIMUM octane required. If that thing pings on 93, I would assume your balancer/TDC mark is out and you're guessing at total timing.

 

[Orr89rocz]

Hard to say on balancer, but I think its pretty close to being right. Even stock L98's will withdraw timing on 93, so I doubt the factory screwed up the balancer/timing marks. My L98 didnt want more than 35 deg timing when stock with exhaust mods. Its not really pinging but the knock sensor picks up things it doesnt like well before an audible ping

If you give it enough timing it will detonate. You cant expect it to run on 93 oct with 42 deg timing at WOT. We may head to the 1/8 mile friday to do some logs. I'll play with timing once i get air fuel sorted out.

 

[pancherj]

VERY similar to my combo. 1990 L98 (stock rotator). Old AFR's, 10:1, similar cam but on a 109LSA. Had a miniram and went 11.60/117MPH at sea level. Now it is carbed with an Air Gap (11.89/115 in 3000'DA). I think your friend has more in it. My car liked being shifted at 6800RPM (with either induction). I have 26" tires and 4.10 gears. My car absolutely HATED a cut-out at the Y-pipe. I'd lose so much coming out of the hole, that I couldn't make it up at the top end. Also, I am not familiar with the stealth ram...maybe that is holding him back some?

 

[Orr89rocz]

Not sure his race weight, but 117 mph is alot faster than I would expect this setup to go. I had a 383 with a larger cam and new AFr 195's go 119 at 2500 or so ft DA. That was a 11 to 1 comp motor. His being smaller cubed and lower compression with not as much head flow, i'd expect lower 1-teens.

I've seen 397whp as a dyno record for new AFR 195's, this cam and a stealth ram on a stock rotator. His we think is closer to 330-340whp. My 383 was 400whp. With old 190cc heads I think he is giving up a good bit of power. Even the old 195's were alittle better heads.

I am not sure his valvesprings will support 6500+ rpm where I'd probably normally shift that cam. If he had the new heads with lightweight 8mm valves and the stiff 8019 springs, then hell yeah this thing would rip. I think he shifts at 6200 right now. We will take it to 6500 on the dyno and I may ask him to try it at the track friday just to see what happens.

We will try the cutout vs exhaust. Car has been 1.60 on the cutout but at a different track on a cooler night. The other night at the 1/4 mile track it only went 1.70's and wasnt spinning.

Stealth ram is a tunnel ram type intake with a carb on it. Miniram does outflow it with much shorter runners ~3.5" vs 6.5" on the stealth ram. Its a nice intake for combination of torque and high rpm hp. Should make more torque than a miniram with alittle less RPM potential, but it will support this cam on a 350.