E85 and 92 Octane with Big Bore Stock Intake and FRPP

[BruceH]

Went to the dyno today. Results were a little disappointing but I think they revealed some limitations with parts.

Gains were about 10rwhp and 2tq. I'm showing uncorrected but the corrected numbers and differences were very similar.

Blue lines are today with E85, red are the same setup with 92 octane and green are from the same motor with a C&L Racer cai, FRPP intake with 62mm FRPP tb, and Mac LT headers with high flow cats.

I'm fairly certain that the motor is constricted from some or all of the stock parts I'm using. The Bullitt cai is the first suspect, the 322 cubic inch motor may have hit the limit of airflow for it. Next suspect is the stock 55mm tb. It flows 875cfm but if I understand airflow requirements correctly it could be choking the motor after about 5k rpm.

Next up is the stock intake manifold. I read an article once that said each runner was capable of 232 cfm which would put the total airflow capability at 938 cfm. Once again this is if I understand what I read correctly and if my memory is working right.

The last part that's different are the headers. Right now it has JBA short headers on with stock cats. When it made 438rhwp it had Mac LT headers. I know that they make a big difference with stock motors and wouldn't be surprised if this was the cause of most of the higher rpm losses. The only thing that makes me second guess it that I've made a whole lot more power with the stock exhaust components and forced induction. Of course forced induction forces it's way through the constricted parts so they don't matter as much when running it.

I'm not planning on changing anything. I like the car just fine as is. I do know that there are over 40rwhp available by changing a few parts but the extra ponies are only there in the higher rpms and airflows. Up to 5k all of the setups are fairly close.

The purpose of posting this is for anyone who might be researching n/a combos. These were my results, yours might be different.

 

[JeremyH]

A good rule of thumb for intake parts is the cfm flow should be roughly 2.1-2.2 times the flywheel horsepower.

Granted this is from a racing engineer for boosted setups. Not sure how it applies to n/a.

 

[MGT2009]

Thats a lot of power loss just from CAI, TB and headers.

 

[702GT]

I'm surprised you're not showing better torque yield on E85. That was the biggest area of improvement for me. The tuner was able to cram a bunch of spark in the bottom end under the safety of ethanol. Maybe the FI just feeds the corn huffer better. I think I saw P1SC for sale somewhere... you could make some nasty torque with that P1 on E85 with the stock manifold Bruce. Oh but you know that...

But really, those are great numbers.. naturally..
Oooh nooo... my porn slipped out...

https://www.youtube.com/watch?v=QsT3TzI94Ok

 

[Department Of Boost]

NA Intake tracts are tough for mortals to "math out". One factor that is huge in a NA intake is pulse timing. Every time the intake valve closes there is a pulse wave that runs back up the intake. If you change plenum size, runner length, runner size, etc. Things can either go good or bad. If the pulses time out correctly they will cause more cylinder filling. If the pulse timing gets worse it will decrease cylinder filling.

 

[BruceH]

A good rule of thumb for intake parts is the cfm flow should be roughly 2.1-2.2 times the flywheel horsepower.

Granted this is from a racing engineer for boosted setups. Not sure how it applies to n/a.

That formula would be pretty close to what I'm seeing, around 450-465 at the flywheel with a 15% driveline loss.

Thats a lot of power loss just from CAI, TB and headers.

The motor can digest more air and fuel but it just can't get any more with the 55mm tb and Bullitt cai. That is if the cfm guesstimates are correct.

I'm surprised you're not showing better torque yield on E85. That was the biggest area of improvement for me. The tuner was able to cram a bunch of spark in the bottom end under the safety of ethanol. Maybe the FI just feeds the corn huffer better. I think I saw P1SC for sale somewhere... you could make some nasty torque with that P1 on E85 with the stock manifold Bruce. Oh but you know that...

But really, those are great numbers.. naturally..
Oooh nooo... my porn slipped out...


https://www.youtube.com/watch?v=QsT3TzI94Ok

Another reason I think it's choking on limited airflow. The differences should of been greater but the motor can only get so much air. I really think that the extra 41 cubic inches and cnc heads are more than the Bullitt cai and stock tb can support past 5k rpm.

NA Intake tracts are tough for mortals to "math out". One factor that is huge in a NA intake is pulse timing. Every time the intake valve closes there is a pulse wave that runs back up the intake. If you change plenum size, runner length, runner size, etc. Things can either go good or bad. If the pulses time out correctly they will cause more cylinder filling. If the pulse timing gets worse it will decrease cylinder filling.

That's interesting. It's somewhat odd how the different fuels and setups are almost identical to 5k. The current setup gained with e85 only after 5k. I think that's because it needs a little less air.

FWIW the 32lb fuel injectors are keeping it fueled up to about 6500rpm. Delta pressure is commanded to a high of 58psi. Fuel pump is the stock unit with an 8 gauge power wire. It was maxed out 100% duty cycle at 5100 rpm which is just a little past where rail psi was commanded to go from 54 to 58 psi. The a/f ratio didn't start to get lean until 6600 rpm and even then it was still at an acceptable range but the pull was terminated. We (me and the dyno operator) were looking for it to run out of pump so it didn't catch us by surprise. It really helps to have someone watching what you are also watching. The minute I saw the a/f go above 13.1 I let up and he was doing the "cut it" hand motion at the exact same time.

Most of my use is under 5k, I haven't been to the track in 3 years and even then I was just a test and tune guy. As much as I'd like to squeeze every last bit out of it n/a it doesn't make any sense. Even if I went to the track as is it would/should turn in a respectable n/a 3v time.

For now I'm going to run the e85 out, switch it back to 92 octane and just enjoy the car. There is a new P1SC kit available for $4k that I know of and I'm sure it would be able to push this setup into the 700rhwp range but I've already been there and it's just too much for what I do.

The car is a pleasure to drive right now, I'm going to keep it that way.

 

[BruceH]

One other thing I just noticed on the data log is that calculated load maxed out at 5100 rpm. Load is calculated based on some of the tune data so it's only as good as the tune. However, it's still going to show a good indication of how well the motor is digesting air.

At 5100 rpm the load is 1.004 but at 6000 rpm it's down to .917 and 6500 rpm brings it down to .855. I'm thinking that's just another indication of an airflow shortage. Load at 1.0 means that the motor is digesting 100% of the air it can for it's displacement and rpm.

 

[702GT]

One other thing I just noticed on the data log is that calculated load maxed out at 5100 rpm. Load is calculated based on some of the tune data so it's only as good as the tune. However, it's still going to show a good indication of how well the motor is digesting air.

At 5100 rpm the load is 1.004 but at 6000 rpm it's down to .917 and 6500 rpm brings it down to .855. I'm thinking that's just another indication of an airflow shortage. Load at 1.0 means that the motor is digesting 100% of the air it can for it's displacement and rpm.

I couldn't even compare my datalogs to yours when I ran the FRPP manifold and GT500 TB. It was too much for a NA 281 to use and cost me more power in the bottom range than I made up for in the top. I wasn't running a max power cam either. The car made 365whp@6700rpm and a shallow 320wtq@4800rpm. The car felt great above 5,000rpm, obviously. But I found no fun to be had on the street with this setup. It was either NASCAR or Go-Kart. There was no happy medium. The car wasn't slow with this setup by any means, it was just all top-end. I miss the shit out of the Thumpr cams. I haven't seen anyone hump my car in years since I went FI, and car alarms don't respond to blower whistle either. I no long strike terror in Prius drivers at red lights, but for some reason all the turbo diesel trucks want to roll on me. I still make better torque:weight ratio than they do so it's all good lol.

I still think you'd enjoy that P1 with an electronic boost controlled wastegate. It doesn't have to be a 700whp monster, it just *can* be.

 

[Nutter281]

Sorry if I missed it - Bruce did you state what cams your running? Or did you keep those stock to maintain streetability?

Austin

 

[Boone]

Thanks for the baseline, Bruce.

I'm running your setup with a C&L Racer intake and C&L manifold. I'll have JBA LT's with a catted H-pipe and Rousch Extreme Performance exhaust. Cams and heads are Livernois Stage 3. My airflow restrictions will be the stock TB and the 1 5/8" primaries, I would think. I'm hoping that these will save my low end torque numbers to drive off corners where second gear is a waste of time.

Btw, I love the way you're not uber-hungry for 700+hp. It eases my urge to slap on FI and blast out 800hp of unusable fury. I'll be happy with anything close to 420whp. Of course 450whp would be better to keep up with the GT350.

 

[BruceH]

Sorry if I missed it - Bruce did you state what cams your running? Or did you keep those stock to maintain streetability?

Austin

They are a custom grind more suited for forced induction. The durations and lifts are exactly the same as comp 127500. The differences are that the lsa is 113 and the icl is 108. 127500 have a 102 icl and 112 lsa.

Sometimes I think real hard about a set of Hot Rod or Lunati 21270716 cams. They have a tighter lsa, lower lift, (easier on the springs and I don't think I'd lose much with a lower lift) and different icl. IIRC Hot Rods have a crazy installed icl of 92 which helps with the low end. Since they don't require limiters it's just a matter of adjusting the tune for more retard in the higher rpms to change the effective icl for more top end power. I really think that Hot Rods had a whole lot of thought put into them and that they require a little thought from the tuner to get the most power out of them.

The Lunati cams have the specs I'd like to try. More duration, 112 lsa and 102 icl. A set of 10 degree limiters would allow for some retard at higher rpms. The big choice with Lunati would be going with 21270716 or 18. There's a point where it's too much cam. I don't know what that point is. I do know that since my motor is stroked it could take advantage of more intake duration. At least that's what I think at this point in time. One of the things I really like about modding the car is that I get to think about and learn things I never knew before.

Thanks for the baseline, Bruce.

I'm running your setup with a C&L Racer intake and C&L manifold. I'll have JBA LT's with a catted H-pipe and Rousch Extreme Performance exhaust. Cams and heads are Livernois Stage 3. My airflow restrictions will be the stock TB and the 1 5/8" primaries, I would think. I'm hoping that these will save my low end torque numbers to drive off corners where second gear is a waste of time.

Btw, I love the way you're not uber-hungry for 700+hp. It eases my urge to slap on FI and blast out 800hp of unusable fury. I'll be happy with anything close to 420whp. Of course 450whp would be better to keep up with the GT350.

I'm wondering how much of a restriction the stock tb is? The internet is filled with conflicting data about cfm and power. Some say 2.2 cfm per hp and some say 1.4 - 1.6. I think the 2.2 is for head flow while the lower numbers are for the tb and cai but I'm not really sure. It could be possible that the exhaust is what's holding me back. I know that long tubes make a huge difference with the stock motor and Hot Rod cams. If they make that much difference with 281 cubic inches then they would probably make a big difference with 322.

I've tried high flow cats with a .030 over 4.6 and they didn't do anything. Maybe they would now with more displacement?

Part of me wants to experiment with different setups but most of me is very happy with how things are right now. We get jaded reading about all the big power setups and forget that not too long ago a 300hp motor was considered pretty stout. If I'm making 387rhwp on pump gas that's about 450 at the flywheel. That's pretty respectable in my book.

I already know what to add for 438rhwp. Mac Lt, high flow cats, 62mm tb, and FRPP intake.

Maybe longer duration cams would let more air in and out. Maybe my restriction is somewhere else. I'm tempted to install a 60mm GT500 tb. I already have one that's modified to use the stock bolt pattern. I also have an extra stock intake manifold I can modify to use the GT500 tb without an adapter. It would be an easy swap and I could log airflow to see if more air is coming in.

I don't think you will have much of a problem hitting 420.

 

[Department Of Boost]

I'm wondering how much of a restriction the stock tb is? The internet is filled with conflicting data about cfm and power. Some say 2.2 cfm per hp and some say 1.4 - 1.6. I think the 2.2 is for head flow while the lower numbers are for the tb and cai but I'm not really sure. It could be possible that the exhaust is what's holding me back. I know that long tubes make a huge difference with the stock motor and Hot Rod cams. If they make that much difference with 281 cubic inches then they would probably make a big difference with 322.

Have you seen this? Mind blown!!!!

 

[bujeezus]

Bruce, I hope after I've had my car a while, I still have your mindset of "the car is fun to drive". The last time I drove a V8 was when I owned a '90 GT back in '92. Loved that car. In '95, I went back to a 4 banger for my long work commute and until last August have been driving 4 cylinder vehicles. The Bullitt takes me back to the days of the GT. I just love this car. So much fun to drive. It always puts a smile on my face and that's what it's all about.

 

[Boone]

I do know that since my motor is stroked it could take advantage of more intake duration. At least that's what I think at this point in time.

I hate questioning people that know more than me, but why ask anyone else... so...

Why would intake duration help with the stroked cylinder? The speed of the piston is faster, but a high performance cam will be closing the intake valves after BDC, and early opening on the exhaust stroke isn't such a hot idea. I'm guessing that you're thinking the increased piston speed / vacuum and resulting flow rate can use the momentum of the incoming air to squeeze a touch more air into the cylinder volume by holding off the closing of the intake valve. Eh?

How much latitude is there for a cam manufacturer to effectively increase intake duration? And which end of the event do you feel would result in the most gains?

All this theory gets even more blurry when you add RPM and VCT variables. My head just exploded...

 

[BruceH]

I hate questioning people that know more than me, but why ask anyone else... so...

Why would intake duration help with the stroked cylinder? The speed of the piston is faster, but a high performance cam will be closing the intake valves after BDC, and early opening on the exhaust stroke isn't such a hot idea. I'm guessing that you're thinking the increased piston speed / vacuum and resulting flow rate can use the momentum of the incoming air to squeeze a touch more air into the cylinder volume by holding off the closing of the intake valve. Eh?

How much latitude is there for a cam manufacturer to effectively increase intake duration? And which end of the event do you feel would result in the most gains?

All this theory gets even more blurry when you add RPM and VCT variables. My head just exploded...

More stroke should benefit from more duration to a point. The way I'm thinking of it is that there is more cylinder area to fill with air vs a stock stroke so if the intake valve is open longer during that longer stroke more air will be in the cylinder. More air means more oxygen which means more fuel and more power.

I don't claim to be an expert in the subject, most of what I know is from trial and error. I do like sharing what I've learned, good and bad.

I don't know where the limit would be. I know a few things that work with a 3v but in no way do I claim to know what would work best. If I did I would of went with the exact combo that would produce the most power all around with the best driveability the first time.

Based on what I've seen with my setup I'm inclined to think that a 110 to 112 lsa would be best suited for my setup. I also think that a .050" intake duration of around 235 to 240 is what I'd like to try. I'd also like to keep the lift down to around .500". The reason for this is because my heads don't flow much more past .500 according to the sales literature. I haven't had them flowed. Keeping the lift down keeps the springs healthy and allows vct to work.

I really think that the Lunati cams would be ideal. I'd install them with 10 degree limiters so they could be retarded past 3k or so. One nice thing about having an active vct is that I can command different amounts of retard and see where it's affecting airflow the most.

My current cams are locked out at 108 icl. I wonder what they would do with a more standard icl of 102 for the low end? It should allow for more power in the lower rpms but should also start to choke the motor in the higher rpms. If they were installed with a 102 icl and active vct I think I'd see more airflow down low and more at the top.

It's all just a guess though. It's fun trying it out and learning but it also costs money and I've spent far too much on this car since I bought it in 2008.

Like I said earlier I already know how to make 438rhwp na with this motor and it doesn't take much on my part. The most difficult aspect would be putting long tubes back on. Long tubes, frpp intake, frpp tb, bigger cai, high flow cats and a pro chamber would set me back about $2000. It's just not worth it. Especially when I'm making almost the same amount of power up to 5k rpm right now. It's a very good street setup for my purposes and I don't have to wind it out to make peak power.

I can tell you that forced induction gets around all of the complicated stuff involving airflow because it force feeds the motor past the restrictions. It's really the easiest way to go.

Have you seen this? Mind blown!!!!

Where do you find this stuff? I'm not sure if I want to click on the link or not. From here it looks like brain damage would ensue. Lol.

 

[Department Of Boost]

Where do you find this stuff? I'm not sure if I want to click on the link or not. From here it looks like brain damage would ensue. Lol.

You really want to watch that!!!!

It wrecked everything I thought about header "flow".

 

[pacettr]

You really want to watch that!!!!

It wrecked everything I thought about header "flow".

x eleventy-billion

 

[Department Of Boost]

x eleventy-billion