give me feedback on your opinions. boost, power, a/f

[SuperSonic]

hey guys. Just had my car dynoed at bisimoto as recomended by LES Wanted some opinions. Bisi said for every day driving the set up is pushing it on the edge, tracking he would not recomend. I dont track the car, but occasionally push it. It was dynoed at about 70 degrees out give or take. What are some of your guys thoughts. Bisi said he would like the A/F to be just a little lower. Does SOS do reflashes for the stock ecu. or can the FPR be adjusted to put more fuel into the car? I told him I just wanted to get safe hp for occasionally fun in the hills. So whats ur guy take

edit..... prob some more back ground. pride v1 exhaust, test pipes (slightly whats making it more lean), ct headers, ctsc whipple at 6 psi.

the test pipes make a big difference. Les said with his set up of autorotor he was at 352 whp with only difference he had cats. thus my reasoning test pipes net me 16 whp if the idea the autorotor produces 20 more hp and i was only 4 hp below autorotor (correct me if im wrong). i could prob get a few hp more with better fuel curve, or fuel hill i should say lol.

 

[NetViper]

I had always heard the test pipes didn't make that much difference.

When talking to Shad he said there might be an issue using the pride because it is not a "free flowing" exhaust. I have no idea if that would lean it out, but it is something you could try.

 

[Moses]

High flow cats and taitec lightweight might make the difference......

 

[kookoo4nsx]

I don't know how AFR's compare between SC and Turbo.
That being said a motor is a motor. Afr's over 12 are considered too high when under boost......................and your afr's are in the 13's.

 

[NetViper]

I don't know how AFR's compare between SC and Turbo.
That being said a motor is a motor. Afr's over 12 are considered too high when under boost......................and your afr's are in the 13's.

Should be the same. Somewhere around 11.4-11.8

 

[SuperSonic]

Can the fpr be adjusted to put more fuel out?

 

[NetViper]

Can the fpr be adjusted to put more fuel out?

I thought you can adjust the screw there to increase fuel pressure?

 

[SuperSonic]

Thats what i thought. My bro had one on his s2k, comptech and what not. I remember we had to switch it to a aem 1-1 i guess it was called. If i remember the comptech isnt a 1-1 but progressive fpr. When we ran his car at 6 psi i think it was ok but i remember at the time we had a/f guage and were constantly messing with the screw on top. Not a good idea as it went from wayyyyy rich to way lean and car would sputter and stuff. If i attempt to do this, which way would i turn it to increase fuel. If it can be increased just a little it cant hurt.

 

[StmpoRaceProducts]

If your using 100% of the old CT hardware... like the vortec fmu and tuning ...

an AEM or programable computer will solve your problem of a/f

Im sure Bisi would have said that..

 

[DDozier]

hey guys. Just had my car dynoed at bisimoto as recomended by LES Wanted some opinions. Bisi said for every day driving the set up is pushing it on the edge

Listen to your tuner, this car is in my opinion not save to run in boost. This is only my opinion but here is what I am looking at to form my opionion.

Looking at you pulls by:

2500 RPM you are making 3lbs of boost but your AFR is at 14.0:1
3000 RPM you are making 3.7lbs of boost your AFR is at 14.0:1
3500 RPM you are making 4.2lbs of boost your AFR is at 14.1:1
4000 RPM you are making 5.1lbs of boost your AFR is at 13.6:1
4500 RPM you are making 5.4lbs of boost your AFR is at 13.4:1

I can go on pulling numbers out of your graph but these AFR's are leaner than a stock non-boosted NSX likes to run, most stock NSX's are in the 13.0 - 13.4:1 ratio untill VTEC then they move sharply into the 12.7 - 12.9:1. You are running leaner than a NA car at almost every part or your pull except for the 6500-7500 RPM part of your pull and even then you just get to the same AFR's of a non-boosted NSX. Most would agree that on 91-93 octane fuel with 6lbs of boost you should target 11.5-11.7:1. With a whipple and 91 octain I would be inclined to move to the 11.5:1 side of the scale, as bad gas, old gas, higher than normal IAT can all lead to detonation and could ruin your engine. The Whipples run hot and easily heat soak into the 180-190 degree IAT's when driven hard for any length of time the stock ECU will add a little fuel and pull a little timing but not enough to offset the IAT's and this car will most likely have detonation issues.

I have attached two base runs from my '04 prior to the turbo system being installed, I have pulled up the size of the AFR graph to make it easy to see what I am talking about. Keep in mind these pulls are still NA and are factory stock pulls other than an aftermarket exhaust.

I would talk to your tuner and look at options to correct the fuel issues you have. Steps to take before you spend any alot more money.

1. change fuel filter
2. have injectors cleaned and ballanced
3. verify base fuel pressure of the FPR and peak fuel pressure of FPR
4. verify idle AFR is at or near 14.7:1
5. look at your fuel trims and make sure they are within spec.

Moving on after that is done
1. talk to Shad about reflashing the ASM, but on an OBDII car he will most likely recommend an AEM FIC
2. Adjust the FPR to a higher base fuel pressure, then look at your fuel trims again and make sure they have not moved to much.
3. Still having fuel issues you may need to look at a complete fuel system upgrade to deal with the demands of the Whipple, AEM FIC, Walbro pump, Larger injectors, 1:1 FPR or put the stock one back on and remove the Comptech ASM.

Others may give you other ideas and may think mine are stupid but untill you and your tuner are 100% sure the car is safe I would stay out of boost.

Sorry for the bad news, but you did ask for opinions.

Dave

 

[NetViper]

I think Dave's advice is excellent.

 

[cptnsx]

I have the SOS intercooled supercharger with Prospeed 100 cell cats and the Pride V1 exhaust. With no cats and the Cantrell exhaust I dynoed at 412rwhp. With no cats, the Pride V1 exhaust, and the B-Line air intake with a 9 inch Amsoil filter and slightly smaller pulley I was at 420rwhp. My highest boost numbers from the first dyno session to the last with the new equipment was 8.9 to 9.4. However I gained around 1 to 1.5psi in my mid-range from 3k to 7K. My new tune had to be changed in the mid range. My air fuel ratio is around 11.1 to 11.3 in that mid range going to around 11.55 up top. I have hundreds of data logs here in Vegas. When I went to the Pride V1 exhaust I noticed my boost increased to about .2psi and I also saw an increase with the B-line air intake of around .2psi (could be the margin of error associated with weather on different days.)

Cody has designed an incredible header and exhaust system for supercharged cars. The car he tested made from 474ish without to 490ish with his system. This car is making a hundred more than you and 50 to 70 more than me. It should have the potential for much greater restriction than both of us. However it only gained 7 to 8 foot pounds of torque up top. A supercharged car is not as impacted by exhaust restriction as a N/A or turbo car when it comes to flow (for them its intake restriction). That car Cody tested did make a significant increase in torque down low. This is typically not normal since larger pipes shift the powerband higher. However Cody headers have very long primary runners and they are equal length not only with respect to each bank but as a whole as well. Therefore it is only one conclusion, wave tuning accounts for the huge increase in torque down low. The slight restriction up top (the 7-8 torque gain there) accounts for the gains there. With my car and especially yours the gain up top would be probably minimal or non-existent.

With my new 100 cell cats I not only passed emissions but my air fuel ratio stayed almost identical and I noticed no significant change in boost psi (maybe an increase of .1 or .2psi – a margin of error). For me the biggest restriction is either the intercooler (this is what Chris at SOS stated before we went to the slightly smaller pulley) or a restriction in the head or intake tract after the throttle body from 6.5K on up since my psi increase with the new pulley goes from +1.5 down low to +1 in the upper midrange to only +.5 up top.

So if you like the sound of the Pride V1 keep it – the slight restriction is offset by the slight increase in boost. 100 cell cats seem to offer little to no restriction – I’m sure the higher cell counts will but probably no more than 5-10hp. The cats will change the note of the Pride V1. It will be slightly lower, with less volume, no rasp (esp. around 2K-3K) and more refined. Better in some ways (when you want to be more civil) and worse when you at very high rpms and want to be obnoxious). Also the Pride V1 has slightly larger pipe diameter compared to the V2. I hated, hated the rasp down low so I’m happy with the cats.

You’re probably making that power at 6744 because you are at the “right” air fuel ratio for max power. However that is still too lean for a non-factory force induction car (should be 11.1-11.5). You’re crazy lean everywhere else – which is killing power. I bet on the road you are much richer since the stock ecu will pull timing and add fuel as your ait increase in real world driving. One question was it a tail pipe sniffer – if so then the high lean numbers are probably false.

I heard that the new AEM EMS 2 is coming out for the NSX and will work with the ODBII and drive-by-wire cars. Check with SOS. You definitely need this. I would also get the intercooler…. It will lower your ait around 50-80 degrees and allow you to keep timing closer to factory setting (safely) and the EMS 2 can be set to aggressive pull timing as the ait increase. I pull around 3-4 degrees around 180-190 (with repeated 60-100 blasts) and it will pull almost 8 if it ever gets to 250 (never more than 200 in Vegas 110+ temps and repeated 3rd gear WOT runs). The sensor in the SOS intercooler will heatsoak more than the normal ait location but that just makes the tune more safe as it gets hot or if you decide to track the car with the supercharger. If you go this route you might as well get a smaller pulley, injectors, fuel pump, O2 wideband, etc and make the 400rwhp reliably.

 

[dynomike]

I tried to tell you it was going to be lean. There are few options that I have come up with over the years as we have been installing and tuning NSX'S with Comptech Superchargers on them for over 10 years. It all depends on if you want to remain emissions compliant or not. My guess is you don't care about emissions because you are running test pipes. One option is in my signature the others will involve taking a very close look at the stock fuel system making sure everything is at 100% and possibly adding a Ct engineering ASM.

 

[SuperSonic]

Thanks for tbe advice guys. This will sound weird and maybe it was a off day thing but i compared my graph bjsi did to a stock nsx..... Actually where mine were at 5k' they suddenly dropped fast to 12.5 after vtec. The chart bisi showed me of a stock nsx with exhaust was low at 5k, prob 12.5 then shot up to 13.5 in vtec, basically the opposite of mine.

And yes, it was a tail pipe snifer test. How much will that throw off the a/f? I will be getting the guages in about a month for boost and a/f. I cant imagine it be this off in a/f..... I spoke with shad who told me the a/f would be almost close to stock. I cant imagine the test pipes lean it out that much.

I might just get the guages sooner so i can mess with the a/f by adjusting the screw on the fpr.

Another ?, the comptech fpr is run off the vacume line for the boost. I dont know much but i assume more boost the more open it is to let fuel in. So if i open the valve more at lower boost it should let more fuel in as it seems it was fine at full boost but thats 6k later, id need the full boost effect at 3k to keep it in the good range.

For the kit being bolt on, i cant see how it would be so off. I know the auto rotor has a tuning program for fuel. If i have to get aem or something i mind as well sell it and go turbo lol. I gota see if fpr can be adjusted for more fuel, call shad, and prob sos.

Thanks guys for all your support

 

[cptnsx]

Get an O2 sensor bung welded into your test pipes. Make sure the dyno shop has good O2 sensors to use during your dyno test. Sniffing from the tailpipe can be 1 to 1.5 A/F ratio off (lean).

I don't think you are really that lean. If you were then your car should have been pinging during the test since the stock ECU will not pull timing until the ait gets really hot and heat soaked in real world driving not a simple dyno pull.

Test pipes don't lean anything out. At most your backpressure would be slighty reduced and at some points in the rpm range you could pick up a couple foot pounds of torque. This would only affect your A/F ratio (maybe) a couple of tenths not full points.

 

[cptnsx]

I thought you can adjust the screw there to increase fuel pressure?

This would screw up his stock map everywhere ... until the short term fuel trims were applied to the long terms fuel trims and then the WOT tables. And then he would be lean again.

Go to someone familiar with the Comptech setup and get the ESM/ASC or whatever they call that thing setup correctly. Then on the dyno get the fuel pressure set right. Or get the AEM FIC, bigger injectors and the stock fuel pressure regulator and tune the car on a dyno with real good O2 sensors in a test pipe -- should do both banks. While you are probably not that lean .... the Comptech typically runs very rich because it runs close to stock ignition timing when it is not heat soaked.

 

[StmpoRaceProducts]

Get an O2 sensor bung welded into your test pipes. Make sure the dyno shop has good O2 sensors to use during your dyno test. Sniffing from the tailpipe can be 1 to 1.5 A/F ratio off (lean).

I don't think you are really that lean. If you were then your car should have been pinging during the test since the stock ECU will not pull timing until the ait gets really hot and heat soaked in real world driving not a simple dyno pull.

Test pipes don't lean anything out. At most your backpressure would be slighty reduced and at some points in the rpm range you could pick up a couple foot pounds of torque. This would only affect your A/F ratio (maybe) a couple of tenths not full points.

There is good advice here... and you are knowledgable...

I'm not sure if you know this... but Bisi is one of the most rerspected tuners in the nation if not the world. I only know of 1 tuner I would rather touch my car than Bisi...

OP.... listen to Bisi... your lean... and he knows more than most about fuel mixtures... prior to yuning... Bisi was a chemist prior to tuning and building motors

Your old version ct sc has outdated components... an fic and adjustable fpr will provide bisi with what he needs to deliver your nsx with reliable hp....

If he says stay off the gas pedal.... stay off the gas pedal

good luck

 

[SuperSonic]

Why read a book when there is so much more knowledge here. Thanks guys. Now my question is then if your correct in test pipes should only slightly lean it by .2 or so, that would mean the ctsc has alwaus been built to run lean. That sounds wrong. If in fact the tail pipe is off 1-1.5 i would be fine. My 5k at 12.5 and vtec engage at 11.5. I will just install the a/f sooner than i expected.

And adjusting the screw on the fpr clockwise to increade it wouldnt put more fuel throughout the curve?

100 percent sure i need to get a real af number to be sure from my test pipe. Again, thanks fi experts.

 

[NetViper]

Why read a book when there is so much more knowledge here. Thanks guys. Now my question is then if your correct in test pipes should only slightly lean it by .2 or so, that would mean the ctsc has alwaus been built to run lean. That sounds wrong. If in fact the tail pipe is off 1-1.5 i would be fine. My 5k at 12.5 and vtec engage at 11.5. I will just install the a/f sooner than i expected.

And adjusting the screw on the fpr clockwise to increade it wouldnt put more fuel throughout the curve?

100 percent sure i need to get a real af number to be sure from my test pipe. Again, thanks fi experts.

How long have you had the ctsc on the car? It does seem strange for it to be lean if it has been on there a long time.

 

[SuperSonic]

How long have you had the ctsc on the car? It does seem strange for it to be lean if it has been on there a long time.

Actually the original owner frrom new york had it installed. The install looks good, shad said he vaguely remembers the car as being good. Its been on the car since 05 id say.

 

[NetViper]

Actually the original owner frrom new york had it installed. The install looks good, shad said he vaguely remembers the car as being good. Its been on the car since 05 id say.

I would follow daves advice and check all the parts that could make it go lean.

 

[SuperSonic]

Is it even a possibility the frp could be slightly adjusted since the car was in new york and now cali. Would there be diff pressure that would affect it. Like i said i gona check those mentioned above but if the kit is a bolt on kit and test pipes do more to back pressure than A/F, the af in the tail pipe was off or possible the fpr can be adjusted. Otherwise i dont think it shod be that high. I need an A/F guage lol.

 

[DDozier]

Is it even a possibility the frp could be slightly adjusted since the car was in new york and now cali. Would there be diff pressure that would affect it. Like i said i gona check those mentioned above but if the kit is a bolt on kit and test pipes do more to back pressure than A/F, the af in the tail pipe was off or possible the fpr can be adjusted. Otherwise i dont think it shod be that high. I need an A/F guage lol.

I am not your tuner, but I would not recommend you make any changes to the FPR but you can find out what is going on with a simple OBDII scanner. If you do not own a OBDII scan tool go to autozone plug in a scan tool and look at your fuel trims during idle, if they are (+) numbers then you can add more base fuel pressure with the FPR, if they are (-) numbers then you are already running to much base fuel pressure and any changes will mess everything up. This car needs to be checked and varified with a known good wideband in a controlled environment. Unless you have an exhaust leak your tail pipe test on the dyno should not be 1-1.5 points off, remember these tail pipe readings were without cats correct. Even then if the cats were in place at idle the readings may be scewed a little but at WOT the volume of gas moving through the cat will reduce the efficiency of the cat and will end up giving readings much closer to the actual AFR at the header or test pipe. Having said that I think it is a great idea to monitor AFR all the time and installing a good wideband that can log data not just show you a number or flash some lights is a great tool for measuring the health of your cars fuel system. Logging AFR with a reference to RPM and Boost would be the best option. If you had this data you could pull the data anytime you wanted and send it to your tuner and let him review the logs and decide if a retune is needed or not without the data you really just have dancing lights on your dash. Better than nothing but you are relying on your full attention to the gauge to catch any issues and you really should have at least some of your attention on driving.

Most CTSC were setup to run rich not lean, but with an OBDII car you are fighting the computer to much as it will react very quickly to the O2 sensors, there is little that can be done without additional piggyback or standalone devices to correct the fuel. I am not really sure what hardware you are running as CT had all kinds of bandaids over time to deal with the fuel issues on these cars, Shad will know what can be saved and what should go. I am sure Bisi can take care of the FIC and tuning if you decide to go that route.

Dave

 

[SuperSonic]

Thanks dave. Ill try the obd reader when i get the a/f guage hooked up so i can see both the readings. Like i said im not the most knowledgable on f/i stuff. I was under impression i could just increase the fpr a tad to increase the fuel across the curve to get the the entire thing down. Bisi said he would like to see it just a little lower, not much. He said i was on the border of what was good to him and that i could get 3 or so more hp if the fuel mixture was lower. The old ctsc i have doesnt have any tuneable stuff like the new ones have, so bisi recomended a reflash but i was unsure if anyone did that. It was great to get my car there. After the first run my ears went numb from the high pitch sound lol. Anyways thanks for all the imput guys.

And for those that asked where to tap a boose line bisi said i should tap my fpr line as it is boost controled to get a more accuraye reading than using the extra line off the tb.

 

[LMR]

Thanks dave. Ill try the obd reader when i get the a/f guage hooked up so i can see both the readings. Like i said im not the most knowledgable on f/i stuff. I was under impression i could just increase the fpr a tad to increase the fuel across the curve to get the the entire thing down. Bisi said he would like to see it just a little lower, not much. He said i was on the border of what was good to him and that i could get 3 or so more hp if the fuel mixture was lower. The old ctsc i have doesnt have any tuneable stuff like the new ones have, so bisi recomended a reflash but i was unsure if anyone did that. It was great to get my car there. After the first run my ears went numb from the high pitch sound lol. Anyways thanks for all the imput guys.

And for those that asked where to tap a boose line bisi said i should tap my fpr line as it is boost controled to get a more accuraye reading than using the extra line off the tb.

Call Shad. If it can be done he can.

BTW How many PM's have you got about your avatar:biggrin: