Fast GTO

This is going to be decided once back to back dyno runs are done...which I'm not sure will matter much with the FAST LSX intake on the horizon.

98Z28CobraKiller

iTrader: (17)

With the FAST, I was shifting at about 6800-6900. I tried everything between 6800 and 7300 and was within a tenth. Higher shift point yielded best results but the 60' is a huge problem. 1 tenth in the 60' is 2 10th's out the backdoor. This accounts for half of the problem. I suspect that with a gear and converter change, it could work out nicely but I'm not willing to do that.

I will fix my FAST tomorrow and have it back on for Friday or next Wednesday and peel off some passes just to make sure that there isn't another problem. Tune is spot on and AFR's were between 12.5 and 13.0's, same as before (after retuning it on the street). Timing was solid at 24* and even tried giving it another 2 degrees down low which didn't help at all.

I will try to get on a chassis dyno and get a power curve in the next couple of days. Maybe spin it to like 7600 RPM.

DrkPhx

iTrader: (15)

Did you do any tuning or datalogging?

3fingas

iTrader: (16)

Im surprised so the 60' is coming up a little short? How hard are you leaving? I forgot what converter ur runnin.

Tony Mamo @ AFR

iTrader: (13)

Thats where the shorter runners where likely going to hurt the combo....this isn't surprising at all actually.

I have seen some shorter runner manifold testing where the only thing accomplished was a big loss in low and midrange torque with zero appreciable gains in power (and sometimes losses upstairs as well). It's not always a given that a shorter runner will make more power higher in the RPM curve....alot of other factors come into play. They may be tooo short and an inch longer might have made all the difference. Tuning/designing manifolds is a very complicated science that requires a ton of hardcore dyno time and experimentation.

Whats most troubling to me is the trap speed down so much....60 foot times dont effect trap speeds.....only ET. Trap speed is simply power to weight ratio....the simplest and most effective way to determine whether peak power is up or down besides hitting a dyno. That much lower trap is indicative of a big drop in power....50 HP assuming the same density altitude (which is a BIG variable here guys).

Hence we are back to my first suggestion where I emphasized the importance of first getting this new combination on a chassis dyno....tracks have too many variables and we need to see and compare power curves.

Carlos....give me a buzz manana at AFR if you have a minute....and dont throw in the towel just yet, but lets book some dyno time sooner than later if you want some real answers.

A+ for effort man....a lot of people were rooting for you tonight!

-Tony

3fingas

iTrader: (16)

Well tony ur right, Im surprised he didnt pick it up on the big end. I actually have the same issue (or fate) down low. LS3, gmpp spider, accufab 4150. I dont start picking up pwr till 4400 thru 7300 which forces me to leave harder and higher. I agree that some drum time would be good.

silverbeast

iTrader: (16)

damn that does suck. 4 mph is huge. I just sold my ported fast and went with a ported GMPP intake and accufab 4 bl throttle body for my car. I hope it dosent turn out to be a mistake. Good luck getting yours dialed ln Carlos

miami993c297

iTrader: (6)

Hi Carlos,

Hygrometry is an important factor on track, and yesterday night humidity was very high in South Florida.

Over-all your VE table might be an indicator already...and you may expect to monitor some changes where the intake is adding or missing.
Versus VE don't hesitate to rebalance your Timing Tables.
Higher VE meaning more efficiency, following the rules you will have to diminish your timing in those places and go the opposite way with less VE.

Ideally, you always want a reference point for any compare (dyno are good for that purpose!!!) and the ET of other competitors last night (meaning they run their cars in constant conditions without modifications time to time) might be a good starting point to understand how Moroso performance was last night.

I am not in engine design enough to know what kind of effects this intake will produce vs. a FAST, but it is obvious that it is changing many parameters that needs to be considered.
Mainly, congratulations to open new directions in a so controlled way with honesty and for sharing your obtained results.

Christian

JL ws-6

iTrader: (50)

I'd be curious to see on a dyno what you see with a fast vs this intake, the track results are dissappointing to say the least.

Making me, and probably alot of people look @ other options that's for sure.

Definately try to get some dyno results with both intakes on the car, that will definately tell the story. I was originally supposed to do that test, but it never happened... at this point I'm kinda glad.

speedracer5532

iTrader: (8)

Carlos, do you happen to know what the density altitude was last night and the last time you ran? That would take alot of the weather questions out of the equation.

Loudmouth LS1

iTrader: (10)

Another buddy of mine in a heads/cam Z28 was out there last night, his best mph is perfect conditions is 119, he was only a little off from that last night, 118 - 118.5, so the air couldn't have been too bad.

98Z28CobraKiller

iTrader: (17)

Yes and yes. Anyone that has HPTuners is welcome to look at my log.

LS1tech wont let me post the config file to go with the log. If anyone wants it, give me your e-mail address.

miami993c297

iTrader: (6)

Hi Carlos,

You have already my email address...send it please.

Christian

98Z28CobraKiller

iTrader: (17)

Well that's another thing. I always launch at 4K RPM but normally my converter will flash to about 5K once I let go of the button and floor it. Because of the lower torque, converter was only seeing about 4450 on the hit.

For those that are confused about this, for some reason I have never been able to go to the top of my transbrake. At about 4200 RPM or so, the car pushes thru the brake, so I have to launch below that regardless of spray or NA. But that's another problem that really hasn't been an issue. It would be nice to be able to launch higher than that on motor but it works out fine for the bottle.

Regarding the MPH being indicative of horsepower, I thought that was only if the car spins. If the car isn't getting into the powerband until after the 60', the track is that much shorter for me to build any kind of speed out the back door. This thing really comes alive at 6K but I'm past the 60' at that point and every shift puts me down below that power band. I'm at 6200 going thru the traps in 3rd which is right about where it starts pulling. I think that with a 6K stall converter, a 4.55 gear and an 8K RPM redline, this thing could work out nicely. That or maybe with some boost.

I'll give you a call after you've had a chance to drink your Mocha Frappuccino this morning.

The more I think about it, the more I want to put my FAST back on and be done with it. I ******* HATE TURNING WRENCHES! The only reason that I do this stuff myself is that the car would be running high 11's if I had to pay for labor. I know that the carb intakes pretty much behave the same as this one so I'm not sure that I want to go thru that whole exercise just to see the test for myself. Perhaps someone with a shop and a dyno would like to tackle that. If I was being paid to do it, then that's a different story.

I really do appreciate the offer though Dev.


No FAST LSX on the horizon for us cathedral port guys.

I was actually taking that into consideration. We have a pretty tight group and I was looking at others time slips as well. Everyone that was hooking and running well was within .05 ET and .5 MPH. I never cracked 125 MPH last night and only just hit 100 in the 1/8. I'm usually around 103.

You've got mail.

WKMCD

iTrader: (2)

This is really dissapointing.

Thanks for the effort and info Carlos.

Kevin

speedracer5532

iTrader: (8)

I think one thing to remember is this is the short runner intake and I think everyone would agree that a longer runner would work better in a N/A application. I can't wait to see the results of the guy with the twin turbo 427 that bought one test this intake out.

Ericbigmac83

iTrader: (19)

Well damn, i was all excited to open this up and see some good numbers this morning. someone get some back to back time on the dyno to see if we can justify the crap track times.

miami993c297

iTrader: (6)

Hi Carlos,

Was your MAP value similar to those one from the log of last night with the Fast, specially above 6200rpm???

Christian

Drewstein

I was about to pull the trigger on this and test it out for everyone but the results have me a little scared as well.

Will the short runners affect FI positively or negatively?

98Z28CobraKiller

iTrader: (17)

They are a little lower with this intake. Usually between 98-102 with the FAST.

Here's one of the last passes that I made with the FAST. Disregard the WBO2 spikes. My sensor was going out on me and I replaced it since then.

It should rock under pressure.