Interesting Josh. We were both down at Cecil last night.....maybe you might of seen me running - I believe I was the only Jeep SRT8 running. Thankfully, track conditions are out of the equation with my Jeep. Traction is a non issue to date.
Actually, I'm seeing a decrease. Dyno is next and we will be able to do some swapping of parts and play around with the configuration and tune. More to come soon.
Keep us posted on your before/after dyno tests. I hope to dyno test a GM LS2 throttle body within the next week and I will report my findings. Soon, we will know if these 90mm throttle bodies are worth any power on mild 6.1L Hemis.
90mm I have swapped them back and forth on my 426. I have had some real tuning issues to begin with that Dave from B&G has fixed.......but thats another story. The 90mm throttle body causes idle quality issues and I believe it is the way the blade is set at idle. I dont believe you can just swap the throttle bodies without at least reloading your tune so all ECU functions reset including the throttle body calibrations. After reinstalling the stock throttle body that last little idle and driveability issues were much better. As far as opening the manifold/throttle body opening........if you have stock heads and cam your wasting your time IMHO. I had the stock manifold flowed and each runner flowed 290cfm. If your heads are ported to flow 350 or more the manifold is a bigger issue than the throttle body. I think to many are missing the real issue with restriction.
I would say you are exactly right Steve...the stock TB most likely flows more than is necessary for a stock manifold and head package...
I have dual tbodies and my observations are that the throttle response is much better. I have swapped back and forth and can't go back to a single tbody. I have a 426ci with Mopar heads and a pretty big PPP cam. I think the a/f ratio may be fine when the PCM has control due to 02 sensors. The question is WOT a/f ratios. Also, if you find your a/f getting richer at higher rpms at WOT, it could be that the tbody motor is being pulled shut by the air velocity. If it is gettin lean, then the predator needs to be used to add fuel at higher rpms at WOT. C.
Mark your 12.66 run on march 29th was -1767 DA at cecil county dragway, your 12.716 on april 30th was +307 DA cecil county dragway. Thats your biggest difference definitly not an apples to apples comparison. Your runs corrected as follows: Actual 12.66 @ 107.10 = Corrected 12.895 @ 105.07 Actual 12.716 @ 107.50= Corrected 12.67 @ 107.85 In theory you would have run a 12.41 @ 110.19 if you would have run your truck at exactly the same DA after the Arrington 90MM throttlebody, BWoody 4" CAI, and BWoody P&P intake manifold.
Most dyno tunes with the Predator shows us always ADDING (+) fuel above standard PCM settings and there is a limit of how far we can go. I fear there may be some hard coding into the PCM that is set at some max flow calcs based on the stock TB. Has anyone ever owned a F.A.S.T. module with a throttle body? Are there settings in it related to TB size?
Well I think Mr. Dragstrip genius Mike has a good point here....I never even thought about that! :clap: Good points Mike...
This is exactly why I like to perform the swaps on the dyno whenever possible. The weather correction gives a more true A-B comparison. At the track, the weather conditions (and track conditions) can skew the results a lot more. I hope to do an A-B comparison of the GM 90mm TB on the dyno in the next 2 weeks. Hopefully, we'll find some hidden ponies.
LOL...Not a dragstrip genious by any means, i just know when to go to the dragstip and when not to....lol. My opinion this throttle body along with a ported intake manifold and a 4" CAI is good for 2/10ths on a stock motor, on a 426 it has to be good for 3-4/10ths. If it is worth it to spend $1000 thats your call, Mark spent almost $2000 for this setup with supporting mods. Thats $1000 per tenth, not bad in my opinion. Remember the faster you go the harder it is to squeeze 10th's out of your setup. Hell I know plenty of hard core racers that pay upwards of $10K for a 10th once they get in the 9's!!
I read a lot of posts that say putting the 90mm TB on a basically stock car is not worth doing. Then I read this thread below that says there was a dyno confirmed 17 hp gain realized after installation of the 90mm TB on a basically stock 6.1 (with CAI and tune). To me $52.64 per unit of hp gain is a pretty good value even for the billet version of the TB on a stock car. Once the non-billet unit is released we will probably be looking at closer to $35.00 per unit of hp. Why do so many think that this is not a good mod for a stock 6.1? Do you not believe those gains or do you feel that is too much to pay per unit of hp? http://www.srtconnection.com/forums/showthread.php?t=2986&highlight=90mm
