Seems a little low to me as well... I think there is another 15-20rwhp hiding some where...

 

Post the dyno graph.

 

Might be a lil low but I did about the same.. 422rwhp 395rwt with AFR 205 61cc kooks headers with cats, ASP pulley, lid, Fast 90/ Nw90MM tb, f4 226/226 575/575 114lsa cam and a 85maf thru a slp exhaust with a Magnaflow muffler. I'm gonna get Nick Williams to drop in a G5X2 in it to see if we can drum up a few more ponies. Hope you find out whats holding you back and good luck on the track.

 

Went to the track this morning, only got two runs in because of a big event the track had. Long story short only gained 2 tenths and 4 mph.. Granted the weather was worse than I 've ever raced and I'm still experimenting with shift points, but overall am seriously dissapointed with the performance. The car really seems much faster on the street and the RWHP numbers are up about 80 + hp. I guess I'll wait for better weather and maybe better tuning before I consider the high dollar H/C a complete bust. But overall feeling a little foolish for my high expectations.

 

Lets see if I can make you feel a little better. I think you said 426/400 before the 90/90? With 90/90 you picked up 12/2 now at 438/402. Yes that is a bit lower then the 215's should be making. Heads are 215's 62cc, your compression would've been higher if they were milled to 59cc like my AFR 205's. Its a hard call, but my educated opinion would be you have a very safe tune installed and maybe a little too safe. Get your tuner to play with the tune a little bit, and BTW what is your A/F ratio?? Mine was 12.6 to 1 and when it was leaned out to 13 to 1 I picked up another 13 rwhp and 11 rwtq. I think I was richer then 12.6 to 1 but I am dead on at 13 to 1 now and she's a beast. Look at my sig for all my goodies and what LG did to my car to make her what she is. Good luck and your car is probably a lot better then what you are giving her credit for.

 

Thanks for the reply. I probably should have told every one but when the #'s came back on the 90/90 setup I promptly told the shop to put my old stuff back on. $1300 on 12hp and 2ftlbs aint exactly worth it. That coin puts me half way to a new rear end. As far as a/f I think it's above 13 to 1. But I have to agree that part of the issue is the tune( timing maybe).

 

How much spark advance? Any knock? are the injectors over 100% duty?

 

What legnth Push Rod's did the company install? ET's require a good bit longer PR. I would like to know which spring were installed just to verify that they are adequate. The Yella Terra's place alot of extra strain on the valvetrain, so they could be over working the springs. IMO, if you felt the FAST was a waste, then I'd have them yank the Yella Terra's to. The stockers are about the best bet for our valvetrain. Your cam should deffinatlly peak higher, so I feel there is something wrong. If you find the problem, you should revisit the FAST.

 

what are you running for an exhaust? There's been no mention of that.

the rocker arms, those are a known potential problem maker, I'd yank those off and put the stock ones on, see if that gets you anywhere.

 

The other members raised some very good points that I omitted due to the length or my first response to your post. Several questions, how many degrees of timing advance?? I am running 28* with 0 KR. How many degrees of timing advance are you running? What Injectors are you using? At your power level you are probably beyond 80% of your duty cycle and should be running Ford Racing SVO 30 lbr's or a GM comparable like 36lb'rs or even 38's. Springs should be a dual valve spring setup like the 921's I have or something comparable like the Patriot Dual Golds would work fine too. Your rocker arms as previously mentioned are most likely overworking your springs. I am using my stock rockers, no problems at all. I have 7.4 hardened PR's and using the AFR 205's milled to 59 cc. I believe your heads need a PR with a little more length. My compression is right at 11 to 1, what is yours? One other comment on springs, my friend had more spring pressure then he needed, could've run the comp 921's safely without issue but had the stronger 977's installed instead. He too was disappointed with his #'s. After numerous complaints to the shop that did the work, they looked over his build sheet and found that using the 921's would have been the better route. After install the dyno showed a 5 rwhp gain if I remember correctly. The issues on the tune were next and they added 2* of timing and instructed him to use a reputable 93 octane rated fuel only to avoid any issues with KR. With all said and done he picked up 15 rwhp between the retune and the spring change. Again I hope this helps. Please post up the results when you get some answers to these questions. Consider getting a Meziere EWP to free up another 7 rwhp and better gas mileage. GOOD LUCK!

 

I currently am trying to get some of the tune spec's together to post here. I know that longer pushrods were used maybe 8.1's. Exhaust I have hooker l/t's , no cat's,20" bullet muffler and loud mouth. I also have stock injectors which many post's on this site and other reputable sources claim are ok at these power levels. Why are the yella teras hard on springs? They are supposed to be stock ratio. As far as springs they came from ET and are crane's version of the 918's from comp. Thanks to every one who has responded---- Keep them coming I need all the advise I can get.

 

I have no clue then.

 

The springs are probably not up to the task... are they singles?

The problem with the yella terra rockers is their weight, it puts alot more stress on the springs then the factory rockers do, so if your springs are marginally safe for the cam you are running, those rockers will push them over the edge and create flating issues. If the power climbs to a certain point, then just stops and gets choppy, that very well could be valve float. As for the factory injectors being o.k., that all depends on who you talk to. I don't personally think it's a real good diea to push them too much past the 420 rwhp mark n/a, depending on the car, that sould be putting them into a pretty steep duty cycle. It's kind of a rule of thumb, that if the injectors are over 85% of their duty cycle, then they need upgrading.

There's more power in your setup, the exhaust sounds like it's fine, I doubt that there's much in the way of power to be gained there, so I wouldn't really look there. It's in the valvetrain/tuning I'm sure of it.

I'll bet that once you have it strait, you'll be well over the 450 rwhp mark... and that fast 90/90, I'd get that back on there, I know it doesn't seem like a great power gain for the $ so far, but I bet once you have the other issues sorted out it will make alot bigger difference.

 

Thanks I'll try your suggestions.

 

Good luck with it, post back up once some changes are made and let us know how they worked out.

 

You should really post the dyno, it may not be the rockers. At this point, there is a lot of educated guessing going on, but the curves might help narrow things down.

 

I hope you figure out the issue. i kinda hoped mine pushed out another 10hp tq, but id definatly keep the 90mm fast. im gonna ditch my HS rockers and have my stock rebuilt and see if that makes any difference

 

Did they check your fuel pressure? At that hp level my fuel pressure was dropping to low 40#. Also you are most likely running out of injector. Look into a Ractronics Plug and Play and 30# SVO's.

 

ya im running 30# injectors. im thinking the TEA port job on my 90mm intake might be costing me big time