How am I getting this far on 75 lb. injectors? #'s don't jive.
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Turbo-Archie
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So the VE should be higher then?
Well, Cal said that the VE #'s were not that suspicious. He has tuned many cars that did not require very large numbers in the upper cells. The car is 3570 lbs, which is not not is heavy as I thought it was since the only lightening up I have done is an F body rad, wheels and slicks, and TA heads which are only 20 lbs lighter than irons for both.
I may be worrying about nothing, but I just think that it is strange that I am only using 80% of these 75's, since I have seen many combo's with 72's and 75's maxed out at of before 10.0's
I may be worrying about nothing, but I just think that it is strange that I am only using 80% of these 75's, since I have seen many combo's with 72's and 75's maxed out at of before 10.0's
I think norbs is right, for whatever reason you just have a nice efficient engine. Not efficient as in high VEs, which is an indication of breathing, but efficient as in converting fuel into hp (ie BSFC). You might be moving less air than someone else, and therefore needing less fuel, but getting more hp our of it.
Two engines can move the same amount of air, and therefore need the same amount of fuel, but make greatly different hp out of it.
So what is so great about your engine that would make it more efficient? Combustion chambers that much better? Higher compression than typical? Timing is highly optimized? Great ring seal? Something else?
6000 rpm, 27ish psi boost on a 231 with 75s @ 80% DC seems pretty reasonable to me. Is that about what you're running?
John
Two engines can move the same amount of air, and therefore need the same amount of fuel, but make greatly different hp out of it.
So what is so great about your engine that would make it more efficient? Combustion chambers that much better? Higher compression than typical? Timing is highly optimized? Great ring seal? Something else?
6000 rpm, 27ish psi boost on a 231 with 75s @ 80% DC seems pretty reasonable to me. Is that about what you're running?
John
6300 through the traps. 25 psi (no BS) crept to 26 at the end of the run. 24* timing. 231 ci 109 block.
Maybe you are right. Just seems to run better than I thought I could get by on 75's.
But I think the heads must be working well (thanks Nick M). They looked and flowed good. Chambers were smoothed. Plug placement is close to the exhaust valve. The rings seem to seal well, gap is .021 primary, .023 secondary. Compression is 9.1:1. Pistons thermal barriered and dry filmed. Cam has 4* ground in, installed it's 3* advanced.
Sometimes you just fall into conventional thinking based on what you have seen before.
I just thought it was strange that I had stretched these injectors this far, and still had a little room to play.
Maybe you are right. Just seems to run better than I thought I could get by on 75's.
But I think the heads must be working well (thanks Nick M). They looked and flowed good. Chambers were smoothed. Plug placement is close to the exhaust valve. The rings seem to seal well, gap is .021 primary, .023 secondary. Compression is 9.1:1. Pistons thermal barriered and dry filmed. Cam has 4* ground in, installed it's 3* advanced.
Sometimes you just fall into conventional thinking based on what you have seen before.
I just thought it was strange that I had stretched these injectors this far, and still had a little room to play.
750H.P.V6
Brutal 6 Racing
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Stu,
First off I wanted to say congrats on your performance. Your car is really flying!! Kudos all round! Secondly, I agree that your injector size is small for the H.P. level you're at. Here's the math I'd go by 75lb injectors X 6 with a break specific fuel comsumption of .5 will support 900 H.P. at 100% D.C. Since you state you're only at 80% that would only be 720 H.P. and you're making much more than that based on the car weight and trap speed. Are you sure they aren't 96 lb injectors?
Neal
First off I wanted to say congrats on your performance. Your car is really flying!! Kudos all round! Secondly, I agree that your injector size is small for the H.P. level you're at. Here's the math I'd go by 75lb injectors X 6 with a break specific fuel comsumption of .5 will support 900 H.P. at 100% D.C. Since you state you're only at 80% that would only be 720 H.P. and you're making much more than that based on the car weight and trap speed. Are you sure they aren't 96 lb injectors?
Neal
disco stu said:The car is running 9.7's, 9.8's at 139 MPH on 75# injectors. VE#'s in the low 80's, A/F 11.3, and get this... 80%ish injector DC.
I have a hard time believing that.
rodman99999
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I believe they had to redesign the heads so they would fit in the third gen F body, and in the process made it flow a bit better as well. Having them massaged had to help quite a bit, and headwork usually produces the best gains available on any engine. There aren't that many of us running those heads(kinda rare), so: not alot to compare with. Great numbers!! Wanna sell your heads? 
750H.P.V6 said:
Thanks Neal.
I think I can pick up some ET on the 60', and then I am gonna leave it alone, for now. I am pretty sure Jack at RC sent me the right injectors when I ordered them a few years ago. I was running them on ME-R and it ran fine so they must be what the chip was burned for.Can't confirm by looking at them, the dang Delphi's all look the same. I think there were #'s engraved in them, I think I will take a closer look and give him a call anyways.
Sorry Rodman, don't want to sell the heads.
The TTA heads did flow a little more I believe. Sorry for the confusion, but the heads I am using are the TA Performance Street Intimidator aluminum heads.
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