I've got a 750 blow thru from CSU to use on my build. It is still in the building stages so it will be a while till I can test everything. I originally started to build it with a B/W S400 75MM single turbo and went with the 750 figurung that the 75MM and the 750BT would be a good combination. I was figuring to be in the 1000 HP area. BUT, as a true motor head my engine build has gotten out of hand. I also made a killer trade, swapping the 75MM B/W for a pair of TC76 Turbonetics ball bearing turbos. My HP potential just took a giant leap. My motor will be capable of much more than originally intended and the twins will have the potential to make that happen. But now I'm afraid the 750 will hold me back. I'm looking for any experiences on total HP that was attained using a 750BT. Because of the intensified engine build (more money) the car build has spiroled up (more, more money) and the economy drop kickin' me in the arse, I will probably stay with the 750 for a while, if I even get it together enough to run it.
Anyway, looking for any info on the 750s limits. CSU advertises 1100hp potential. Has any one pushed one farther? If so how much and what was/is your combination. Thanks to all for your help. Mark L

 

best to ask kevin but i think he said someone made 1300plus. i had a 850 and couldent get enuf fuel could have been the too big cam but wont know till spring.
my afr with the 850 main was at 8.8 to 8.4 best on e85 with 100/100 jets 8pvcrs at .086 dual brpv. switched to the 750 main and i was pig rich at a 7.0 afr with 82/90 jets same everything else.
my motor is a 8.4:1 357. so i think the 750 will stay just have to test the smaller cam and both mains to find out.

 

I believe that HP limit is because of the single needle & seat bowls.

 

Thanks for the replies guys. And sorry it took so long to look back for them. Your mention of the needles and seats I wonder about because the 850 is advertised as capable of 1685 HP and use the same bowls and needles and seats, but I am not totally sure about that, I'm just assuming they are the same. Their site recommends the upgraded needles, seats, and bowls at 1400 and up. Since I bought the 750 carb from them (still have not used it) our area has greatly expanded the E85 availablility. So that is an option I really want to try. I wonder if the E85 diminishes the HP capability of the carb in any way, such as flow etc?? Next call is to Kevin I guess. Thanks again for your input guys. It is very much appreciated. Mark L

 

I'm running CSUs 750 on E85 with the dual needle and seats on a conservative tune the AFR are staying around 11.5 Had to put bigger hi speed air bleeds in to lean out the upper mid range and is working great. Making roughly around 1020hp on mild tune.

 

Nice black marks......Nice and long!!

 

On your e85 750 was your main bleeds sec blanks. Mine are and my mains come in too soon and I'm way rich so id like to lean it out. How big did you go on the bleeds

 

Not sure what size was in it. Know we went two sizes bigger than was in it. On the dyno the AFR was showing it was rich midrange so we put bigger high speeds in it and it cleaned up the upper end. The car was doing a lot of back firing when we let off the gas on the upper end showing we had a lot of extra fuel in the pipes. After changing high speed air bleeds it quit back firing out the pipes and dropped the AFR where we wanted them in the 11.3 range.

 

Just dropped in to say I sent a builder carb and my original 750 back in. The original is getting the E-85 treatment, and the builder carb is getting both the E-85 and blow thru conversions. So I should be more than capable of reaching my HP goals. Thanks again for the input guys. I may still need the info you gave if I have any tuning problems. Mark L