Hello,

My new 412 is progressing and I have TB questions, which brands seem to work reliably the best and what size should I opt for. I have looked at 58MM to the TPiS Monoblade. My motor build is a.30 over 400ci block that has been fully race prepared including o-ringed cylinders, all casting marks ground, billitt splayed mains, forged crank, H-beams and JE 11:1 pistons. the cam will be in the area of 607 lift 248 duration 112? lobe seperation. The heads are Brodix Track 1 with full port job(still in the works but looking at 300plus intake flow) the rockers will be Yella Terra 1.6 roller shafts. The intake is a MiniRamII being ported and matched to the heads. I still have to decide on the throttle body and the injectors. They will be working of a Haltech E6GM and still deciding on the ignition, I may go with billitt MSD and controller, or if I find a good DIS system with multiple coils I will go that way...the exhaust will go through custom 2 inch primarys with 3 1/2 collectors and a possible turbo install next year. I want to know what brands of throttle bodies you guys are running, and how they are working for you. I know my decision on size will be affected on the intake and head flow, but I am getting ready for the purchase early......

Sorry about the long post, I just know there are several factors that are needed.

Thanks

 

AS&M 58mm They will support 600 hp. Chris at SpeedDemon has them for $486. :cool:

 

I have the BBK/Edelbrock 58mm and can say that I am not impressed with the quality. My throttle will hang open occasionally and I understand that there is something that I need to grind off in the casting but can't remember what or where it is.

 

I have a friend that had a 401 in his z28 that had 490 rwhp. He used the AS&M monoblade. He said it flowed like 1300 cfm. This supported a 300 shot of nitrous that put down over 700 rwhp. The twin 58mm is supposed to flow about 1000 cfm if I remember correctly.

 

:yesnod:

Definately the AS&M 58mm from Chris at Speed Demon. I've shopped around, and he has by far the best price.


[Modified by 365ZUM, 9:57 AM 2/6/2002]

 

Th AS&M and the Holley are both very nice pieces. I run the Holley 58mm and a buddy has the AS&M. They are both CNC'd from a billet stock.

I seriously doubt you will need a monoblade.

 

I'm buying a Holley 52mm, VERY nice piece. I wouldn't have bothered, but a friend has the 58 with nitrous plumbing, that convinced me to buy it. It's so pretty, and the quality is very good.

 

I would be the friend with the 58mm NOS throttl body. I am very impressed with Holley's fit and finish. I would not trade it for any other brand.

 

Brent,

Do you have that Holley part number. I am interested in the Holley plumbed for NOS, just cant seem to find it on their site. My block is prepared with NOS in mind.

Thanks

 

I agree with above, the AS&M or the Holley .. they both look like GREAT pieces of work.

Nice engine build up BTW!!!

 

That's a great question, too bad I don't know the answer. I can't find it on the Holley website myself. I did e-mail one of our contacts at Holley, he should be able to tell me.

 

TNT, you wouldn't have a picture would you of what you have to trim. I know several people who have installed Holley throttle bodies and haven't had to trim anything. Thing is I don't know anybody who has installed one on an L98, maybe the TPS is different?

 

TNT,

How long did it take you to get the Haltech programed? Do you have a saved file that you could send to get me started??

 

Don't buy your throttle body yet. Advanced Performance has a new 58mm coming out that is also a billet piece. It also has sealed roller bearings in it so the shaft turns very freely unlike the Holley. I don't know the price yet but it should be very competetive with the others. You will not have to grind anything to install this and all fittings are removable in it. The air duct is also easy to slip on unlike some of the others it is very impressive.

 

?? The Holley units I've seen have been very smooth. Oh well, it's a little late for me, I pick up and install my Holley 52 tonight.

 

Not to speak harsh about them, but both Holley's I tested the throttle blades rubbed the housing and on the 85-88 I had to trim the TPS switch so it would not get hung up. The air duct did not fit and half of the threads were metric and some were standard. I was not impressed, however the as much crap everyone gives the BBK units, granted they are cast and don't look as nice they are one of the best. When you get your Holley unit tonight hold it up to the light and see if the blades seal all the way around, I bet they don't which is going to cause your idle to go up some. The blades should be fully closed in idle and the IAC which is controled by the ECM controls idle.

 

Not to go on the defensive, but mine does not have any of the problems that you suggest after the unit is installed and adjusted. Non-adjusted/out of the box, the blades did rub a little when in full closed position. One you install the TB and set idle, the blades are positioned so as not to rub whatsoever.

I traded up from a BBK 52mm to the Holley because I had heard of BBK problems with their 58mm unit. I was happy with my BBK 52mm, but it does not compare to the quality of the Holley unit. The only problem I have had with it is I broke off the tab of the return spring that holds it while I was trying to adjust it. Summit sent me a replacement without question.

 

Snaketr,

do you have a website that has the specs??

 

Prater,
I'm sorry as of right now they have not been released to the public but it should be towards the end of Feb or beginning of March. There is a sneak picture of one coming up in an issue of Corvette Trader. I can answer any questions you have on them but what specs are you looking for?

 

I re-read your post Snaketr, you covered my questions, but I really want something proven and so far looks like everyone is happy with the Holley and AS&M products.