got a relatively good deal on a ZZ4. going infront of a T5 and I need a carb recommendation. was thinking Holley 650-750DP. but don't want to overcarb as this will be mostly street driven. GM recommends 750VS, I went on Holley's web site and they also recommends a VS carb? 650 I think?

Also was wondering about linkage and choke? car is originally a L03. I read the FI to carb tech article and it mentioned I'd need to fab something up for linkage. Any help would be greatly apreciated.

Thanks
nick

 

A 650DP with an electric choke would be fine. With an electric choke the only linkage you need to worry about is the throttle, which is no problem.

 

Thanks Apeiron.

yeah, I was asking about throttle linkage. sorry if I worded that weird. so your saying my TBI linkage will work?

 

I don't know if your TBI cable and bracket will work, but at worst you just need to replace the throttle cable and buy a new bracket. You don't have an automatic so there's no TV cable geometry or anything to worry about.

 

so this is what I'm looking at:

carb: http://www.holley.com/0-4777C.asp

choke kit: http://www.holley.com/45-224.asp

Figure I’ll need the installation kit: http://www.holley.com/20-124.asp

and dual feed line: http://www.holley.com/34-150.asp

what about the throttle cable bracket?: http://www.holley.com/20-88.asp

and what about tuning - I assume it will be alright out of the box. can I tune it at a later date? suposed to come with a tuning DVD but will I also need to purchase a tuning kit?

please bear with me - this will be my first carburator. Thanks for all the help.

nick

 

It'll run out of the box, but you'll need tuning to get the most out of it.

 

I just read the ZZ4 installation manual, and confirmed GM recommends a 750 vacuum or mechanical secondary carb. If I go with a 650 will I be holding the motor back much? I assume I'll have better street manners with a 650, but wouldn't a properly tuned 750 also be good? basically what are the pros and cons of each. Thanks for the help.

 

Pro-System Carb-----Knuff Said

http://www.prosystemsracing.com/index1.html

 

for a street car - daily driver? They do look nice, and they do have "crate motor" carbs, but the cheapest is around $600 for a 4150. Thanks for the recommendation, but I think I'm going with a standard Holley. What about a 700DP as a compramize?? any thoughts??

 

GM makes their recommendations to protect the general public from the "bigger is better" mind-set.

A 650 is "big enough" to produce the peak torque, but a 750 will probably produce high peak power. With a T5, a double pumper is critical. VS will not close immediately when the throttle is closed, which will cause havoc with a T5 when trying to shift as quickly as possible. If you never do that, a VS would be fine.

For the DP choices, 650 would give you the best street manners (600 even better), 750 the highest peak HP. 700 would be a compromise between the two.

 

so GM used a 750 to get the highest rated HP/TQ numbers, and that is also what they recommend. But I'd probabbly be better off on the street with something smaller? I think I'll go with the 650DP since this will be primarily street driven. will I be able to use the throttle cable bracket I linked above with my TBI linkage? Thanks for the help.

 

GM used a 750 DP to get the highest HP #, 650 DP to get the highest torque #, and recommend a 750 VS. That should tell you something.

I don't know that you "need" that throttle cable bracket. I've heard several people say they used their stock TBI stuff.

You will need a throttle valve corrector bracket on the carb throttle arm, such as SUM-700202 from Summit.

I don't believe the studs in the installation kit will work, either.

 

Thanks 5-7 & Apeiron

you mean to mount the carb, or for the throttle bracketry? If I can't use the studs in the installation kit - what do I use? I assume I need some of the parts in the kit, i.e. gaskets, air cleaner stud, throttle cable ball. I want to make sure I get everything I need for the install before I actually start. Thanks again for all the help.

nick

 

Sorry, I meant the throttle cable studs.

The corrector bracket will have the TV cable mount. I'm not completely sure what the TBI throttle cable looks like.

 

sorry for the confusion - this carb stuff is all new to me. Do I need one of those in-line fuel filters by the carb? or is the stock one by the gas tank enough?

 

the one at the gas tank(inline > should be good but it wouldnt hurt to run another one

 

Thanks Badass355. I think I'll stick with just the factory filter for now. I actually just got off the phone with summit and ordered everything. Motor came in today too. can't wait.

I was wondering about the throttle valve corrector bracket (SUM-700202) that 5-7 mentioned. I ordred it, but the tech said that it's only for cars with 700R4's? and that I shouldn't need it. I also got an assortment of throttle studs so hopefully one of them works.

 

if its for the 700r4 u shouldnt need it.....how much did that run ya?