We sell BIG BORE performance throttle bodies
Or we can bore your stock LT1, TPI, LS1, Mopar, TBI throttle body others
Who are you guys and is your product any good?
I am glad you asked. We have been boring throttle bodies and doing performance work on SBCs for over ten years now. Our work is bought and resold by several local companies as their own - so we have to do quality work. We specialize in LT1, TPI, and TBI motors and don't do FORDs. All our throttle body work is performed on and Bridgeport mill which allows us to hold tolerances to 1mil or better (thinner than a human hair). This means you get a solid performing part that will last for years.
What motors do you recommend this for?
Simple Question - how does up to 460hp sound? Or, basically anybody that is looking for more power. If you are reading this, then that probably means YOU. These throttle bodies will yield a small improvement to stock motors, and really wake up your hot 350, 383, or 406. Low RPM tire spinning throttle response will be improved as well as top end power potential. The twin 52mm throttle body will support motors making upwards for 460hp, the 48mm bores 360hp on TBIs.
What is your throttle body bearing upgrade and why do I need it?
We perform our throttle body bearing upgrade on ALL throttle bodies we rework/bore. Do you currently have an unstable or high idle? Then you need throttle shaft repair / bearing upgrade. The GM throttle body is a great piece from the factory, however, with mileage the throttle shaft bore wears out which can lead to two problems. The worn and loose fit of the throttle shaft is a vacuum leak and second because the throttle shaft can wobble around, the blades can bind against the casting at idle thus sometimes closing completely, sometimes not. The end result can be an erratic idle, or high idle all the time. We clean up the throttle shaft and then use a high quality undersized throttle shaft bearing and seal in the Tbody casting (undersize to compensate for any wear of the throttle shaft). The potential for vacuum leaks is eliminated and the throttle blades return to the exact same spot every time - CLOSED. This means you get a consistent and stable idle.
I want one now! What do I do?
Great, Check our ebay listings for a "BUY IT NOW" auction for your vehicle - simply purchase that item and we usually ship within two days of payment. If you don't see your application listed, email us and we will get an auction up for you. Shipping and handling is $9.95 to the continental US (48 states). Canada, Hawaii, and Alaska is higher.
What are your payment options?
We accept Money Orders, Cashiers Checks, Personal checks (must clear before ship), and paypal
How much air flow can I expect from your throttle body?
These #s are based on actual flow bench data and other published sources: 52mm LT1/TPI - 750 CFM (versus 630 CFM stock. 50mm TBI - 750 CFM (versus 420 CFM stock). Our 50mm TBI includes an aftermarket injector spacer, a modified throttle linkage (i.e. cut down) and special modifications to the casting to achieve 700CFM
I have an airfoil - or I want an airfoil - Will this throttle body work with an airfoil?
Most situations - YES. However, since most of these airfoils are designed for 48mm bores, they will be a little restrictive on one of our 52mm units. Our solution is to match bore the airfoil and throttle body together - we will match bore your air foil no extra charge on one of our upgrades, so send it along. NEED and Air Foil - We can add a matched bored airfoil for $35 with any of our throttle bodies.
I am on a budget - what do you recommend?
Best bang for the buck is headers/exhaust, bigger throttle body, and 1.6 ratio roller rockers. This should set you back about $500 (if you shop on ebay). Next we would recommend a bigger cam. If you need more, well, you probably know the rest
How big do I need?
Depends. Actual needs will vary based on YOUR engine setup, but the maximum you can expect from each throttle body is: 52mm LT1/TPI is good for 350/383/406 cubic inch motors up to 460hp, our 54mm LT1/TPI throttle body is good for 525hp, and our TBI is good to about 375hp. These numbers are theoretical maximums and based on potential air flow versus RPM calculations.
Do I need to port/bore my intake manifold?
In most cases - NO. The LT1 and TPI manifolds are already bored to 52mm - every thing matches up nice. The stock TBI manifold is bored to 1.80" (46mm) and will flow match nicely with our 50mm TBI throttle body. I most cases you need only chamfer the bores of your TBI manifold for the throttle blades to clear. The flow potential of your TBI manifold's "open" 46mm bores flows about the same air as a bored 50mm TBI because of air restriction caused by the throttle blades/shaft
How much power will I gain?
Tough to say, again every application is different. Stock motors will gain 10-15hp with noticeable improvement in torque and throttle response. About 40hp over stock if you add headers/exhaust and 1.6 rockers. Anything beyond that is impossible to say, but add a mild cam upgrade to what you have already and 100hp over stock is not out of the question with good idle and gas mileage. This assumes you don't have a restrictive intake or heads (such as the GM TBI head castings)
Why would I buy your TBI tbody and not a GM 454 BBC throttle body?
Simple - two reasons. You like less work don't you? First, we can provide a TBI throttle body that exactly matches your stock throttle linkage and sensor/IAC setup. No scrambling to find correct cables, brackets or connectors, just bolt it up and go. Also, most 454 BBC throttle bodies have a different idle circuit than the small block units (If they have one at all) and the throttle linkage will probably be different. Problem is that your ECM is tuned to a specific idle circuit including size and shape, any deviations from stock design and your vehicle won't idle correctly - especially when the AC compressor cuts in/out. With our modified SBC throttle bodies, you get a throttle body that matches your vehicle including linkage, sensors and idle circuit.
Why does your 50mm TBI flow 750 CFM when a big block TBI only flows 670CFM
We have flow tested our 50mm TBI throttle bodies using a stock BBC 2" throttle body and find ours flows more air. Why you ask, first, we machine down the throttle shaft from .375" diameter/thickness to .150", and second you can add our injector spacer which both add up to much greater air flow potential. Third, we remove the "air horns" from the top of the TBI - aka "ultimate TBI modifications" and smooth this transition
Why do so few offer a 52mm TPI tbody and why more expensive than an LT1
The TPI throttle body requires more machine operations. We have to plug and relocate the EGR circuit for proper operation. This is a tricky procedure that can ruin the throttle body if not done correctly. Actually the $20 additional we charge is bargain when you consider the extra work involved
I have a supercharged LT1/TPI motor - what do you recommend
Our 52mm LT1/TPI throttle body is an excellent match for you SC motor if the throttle body is downstream of the SC - i.e. the air flow is air filter- to SC to throttle body to intake/motor. Horsepower is only limited by how much boost you run - hence the whole concept behind the SC. While you can make good HP w/ a stock 48mm throttle body, the more intake restrictions you remove, to more HP you can make. Thus, installation of a 52mm throttle body is recommended
Will this work on my '92-93 LT1 automatic?
Yes, we have throttle bodies for you car. However the '92-93 is a unique throttle body for that application only. That is why the core is $60. We can also bore your '92 LT1 corvette
What is your 53.5mm LT1/TPI throttle body?
Glad you asked, we have gone to the extreme for these LT1/TPI throttle bodies. We start w/ select casting #s and bore them to the MAX - 53.5mm, we then installed new custom throttle plates and the result is 825CFM for up to 525hp motors. These are available on a limited basis so get one fast if we offer it. Please don't ask us to go any bigger, you can't unless you want to spend $350 on a 58mm
My throttle body is worn out - can I still trade this in for credit?
Yes - All throttle bodies we rework receive our bearing upgrade so we don't care - send it on. All throttle bodies must be complete to receive core credit.
Do I need bigger injectors?
Probably not unless you are making major modifications such as increasing displacement, radical cam or head porting. Use the following formula to estimate injector size: (Injector Size Needed in lbs/hr) = (Expected HP X 0.625) / (# of injectors) Keep in mind this is only a rough calculation. This calculation can be applied to any motor including TPI, LT1, and TBI fuel injection.
Will I need a custom computer chip?
Most TPI and LT1 motors w/ MAF sensor will not. This is a very smart system and will adjust for the extra air you are letting in to the motor. The ECM will "learn" new fuel curves over time. MAF systems can even handle mild cam upgrades, headers and high flow exhaust. With MAP based systems (all TBIs and early '90s TPI/LT1s) you will need to adjust fuel pressure and add larger injectors to help compensate for the extra air. However, the bottom line is that for optimal performance, you will probably need a new PROM in your MAP based system. Same goes for radical changes to MAF based systems
Will this change my gas mileage?
OK LEAD Foot - This modification will not affect your gas mileage under normal driving conditions - we have verified this. So what does that mean, we find most people tend to enjoy their new found HP a little too much thus mileage can suffer in the real world. Have Fun
Will this affect my state inspection?
Technically yes, however since we use a stock casting, nobody will ever know. I won't tell if you don't
I have several throttle bodies - Can I trade these in for credit towards one of your bored units?
YES - Absolutely. Send one or twenty, we don't care and we will give you credit towards a new bored throttle body. Our credit schedule is the same as our core charges. I.E. - send in three LT1 throttle bodies, get $150 credit (3 cores X $50ea = $150). Core credit for TPI motors is $60, TBI throttle bodies varies from $10-40 depending on application