Chevy Impala SS Forum banner
1 - 20 of 39 Posts

·
Registered
Joined
·
141 Posts
Discussion Starter · #1 ·
Hello again everybody, I have a 1996 Impala which I purchased maybe six months ago and currently the car has the K & N cold air filter, Flowmasters, and I just recently put some Edelbrock Headers. With these basic engine modifications if I get a 52mm will I get more horsepower or will I get less power? I got both answers when I asked couple people. What I'm looking at is http://www.summitracing.com/parts/SUM-227701/ if I do get a throttle bodie or a BBK? Any recommendation will be great and thanks for your time. :)
 

·
Registered
Joined
·
8,978 Posts
You have intake, headers/exhaust so the 52mm is something that combined with those mods will help. You will see more of a advantage of it with a cam and heads modification.

you will need to have the PCM adjusted for the 52mm.
 

·
Registered
Joined
·
2,742 Posts
CFM.

265ci.

Runs WAY under the index in J/FIA stock.

Stock heads. Stock throttle body. Stock intake. Stock shortblock, but blueprinted.
 

·
Registered
Joined
·
5,568 Posts
CFM.

265ci.

Runs WAY under the index in J/FIA stock.

Stock heads. Stock throttle body. Stock intake. Stock shortblock, but blueprinted.
That doesn't mean he wouldn't run quicker with a larger throttle body. Plus, there is quite a difference between 265cid and 350cid.
 

·
Registered
Joined
·
2,006 Posts
With the 52mm you will get better throttle response. You will gain some in the 1/4 mile -- that has been shown by several people. Don't do an aftermarket throttle body for a 52mm. Check ebay for mjblum, he rebores and rebuilds the stock throttle body to 52mm for about $170. He also will take back your old throttle body for a $45 refund. Several forum members have used his throttle bodys and all of them have been very satisfied with the results.

As mentioned, you definitely need programming for the larger throttle body.
 

·
Premium Member
Joined
·
3,564 Posts
It would be last on the list for a mod for a bolt on car. You'll see little or no gain with minor mods. Spend the money on a set of 1.6 roller rockers and you'll see a noticeable improvement for a little more money spent.
 

·
Registered
Joined
·
2,234 Posts
i have a full bolt-on car and saw gains with a 52mm TB. you can see from my sig that it picked up but there is even more to the story

14.174/94.07 motor stock TB ----- killer air with low D/A
14.173/94.49 motor 52mm TB ----- 90*/90% humidity

this spring with not as good air as the first pass above

14.056/95.32
14.069/95.71


IT WORKS IN PRACTICE BUT WILL IT WORK IN THEORY
 

·
Registered
Joined
·
2,742 Posts
That doesn't mean he wouldn't run quicker with a larger throttle body. Plus, there is quite a difference between 265cid and 350cid.

That wasn't really the point I was trying to make.

This is:

It would be last on the list for a mod for a bolt on car. You'll see little or no gain with minor mods. Spend the money on a set of 1.6 roller rockers and you'll see a noticeable improvement for a little more money spent.
Why wouldn't you wait to spend money on something like a throttle body until the rest of your engine mods support it?

1) Dave Campolito, Salem, Ohio, '96 Caprice, R/SA, 12.776 seconds, -1.574 (under index)


(R/SA has a factored weight ratio of 18.00-18.99 lbs per factored horsepower. This puts that car at 207hp on 18.96lbs. So it weighs 3925 lbs.

From my cheesy calculator:
Your HP is 372.52 computed from your vehicle weight of 3925 pounds and ET of 12.77 seconds.

1 9569 J/FIA Corbitt Marshburn, Clinton NC, '94 Caprice 12.905 14.35 -1.445
A lot of guys are hard pressed to get a car into the 12's on the motor only, let alone with a very limited selection of bolt-ons.

Just sayin....
 

·
Premium Member
Joined
·
3,564 Posts
That wasn't really the point I was trying to make.

This is:



Why wouldn't you wait to spend money on something like a throttle body until the rest of your engine mods support it?



(R/SA has a factored weight ratio of 18.00-18.99 lbs per factored horsepower. This puts that car at 207hp on 18.96lbs. So it weighs 3925 lbs.

From my cheesy calculator:
Your HP is 372.52 computed from your vehicle weight of 3925 pounds and ET of 12.77 seconds.

A lot of guys are hard pressed to get a car into the 12's on the motor only, let alone with a very limited selection of bolt-ons.

Just sayin....
Been deep in the 12's with a bolt on car. A [email protected] so I am speaking from experience and not what you read on the board. The TB on a basically stock bolt on car will give you no gains. I guarantee it.

I couldn't tell if you were in agreement or not with your reply.
 

·
Registered
Joined
·
2,742 Posts
Sorry, I didn't make it real clear.

Was trying to say you and I were both making the same point...TB should be the LAST purchase, it really isn't going to cause any velvet robes to open, or the skies to part by going with an aftermarket part, over the stock one.

Sorry 'bout the fuzzy reply.
 

·
Registered
Joined
·
2,234 Posts
i agree the TB should be the last purchase but don't agree it will not help a stock motor. i ran 94.07mph in 200' D/A (or might have been -200). since adding the 52mm i have only ran that low one time since and havn't ran in that good air since. i ran 94.13 and 94.05 in july this year with a 2300' day. i've run 95mph or more every other trip and the D/A hasn't been under 1000' any time this year. i ran the 95.71 at 13-1500' in april. i expect over 96 easily this fall when the air is good again.
 

·
Registered
Joined
·
2,006 Posts
If you need programming anyway, then the rebored stocker from Matt Blum is one of the cheapest mods (only $125 after core exchange). Then you have it to support future mods as well. It's also a very easy mod, you don't need to get into the motor or bring it to a shop for installation. Besides, who knows how much longer people like Blum will be putting time into supporting our platform? Once it becomes scarce, prices are going to jump a lot. Just consider how much the aftermarket 52mm throttle bodys cost now, and how much less reliable out of the box they are then a rebored stocker. One thing for sure, the 52MM won't hurt performance on a stock motor.
 

·
Registered
Joined
·
501 Posts
With the 52mm you will get better throttle response. You will gain some in the 1/4 mile -- that has been shown by several people. Don't do an aftermarket throttle body for a 52mm. Check ebay for mjblum, he rebores and rebuilds the stock throttle body to 52mm for about $170. He also will take back your old throttle body for a $45 refund. Several forum members have used his throttle bodys and all of them have been very satisfied with the results.

As mentioned, you definitely need programming for the larger throttle body.
that seller on ebay said that since the intake manifold is also 52mm you dont need to reprogram the pcm, im not sure if thats true or not but he makes them so he may be right,
 

·
Registered
Joined
·
5,568 Posts
the reason for reprogramming has nothing to do with the holes in the intake. It has more to do with transmission line pressures. Get it reprogrammed or risk having your transmission fail.
 

·
Registered
Joined
·
2,006 Posts
that seller on ebay said that since the intake manifold is also 52mm you dont need to reprogram the pcm, im not sure if thats true or not but he makes them so he may be right,
You are looking at xtreme-fi then. Different seller than Matt Blum. Matt Blum does not make the claim that you do not need reprogramming. I have no idea how well rebuilt the xtreme-fi seller's throttle bodys are, but they are more expensive. Stick with a known and respected vendor. Look for seller mjblum.
 

·
Registered
Joined
·
2,742 Posts
 

·
Registered
Joined
·
5,568 Posts
That wasn't really the point I was trying to make.

This is:

Why wouldn't you wait to spend money on something like a throttle body until the rest of your engine mods support it?



(R/SA has a factored weight ratio of 18.00-18.99 lbs per factored horsepower. This puts that car at 207hp on 18.96lbs. So it weighs 3925 lbs.

From my cheesy calculator:
Your HP is 372.52 computed from your vehicle weight of 3925 pounds and ET of 12.77 seconds.

A lot of guys are hard pressed to get a car into the 12's on the motor only, let alone with a very limited selection of bolt-ons.

Just sayin....
Sorry I skipped over this before. My car has been within 2 tenths of that 96 Caprice, also with bolt-ons, and stock valvesprings, stock throttle body, stock intake manifold, stock pushrods, stock rockers, etc. My car was also ~200 pounds heavier at the time. Somebody told me that my car would not have been legal to run those classes, but I'm still not sure why? Maybe because the RAISS intake or headers? I know that there was a lot more that I could have done at that point to make it run better, but it was still my daily driver at the time :D

I'm not disagreeing with you though. There are a bunch of other mods that should come before a bigger throttle body.
I'm not agreeing with you either. I think there is potential power in the throttle body, even in a stock engine. The benefits might not be enough to outweigh the costs though.
 

·
Registered
Joined
·
2,742 Posts
The benefits might not be enough to outweigh the costs though.
Kinda what I'm driving at here.

And keep in mind, both Caprices I've quoted in this thread are L99 cars.

All I'm getting at - the stock throttle body will support a lot more HP and bolt ons before you absolutely NEED an aftermarket one.

There's better places to get 'bang for your buck' in my opinion.
 

·
Registered
Joined
·
2,742 Posts
but I'm still not sure why? Maybe because the RAISS intake or headers?
Depends on the tech guy you get on the air filter, but that's likely where you'd get flagged.

Stock is a pretty specific class.

You can get the IHRA rulebook online (it's got a little more leeway on the rules than the NHRA one.)
 
1 - 20 of 39 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top