TraviZ

iTrader: (2)

check it out, summit part # 227707

just saw it in the new magazine under new products.

looks good in the pic, and 260 bucks makes it the cheapest twin 58mm yet..

part # 227705 for thw twin 52mm

Matthew91-Z28

wow...wish they had a picture of it.

subliminal

iTrader: (1)

Awesome I will be buying one

onfir3

Cool, post a picture when you get it

89TPI350

Yeah I was also looking at that throttle body, and it seems like a great deal for a 58mm. I would like to see some pics too

CamarosRUS

Thats hilarious...I saw that tonight and was gonna make a post about it!
There is a small pic on the new products page in the catalog. Looks plain but good.

TraviZ

iTrader: (2)

ive had this ol' holley plate from an lt1 throttle body just sitting around, should fit good on this new summit peice i hope!

rwdtech

would the 52mm or 58mm throttle body give me a noticeable increase in power on a 305 with headers? is there something else i could put on that will give me more hp/ dollar besides cam or heads?

just wondering

irocyourpants

iTrader: (2)

if its just a lightly modded 305 I wouldnt go any bigger than the 52

58 is overkill in most cases

TraviZ

iTrader: (2)

go 58, never get enough air, and if you are, bigger injectors (Y)

Jade Grey

iTrader: (1)

There's a bigger picture listed for the 52mm LT1 version. I inserted it below. The TPI version should look very similar.



Now someone needs to buy one and actually review it. It looks like the 58mm TPI version will be shipping by the 25th.

TraviZ

iTrader: (2)

aye that thing is very coola nd looks just like the tpi version in the magazine.

Fast92RS

iTrader: (2)

The only thing is they list the throttle body as one part number for 85 - 92. But there were two throttles bodys made these years 85 - 88 and 89 - 92. Which one do you get? The throttle cable hook ups were different in these years. 85 - 88 can fit on 89 - 92 but not vise versa.

lonsal

iTrader: (2)

From the product description on Summitts web site: "The die-cast aluminum throttle bodies feature duplicate throttle linkages that are easily changed by removing a nut, so you can use them on different model years."

Lon

CamarosRUS

Sweet idea.

As far as using the bigger throttle body on a 305...it's not needed. Id like to see some dyno numbers because this debate has gone on forever and no one has gotten a solid answer. IMO the 52 and 58mm tb's won't do anything for a 305, you would be better off spending the money elsewhere. But, if you are going to get one anyway defenitly get the 58.
I had my 58mm on my 305 before the 383 and didn't notice any difference at all. This was also with headers and a full 3" exhaust without cats.

Fast92RS

iTrader: (2)

Thanks I didnt read that part. Im up in the air with it. I want the 52mm version but the summit one is about $50 less than the BBK version. Not that much when your spending almost $300. If anyone gets the summit one please post what you think.

freestylzz

Don't forget to get your air foil aswell

LAFireboyd

iTrader: (3)

But that's not because it was a 305. A 305 has the potential to make over 400 normally-aspirated hp, though that would be about its limit. But that's about all most people strive for anyway when they build their larger engines that have greater potential. A 305 can interchange most 'go-fast' parts with larger engines and produce excellent results. So most likely, the reason you didn't notice any difference wasn't because of your engine's size, but because of the stock breathing capabilities of both, the intake and the heads, not to mention the capabilities of the cam.

You improved the way your engine exhaled, but if you didn't improve its ability to inhale(and I'm assuming you didn't because you didn't mention it), then even though you made it possible for more air to enter through the larger 58mm TB, the rest of the stock parts weren't capable of providing and using more air before and after the TB, so more air wasn't actually entering--at least, not enough more to let you feel a difference. And without making it possible for the engine to inhale more air(or at least 'act' like it's inhaling more with the 'mass' factor), then not enough 'more' air will be passing through the TB, no matter how large the TB is. So yeah, then you're right when you say that a 58mm TB wouldn't be needed on a 305. But with those same limitations, it wouldn't be needed for a 350(or larger) either, which would probably be held back a little more by the intake than a 305 is, though not by much more.

So on a dyno, with all the appropriate improvements before and after the TB, you should see proof that a 58mm TB can be effective on a 305, too. But because most people abandon the 305 in favor of a larger engine, we rarely see such changes made or tested, unfortunately. But hopefully, by the end of the summer, I'll have evidence of such changes.

I happen to love my 305! Yeah, if the 5-speed had been offered on the 350, I'd have ordered a 350. But it wasn't, and I have never regretted having my 305. It's been an amazing engine for me. So to touch on the topic at hand(finally, lol), that throttle body with its price looks like it could be the one for my project--a built 305, for which I'm getting parts together right now. And it looks like the stock "Tuned Port Injection" cover will fit on this TB also. I like that.
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Looks built-in already, though the edges could use a little softening.

TPI

Yea there should'nt be too much diffrent from the TPI/LTI
throttle bodies from summit shown in the pic, So I assume
that the TPI TB will be identical.

And the interchangeable linkage idea is brilliant !!

Ive been looking for a cheaper alternative to a 58mm TB
and I believe Traviz just found it for me :P

Im impressed with the overall product, but someone needs to
purchase it and review it just like Jade Grey said

subliminal

iTrader: (1)

Ive heard if you put a 58mm TB on a engine thats not modified much it can actually hurt performance

CamarosRUS

That has to do with velocity and is, as well, always up for debate.

Yes, a blown or highly modified 305 putting down serious numbers will benefit from a bigger TB but not your average and slightly modified 305's.

Jim85IROC

iTrader: (2)

I'm not sure it'll hurt things, but it's not going to help anything either. Your plenum will act as a "baffle" between the throttle body and the intake runners & combustion chambers, so the whole "velocity vs. flow" debate pretty much washes out.

When I started having problems, I pulled my TPIS throttle body off my mildy modded Corvette (mid 13 second car) and replaced it with a stock one. My WOT performance was exactly the same, but the car "felt" slower because you're letting in less air for a given throttle position. This condition is what fools people into thinking they've gained performance, when in fact, they just managed to get to a certain level of performance with less throttle input.