has anyone ever installed a throttle body bypass? if so do they help do they work and how diffecult is it to install. they are on ebay for sale that is why I asked . they advertise 8 hp gain???????:auto: :chevy

 

I hope they work, I just did mine for $6. I wouldn't expect 8hp, maybe 3hp. But for six bucks, why not. Anyways, only do it if you don't drive your car in the winter. The purpose of the coolant is to heat the TB so that the humidity in the cold air coming in doesn't freeze the valves open. It actually happened to my father-in-law in one of his cars before they started running coolant through there. But you can just go to any autoparts store and buy a piece of hose (mine was 5/8") and two hose barbs with clamps. run the hose under the TB, but becareful not to crimp the line.

 

I'm going to go out on a limb and say there will be little to no gain. It looks more like a "feel good" mod than anything else.

I put it on my 90 because I was tired of messing around with the hoses when removing/installing the TB.

BTW I got my bypass from my local Ace Hardware Speed Shop -> 2 hose clamps and a hose splice for $1.56.

Dale

 

It isn't going to give you a neck snapping feel, but every little bit helps.

 

Don't believe everything you read. I don't think you'll see anywhere near 8 HP from this mod. I did it on my 91, but it was one of several of the "free" mods done at that time so any gain from that particular mod was not noticed. Also, there is no need to buy the kit. Search for "Throttle Body Bypass". There is a wealth of info on the procedure.

 

HERES THE BYEPASS WITH JUST A RE-ROUTE of the hoses
http://www.thirdgen.org/newdesign/te...ntbypass.shtml



HERES WHAT I DID ON MY STEALTHRAM TO CLEAN UP THE ENGINE AND MAKE MORE CLEARANCE FOR THE WATER NECK, (this is the heater manifold under/side of your throttle body for those of you that don,t know) this requires about 5 minutes work with the band saw and belt sander, and any machine shop can do it if you dont have the tools handy in 5 minutes if you show them the pictures, and YES IT REALLY HELPS CLEAN UP THE ENGINE COMPARTMENT AND GAINS LOTS OF WATER NECK CLEARANCE


and yes because it lowers the average incoming air temps the engine sees it allows a denser cooler air that allows slightly more fuel to be efficiently burnt to produce more hp, the amount is small but its there.(5-7 hp) according to what one of my friends saw after the change on his dyno run (NO I DON,T HAVE THE DYNO SHEET HANDY) AND YES ALOT DEPENDS ON THE OUTSIDE AIR TEMP COMPARED TO THE UNDER THE HOOD TEMPS INVOLVED, but I have no reason to doubt his word , and I find no down side after doing the mod to my vette, and yes it does seem to help slightly. and yes it will take your car about 2 more minutes to heat up at idle as far as the plenum temp sensor is concerned , but it runs great with zero problems, and yes your correct if you live where the temps get to below ZERO all the time it may not work for you!








[Modified by grumpyvette, 3:29 PM 3/19/2003]

 

I don't know how much it helps, but it certainly can't hurt.....especially living in Fla. where its not very likely that your throttle body blades will freeze over (the purpose of the coolant line through the TB). I did it in conjunction with a few small mods and noticed a modest gain. I simply bought a length of heater hose and ran it from the firewall directly to my intake manifold thus eliminating the throttle body from the route. This gives a very clean look without any splices in the line. I can't recall what the hose cost, but it couldn't have been more tha $5. Afterwards you will notice that your TB feels much cooler to the touch when the cars running and thats gotta be a good thing. :yesnod:

 

:iagree: I don't know what I gained but the TB and Plenum feels much cooler to the touch.

 

There are two benefits:
1) the TB and so plenum runs noticibly cooler in hot weather
2) servicing the TB is much simpler (no coolant drainage required)

Go to Auto Zone, buy two vacuum nipples, two hose clamps, a plastic splice, a U-shaped section of heater hose.

Cut the U shape to bring the hose out under the TPS and down behind the A/C compressor. Cut the heater hose behind the A/C compressor and splice into the bypass hose and install the short end of the U onto the front of the engine. Press the two vacuum nipples over the coolant ports on the TB and you are done.

Don't worry about winter driving; I've been driving my Vette in near zero deg F weather this winter with no problems. My IROC has had this mod for over 5yrs with no problems either.

 

It probably only gives a couple hp at best, but in unison with the other 'free' stuff it helps.

It cant hurt anyway, not unless you live in Alaska.

 

Ok, feeling stupid here. Most of you mentioned this seems like something we should do "in conjuction with other free mods". What are some other FREE mods? I am one of those who fell for the by pass kit from Eckler's.
:mad

Needless to say, you all will have a nice round of cold ones on the money you didn't spend buying the "kit".

:cheers:

I appreciate any input about other free mods. :thumbs:

 

free mod's I can think off, aside from t.b. bypass include cutting open the air filter lid.

 

Its a common misconconception that this happen when it is freezing out (32 or lower.) It happens at above freezing usually about 40 degree with high humidity. It does rarely happen, but I have only met 1 person that claims to have had icing happen in a dry fuel injection. Anyways someone in FL on relatively cold winter night is more likely to have this happen than in aslaska where it is commonly below 0.

 

This is a site that i use for reference, it goes thru some Basic to major mods, then it lists the 1/4 mile time after each mod. http://vette.ohioracing.com/ :seeya

 

ok first nothings free! youll need to use your skills.time and at least some money, Ill list what Ive found that works, first DO A GOOD TUNE UP! http://www.thirdgen.org/newdesign/tech/tpimod2.shtml

(1)the throttle body bye-pass above,(dont forget the heater manifold MOD ...AFTER YOUVE DRIVEN THE CAR FOR AWHILE to make sure it has NO BAD EFFECTS IN YOUR OPINION!)

(2)air foils in the throttle body basically a waste of time and money but yes you can get 1-3 hp at 5000rpm

(3) cut the top of the air filter cover to allow more airflow (worth up to 10 hp at high rpms) and install a K&N style high flow filter (this also helps but costs some money)

(4) remove screens in the M.A.F. this is good for about 100cfm of flow increase and is a good mod but can cause your engine to idle rough untill the ECU "RE-LEARNS" the differance in improved air flow)

(5) swap to synthetic oil an easy 3-5 hp due to reduced friction

(6)install an (X) pipe in the exhaust results vary wildly but if you match this to a free flow exhaust and low restriction (CATS)or no-restriction (GUTTED CATS ) a 20-30hp gain is possiable at higher rpms

(7) kick up(ADVANCE your timing about 2 degrees) most cars respond well and it tends to allow the engine to rev, quicker


(8) porting your intake runners,plenum,base an easy 10-15 hp for a weekends work on the stock intake

(9) pocket port your cylinder heads/ reinstall with thinner head gasket a full weekends work and about $100 in gaskets but an easy 20 hp here if you know what your doing!

(10) install a better oil pan, by modifying the stock oil pan with an extendes sump and baffles lots of welding and measureong here but for several hours work and a scrap oil pan or scrap sheet metal,plus a few small hinges the stock pan can have the sunp extended forward and sideways enough that the 5 qt pan can handle 8 qts plus better control the oil (make all patterns from card board first and tape for welds untill you gett all measurements correct then cut the metal and weld the pan, mak your mistakes in cardboard first


[Modified by grumpyvette, 9:03 PM 3/19/2003]

 

My 89 used to run great when cold, and lose power when hot. With the B-P mod it seems to run the same as cold even when hot. I have had no problems of freezing in cold weather. Another GREAT mod for your car is to remove the frisbee. You will feel a SOTP difference since the engine will rev quicker.
:cheers:

 

sure you're not going to get a noticable difference, but hot air going into your throttle body sure isn't helping you. I did it in 15 minutes and I think it cost me .50 for a couple hose clamps.

 

Even though you are supposed to run premium fuel, my car runs great on mid-grade unless it is really hot outside. After the TB bypass, I can run on mid-grade with no ping even at full throttle at 90 plus degress outside. An added benefit maybe...

 

Do you realy think those mods. would add up to 85hp? I don't Know if it would even add up to 30 at the wheels.

 

When you remove the screens what do you mean by the ECM has to "RE LEARN" with the improved air flow :confused: