Hey group. i have a 383 with a fair amount of go fast parts and hooker sidepipes. i thought i would uncork them to see what i might be loosing with the baffles. boy was i suprised to see how much i was leaving on the table with them baffled. its like a new car. i have a couple of questions.

1.anybody know good 4 " insets to put in the tubes. open sidepipes sounds way way cool but i think dallas's finest will catch up with me. i know that spiral tubes makes some but 400 for inserts seems kinda pricey...any suggestions?

2. why would my car seem quicker when the car is first(10 minutes) warming up. do i need to bump up my jets? there seems to be more seat of the pants speed before the car reaches its normal operating temp which is around 170-180 degrees.

please note these are all seat of the pants tests. but the sidepipes thing is amazing i am getting 275's tires spinning through second gear and that was not there before.

yee haw. plus is sounds very cool...maybe too cool. thanks for ideas tommy

You car is more powerful cold,
at the track if you cool off between rounds
to a consistant temp maybe 120 at the stagging lanes, then run a 7.50 then if you dont cool it just get back in line you might run a 7.60!

Do a look up for "JCL Baffles", they make an insert that breathes alot better then the stocker Hooker Baffles. Also, go over to www.corvetteforum.com (http://www.corvetteforum.com) into the C3 Discussion secion if you want some more opinions, considering the amount of guys over there running them.

Are you currently using spiral turbo baffles or the hooker stuff?

[This message has been edited by WildBillyT (edited December 14, 2004).]

i had some inserts i got on ebay. they originally had packing around. got rid of that in the first few days of car running. then i took the rest of the baffle out. with regard to the jcl baffles is that this company

http://www.spiralturbobaffles.com/ordering.html

that is place that is around 350.00 for the pair.

currently they are open and staying that way until i find a non power robbing solution.

big block thanks for the heads up. i started looking around after the post and found that place. now i am reading there posts.

any other ideas. thanks

The real power solution is to ditch the side pipes and bring your exhaust into the 21st century. We were evaluating exhaust systems for a road racing Vette and found that the Hooker sidepipes and mufflers were costing us nearly 100 horses. A set of Stahl underchassis headers, an x-pipe and turbo mufflers was the most powerful reasonably quiet setup.

thats what i am finding with the inserts in and then out. huge power gain with them out. however i am kinda white trashy and the sidepipes are staying. they found a 98 hp gain from hooker inserts to the spiral baffles. what inserts where in the sidepipes you tested? did you test open? thanks onovakind

here is from spirals web page.

Bill VanOrman
Carmel, NY
Testing done by: Romar Enterprises, Walden,NY
Car: 1969 Corvette Engine: GM 502BB, Iron rectangular port heads, hydraulic cam/220 duration@.050 and .500 lift, 8.75 to 1 compression, low rise LS6 intake, holley 750 double pumper carb, and Hooker Sidepipe Headers. Tests are RWHP figures 1/5/2002
Base: Mufflers, HH reverse flows. 246.7 HP/388.9 torque.
2nd pull: Mufflers/ baffles, Spiral Turbo Baffles (4"). 338.5HP/408.8 torque. An increase of 92HP and 20Lbs. Ft. of torque.
3rd test: Sidepipes, no mufflers or baffles. Wide open tubes. 342.4HP/445.1 torque. Thats a high bolt on increase.
This particular engine needs more cam and head work, suggested by Romar, Ent. after testing was complete. Romar felt with these modifications, getting power in the 550+ range would not be difficult.


[This message has been edited by 67lemanster (edited December 14, 2004).]

We used a 331" small block with the standard Hooker sidemounts and muffler inserts. I don't recall the numbers off the top of my head, but the car made 380 rwhp @ 6000 rpm with the Stahls, and less than 300 with the Hookers.

We also had a 496" Vette with sidepipes on the dyno that struggled to make 325 rwhp, we felt it should have done much better. My 331" 2-bbl road racer trumped that with 365 rwhp.

<font face="Arial,Verdana" size="2">Originally posted by 67lemanster:
is that this company </font>

yeah, I believe that's the place, if you mention the corvette forum you might get a discount (I think they are a supporting vendor). If they ask who you are - use the ID of "70PurpleLS7".. http://www.nastyz28.com/ubb/smile.gif

thanks all. i was hoping for a cheaper route but after reading corvette site it seems thats the deal. spiral turbos it is. thanks again. blownbigblock thanks for the use of the id. hoping maybe for some special X-Mas deal.

Hmmmm, if this is so, then I wonder what a Viper would gain?? Or is it not a true side pipes setup?

you could keep some of that seat of the pants feel if you do some things to keep stuff cool.

my z28 would slow between back to back rounds at the track and to make my car more consistant( and faster) i insulated all fuel lines under the hood from the time it enters from the firewall to the carb,installed an oil splash shield under the intake, i allready had the factory cold air induction to the carb on the z28.and i rerouted my fuel line away from the block. and i blocked off the heat cross over with some plates cut from a pop can.

just these few changes reduced some of my intake heat readings 50 degrees and my carb bowls was about 25 degrees cooler.

i used a temp gun before and after with a fully warmed engine.

this showed in my e.t.s and mph to make my car run back to back numbers with less cool down time.

you could use a carb shield too. i didnt have room for this mod or a carb spacer. this should help alittle more.

i allready run a 160 thermostate.

i also changed my oil to full synthetic oil.

and i changed from a flex fan to a stock clutch fan.

all these mods increase my mph from 105 to 107 mph and made it more consistant like i was saying at the track between rounds.

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1980 z28 3900lbs daily driver,414ci bbc,13.505 @107.19 mph w/2.15 60ft. 2.73 gears in street trim.

1981 camaro "the race car" as the kids say. 454 .060 over 13 to 1 comp.roller cam,nitrous, 4500 stall and 4.56 gears...severe traction issues,10.80's to low 11's @ 126mph....under recontruction on chassis

1986 ford pick-up "the tow rig" runs a slow 18.00 flat at 75 mph in 1st and second gear only.

<font face="Arial,Verdana" size="2">Originally posted by 1978LT:
Hmmmm, if this is so, then I wonder what a Viper would gain?? Or is it not a true side pipes setup?</font>


he is working on a viper system and a c5&6 system. the vette susytem repalaces the rear muffler with his spiral turbos. kinda neet. plus you can tune his to sound there is a cap on the end that you can drill a hole to for increasing sound. wont have a lot of effect on perfomance though. but i like stuff loud...just not open header loud.

ddeenis i will fix what i can with your suggestions. i already have a cowl hood to help with heat but will wrap the fuel lines, i run an air gap intake, synthetic oil. thanks for the rest of the suggestions. tommy

I don't know if it is as interesting as it is obvious when you look at that horrendous design of the Hooker insert. If I remember correctly the inlet and outlet is 1.5". Just a disaster of a design. In addition the primary tube length of those sidepipes are very long, too long given typical camshaft profiles off the shelf. We spent a lot of time modeling camshaft profiles when we did a vette motor that the customer was using those pipes on. Onovakind is right on that for overall performance they are not the best overall design, although they do look cool all powdercoated.

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70 SS 454 CI Dynoed 684 HP, 702 TQ All Aluminium Fuel Injected Small Block , plus 200 - 500 HP NX nitrous system.

Hooker lists the primary tube length for the 2237 Camaro sidemounts as 1-7/8" x 50". The primaries are too large and long, the 4" collector is too large for the primaries, and they screw up the physics of the scavenging wave by stuffing a muffler up into the collector.

coolness factor more important than speed. i have a fast car too. but thanks for the help.

I have always wanted to make a set of mufflers that use "Static Mixer" blade design technology inserts b/c I figure that they would flow great and be quiet to boot...

pdq67