I was wondering if anyone here could give me some good advice for giving my 92 4.9L Seville some more performance. I currently have the TPS enhancer, flowmaster exhaust (which is a little loud on the freeway) K&N air filter, bosch platinum plugs and O2 sensors, and a fastchip. i was thinking about porting the throttle body and exhaust manifolds to give me smoother airflow. what other little things can i do to give me more performance without messing up the computer?

You could use a intake manifold off a Cadillac Allante for +20 hp.

what year models should i look for? and is it an exact bolt on replacement?
EDIT: im also seeing upper and lower intake manifolds, what do i need?

thanks for the info

nick

i doubt 20+... IMO. good luck finding that part tho.

USE SEARCH and search for "4.9 external upgrades". you'll find all you want to know there.

wow there was alot of info on that thread, i liked it alot. does anyone know if there is a bigger throttle body availible for the 92 seville? like aftermarket or something? would someone like to post how to make that cool intake that was on that other thread or where to by something like that, ive looked and cant seem to find anything.

thanks

nick

i doubt 20+... IMO. good luck finding that part tho.

USE SEARCH and search for "4.9 external upgrades". you'll find all you want to know there.

The reason I say +20 HP is because the Allante 4.5 had 20 more horsepower than the other Cadillacs with the 4.5. I happen to own a Allante and a Eldorado with the 4.5 and the Allante definitely has way more power.

i hate to tell you this, but for anymore power, you are going to need to go internal. you will get a lot of power by having the heads/intake ported and polished with the runners matched. you may also want to look into having a cam regrind done too. also worth looking into is having the heads decked and the sleeves bored too. thing is, you will need some mucho dinero $$$ for that kind of work, which, from my research, will cost around 12-1500 dollars. you will also have to get another chip burned (custom) for all of that, as well as a fuel injector upgrade to match the cam change. but from what i understand, you WILL get a serious increase in power from that kind of work (85-100+ hp). good luck on the project, and hope to see that caddy kickin ass :lildevil: which im sure it does already.

The reason I say +20 HP is because the Allante 4.5 had 20 more horsepower than the other Cadillacs with the 4.5. I happen to own a Allante and a Eldorado with the 4.5 and the Allante definitely has way more power.

yeh, i suppose that'd be right then! you can machine/dremel you intake to accept an LT1 TB. Let's see... where'd I see that? try fiero.nl and go to pennocks forums. it's somewheres around there. also, with a regrind, you can go much taller without having to get some new springs (pretty tricky to find some that'll work from what i hear) good luck, and hope to see some mods soon!

http://www.fieroaddiction.com

just look for the 4.9 liter section on this site.
this guy has done some intake work on his car, and from the way it looks, it seems that his 4.9 can kick ass. and what he has done would be cheaper by far than trying to locate an allante manifold (i tried that once!).

wow i dont think i want to go that far by getting the heads decked etc, i dont want to have to mess with the computer, that just adds more problems down the road, i dont want to turn her into a dragster. i was just thinking port and polishing the throttle body, intake and exhaust manifolds etc. one thing i am intested in is possible cold air induction, not where the air cone is sitting right on top of the engine sucking up radiator heat, im talking has anyone actually routed it possibly into the fender scooping up fresh air, or if that cant be done, i found some airbox mods for the N* but havent found any yet for the 4.9L not sure just drilling holes in it would work like on my old TPS camaro. right now im running the fastchip and only running mid grade fuel, and it doesnt knock at all even on a hard accel, so i dont think i will be able to get away with advancing the timing, and not running premium fuel, and with the gas price today over $2 a gallon for premium i think ill stick with mid grade since it seems to work. also due to posts that ive read about on here about exhaust i think im going to take off my flowmasters, and put on elderbrock, from what ive read there is almost no interstate noise, which with the flowmasters there is always a loud roar in the car, the RPMs are too high at 75 or 80, hopefully the new muffler will fix that, im not putting bigger tires or anything, i like the stock size. thanks for all the posts thus far, this place is packed with information, im still reading up atm, but please fill free to post with more info, i need all the help i can get. ;)
EDIT:
I just wanted to add that i have had the accel super coil on there before and it added too much spark, my car started acting real funny, would start to backfire going up hills etc, real lose of power after about 4 months, and come to find out the little tip that rides on the rotor in the distributor cab had been made FLAT by all the spark, when its suppose to be nice and round, so i removed it to fix the problem, which in turn i think killed my flowmasters, which is why i want to change, i get a real raspy sound out of it now doesnt sound like my camaro with flowmasters did thats for sure. i had tried putting MSD ignition on there and saw no gain at all, i called MSD tech support and told them about it and they said that the ignition on the cadillac is already as high tuned as possible and i wasnt going to see any gain until i did some very heavy modding and the regular ignition couldnt keep up, so once again a waste of money. i also went by bruce's site and put a 180 degree temp stat in there and i start over heating, from what my mechanic and i could guess, it was opening up too soon and not giving the radiator enough of a chance to cool the coolant before it released it back into the system and there for over heating the engine, once i went back to a 195 all was good. before i found this forum all i had to go by was bruce's site, which is very well written but i found a ton more info on here which is awesome. my car has over 200K miles on it and its the most solid car i have ever driven, had to replace the AC compressor a couple times and one water pump but that is normal. the only annoyance i have now is that i have a clank coming from the rear of the engine next to the firewall when i start it in the morning, i had read about it on here from another thread and tried the things that were said on there and didnt fix the problem, sounds like tranny but it drives excellent. but in any case you can just feel that the car has alot of potental and im excited that i found a forum that can help me get that potental out of my car. thanks for all your input.

nick

gettting "too much spark" or whatever that means wouldn't make your muffler go out. Something just probably came loose in there. How did you deal with the cleanace issue with your Accel Super Coil. I didn't think they'd fit with the stock intake? I couldn't fit one with mine so I had to ghetto fab something.... And, no MSD or Accel or whatever ignition won't give you any performance. You're wasting your money if that's what you're after. You're correct about the cooler tstat. That rad is only big enough to cool your engine. you can't just put in a cooler stat and the engine will run cooler. I don't care if you stick in a 160, it'll still run 190s. Also, the muffler won't make you run "too many RPMs" on the freeway. I'm sure that's not what you meant. I had dynomax and it was loud. i went to magnaflow and it's loud. if you want quiet, go with stock! later!

maybe i wasnt clear, let me fix that now, the "getting too much spark" didnt blow my muffler, but it did cause too much spark in the distributor and wore down the little tip that sits on the rotor to where it was flat causing all kinds of havic on my engine including all kinds of back fires, the back fires are what got my muffler, my cat is empty. the accel super coil replaces the stock coil on the distributor cap, i didnt have any clearance issues at all. :hmm: and i thought the fast chip needed the tstat which is why i got it, but it just messed things up. and again i know the muffler wont give me too many or high rpms on the interstate, i was saying that with the rear end ( or lack there of) being built into the tranny, the RPMs are high at 75 or 80mph period, the flowmaster just makes it very loud at interstate speeds due to the rpms. and i dont want to go stock i want a quiet high flow muffler, if there is such a thing, ive been reading up on the forum and its still not clear to me if there is such a thing or not, some people say there are while others say the opposite. who knows, but i hope that clears things up a little.

nick

and i dont want to go stock i want a quiet high flow muffler, if there is such a thing, ive been reading up on the forum and its still not clear to me if there is such a thing or not, some people say there are while others say the opposite. who knows, but i hope that clears things up a little.

nick

I installed a Flowmaster Deltaflow Model 50 on my 1988 eldorado and it's quiet. They are the most quiet model that Flowmaster produces. I didn't notice any difference in sound level inside. Outside, there is a definite Flowmaster sound only when you really get on it. Do you still have your CAT? If not, you might think about installing your Flowmaster where the CAT was.

Do you still have your CAT? If not, you might think about installing your Flowmaster where the CAT was.

or a simple glasspack like mine...it's cheaper. don't just replace with a straight pipe... it's super loud in the cab then.

the cat is hollow, not a straight pipe, someone gutted it before i bought it (didnt find out until later). Edahall are you saying put a flowmaster CAT in its place? if they make one? LacSeville what is a glasspack? i thought that was something imports used for exhaust kinda like a cherry bomb? sorry for my ignorance on this subject. Ill look into the quieter flowmaster you spoke of thanks, btw, how much did it run you?

thanks

nick

the MSD ignition will work if you can throw more fuel at the engine,which i have. but because of the camshaft, there is little room for improvement. i did notice a little better power from my MSD, but it was in the power rpm range, but by no means a fix for more power. like i stated before, you will need more fuel (larger injectors, or a pressure regulator) to make the most of it.

the cat is hollow, not a straight pipe, someone gutted it before i bought it (didnt find out until later). Edahall are you saying put a flowmaster CAT in its place? if they make one? LacSeville what is a glasspack? i thought that was something imports used for exhaust kinda like a cherry bomb? sorry for my ignorance on this subject. Ill look into the quieter flowmaster you spoke of thanks, btw, how much did it run you?

thanks

nick

Replace the gutted CAT with some type of muffler (glass pack or flowmaster) to reduce the drone. If you want to be legal, then put on a CAT which also reduces noise levels.

A Glasspack is a cherry bomb. They sound really nice because of they muffle high frequency noise well but not the low frequency. This is what gives it that deep rumble sound. Low frequency also transmits easily into the cabin so if you want it to be quiet inside, this is not the way to go. I've also heard that they are more restrictive but maybe this is only true on the cheap ones that neck down inside.

I bought my Flowmaster 50 series deltaflow on ebay for $25 + $10 shipping. New, they are around $100 from Summit and slightly more if you want Stainless Steel.

you wouldnt happen to have a specific model # would you on the 50 series? do they make one for the cadillac or do we have to try to find a camaro equivelant?

nick

I was thinking about putting dual magnaflows on my car in 2 weeks. Have any of you guys with those flowmasters or dual anything noticed an increase in hp? I'm having the pipe out the cat expanded to a 3" diameter.

I was thinking about putting dual magnaflows on my car in 2 weeks. Have any of you guys with those flowmasters or dual anything noticed an increase in hp? I'm having the pipe out the cat expanded to a 3" diameter.
it will help a little, as i certainly noticed a difference. but i wouldnt expect huge gains from just that.

exhaust will probably be the single best upgrade you can make on your 4.9. don't bother with dual mufflers... if your car only has 1 muffler now, just replace it with a magna or flow. two mufflers won't help any more than 1 good flowing one.

maybe i wasnt clear, let me fix that now, the "getting too much spark" didnt blow my muffler, but it did cause too much spark in the distributor and wore down the little tip that sits on the rotor to where it was flat causing all kinds of havic on my engine including all kinds of back fires, the back fires are what got my muffler, my cat is empty. the accel super coil replaces the stock coil on the distributor cap, i didnt have any clearance issues at all. :hmm: and i thought the fast chip needed the tstat which is why i got it, but it just messed things up. and again i know the muffler wont give me too many or high rpms on the interstate, i was saying that with the rear end ( or lack there of) being built into the tranny, the RPMs are high at 75 or 80mph period, the flowmaster just makes it very loud at interstate speeds due to the rpms. and i dont want to go stock i want a quiet high flow muffler, if there is such a thing, ive been reading up on the forum and its still not clear to me if there is such a thing or not, some people say there are while others say the opposite. who knows, but i hope that clears things up a little.

nick


all right nick if you want a good sounding muffler,get the edelbrock rpm series #5509 i have that on my caddy and it's loud but on the highway it''s not droning but you still know that you have a nice exhuast if you want i'll post a sound of my car doing 70-75 and take it from there,but if you want to hear the exhaust check out my cardomain site i got here http://www.cardomain.com/memberpage/472581/6 also if you want to know about my intake on page 7 just e-mail me and i'll break it all down for you.