I just bought a 1998 Buick Riviera with the series II 3800. Anyone know of any computer upgrades available for it? (no DHP) I have tried registering at clubgp and had no luck....seems to be an extremely slow forum and I can't even register with the user name I want (somehow my real name got in there....embarrassing, I never put my real name next to anything that said "username"). Anyway the moderators won't return my e-mails and I have trouble navigating that site or making progress with it. I know I want to do the 3.4 inch pulley but other than that.....I'm not sure just what else I can do if anything. It seems nothing else is made for the Riviera. Someone from 3800 Performance said there is no DHP for the Riv ....I would think the one for the Regal GS would be the same but they say no. I wanted to do a high flow downpipe and FIPK but those aren't made for it either. I may go with a shift kit, cold stat, homemade FIPK, homemade downpipe (that sucks), and the 3.4 inch pulley. I guess there simply is no option for tuning....I wonder if there's a way I can get rid of the top speed limiter without a DHP? Question about the pulley puller .....as long as my mechanic has one is that sufficient or is there a special kind I need to get? Anyone suggest a site other than ClubGP<? Sorry for all the Q's but I'm having difficulty getting any info.

 

Don't go with a shift kit, these trannys are kinda weak, just leave it alone.

Get an interchangeable pulley setup(Thrasher tri-collet or Dial-Ur-Boost)

Get a puller from www.mspmotorsports.com or 3800performance.com.
The ASP one works well.

Do the hiflow downpipe, its by far the most restrictive part of the exhaust.

Go with a homemade fender well intake using a 9" K/N.

The guy at www.firebirdv6.com tunes his 3800 pcm and is known in the GP community. He is the only one I have heard of tuning his own PCM, not buying one. I would find out what he is using to do it.

 

A friend of mine has a puller. If you are interested, I will ask him if he wants to sell it.

 

thats a great car, more power would have been better than the ultra smooth idle they give that thing. My dad had one-until someone T-Boned him, I miss driving that thing, every convineince and decent power. Definetly need to get rid of the governor, That car crusies so well at 110 miles per hour, why they made it stop there I'll never know. My only suggestion is to also stay away from shift kit, since the tranny is pretty weak, my dads went at 40,000 while I was driving it--not even hard, just pulled from a light and it went out.

 

Thanks for the info. I thought a shift kit was actually good for a tranny (firmer shifts = less clutch-band wear and heat) ....no? I heard the DHP could increase line pressure in the tranny to firm up the shifts (no DHP though) also I thought these were "heavy-duty" (4t65E)?...oh well, honestly....the stock shifting isn't all that slow so not a big deal. After researching pullies I have decided on the 3.4 inch, no interchanging but thanks for the suggestion (I want to keep my DD simple-simple). Do you know if the downpipe for the Regal and GTP works or should I just go to an exhaust shop to have it fabricated? From the research I've done sounds like exhaust mods including the cat and back aren't worth it and sound lousy.....I want to keep the Riv quiet so I assume the downpipe alone won't ruin that. I guess the fenderwell intake will be common sense....looks like the intake is plenty big and free flowing, just need to eliminate the box and use PVC pipe to put a cone filter in the fenderwell. I still have the 5-inch K&N from my Powerdyne kit....maybe that will work and be plenty big for a 3800 motor? What about a manual way to increase fuel pressure just to richen the mixture up a bit for the smaller pulley? (regulator?) ....prolly just a temporary fix. Thanks for the link.

 

A shift kit is good normally, these trannys are glass, I would just leave it alone. The factory TQ rating on the 4T65E is 280ftlbs, the car makes that much TQ stock.
Just have a downpipe made, most people do that anyway.
The 5" K/N is not enough, you need a 9". The faster you can move air, the cooler it will stay.

You don't need to worry about fuel pressure or anything of the sort unless your going to a 3.0" pulley or lower. These cars are factory blown, everything is already in place to adjust for boost. The injectors are good to 400hp.
Keep in mind, SLP sells the GTX through Pontiac dealers with a full factory warranty and it has a 3.4 pulley with no other changes other than the SLP CAI.

Heat, both IAT and coolant temp make a big performance difference on these motors. Run as cool as possible. Run a low temp thermo, remove the plastic supercharger cover, and remove the weatherstripping on the firewall. Also consider wrapping the exhaust crossover pipe with header wrap, the pipe runs just below the TB.

They do make Scanmasters for these cars, they are more expensive though.

BTW-1st time at the track with just an open K/N on the TB, and a 3.4 pulley I ran 15.2@91mph, twice. I let the car cool for an hour and ran 14.6 @95mph. All runs had identical 2.2 60' times.

 

Wow, thanks for all of the great info! Speaking of the TB if it has a coolant flow thing perhaps I will bypass that like I did on the Z. Any risk to electronics via removing the weatherstripping? I heard a 7 inch K&N will fit about perfect in the Riv's fenderwell......I'll just have to figure that stuff out. From the info you're giving me I think I'm going to go with the 3.4, the homemade downpipe and FIPK, cold stat and the cooling mods you noted, and be done with it. Maybe later on a high performance tranny rebuild with 3.23's in the axle. Stealthy speed from a luxomobile is cool. Say, what's the factory HP rating on the GTX? (I guess the GTX has the same mods as the Buick GSX)

 

Just gutted the airbox. Got some info from another Riv owner that a fenderwell cone and homemade PVC style CAI with large cone filter made no gains over gutted airbox with k&N panel. It had two plastic baffles in it...one before the filter and one after it and were pretty big restrictions in place to reduce intake noise.....only about the middle 40% of the filter was getting dirty. Sounds better at WOT and the same while cruising....feels a little quicker and haven't even put a K@N in yet. The SC cover was definitely retaining some heat...it's off of there now. I'm a little nervous about removing the weatherstripping from the firewall.....have you driven yours in heavy rain like that with no problems? There are some electronics right there.

 

Cool, you should really hear the blower now. When you put the pulley on, grab a goodyear gatorback belt as well. My weatherstrip has been off for 2 years, no problems here. You can put your hand at the base of the windshield and feel the heat coming out when the car is running. You can also just do this mod at the track too.

I think the factory HP rating on the GTX was 260hp, but I'm not sure.
You can also loosen the 2 bolts on the boost bypass diaphragm(sp). Its the black canister with the hose coming out the top near the blower inlet just past the TB. Loosen these bolts, push the canister down, hold it there and tighten the bolts. This controls the boost bypass butterfly. By doing this, the valve wil close faster when you mash the gas and the car will jump into bost quicker.

 

Thanks....great info on the bypass. Is there any risk that it won't bypass at the same vacuum levels by doing this or is it only going to make it close quicker when hard-throttle time arrives? My only fear would be that it would not bypass at say 7 inches of vacuum where it did before....I wouldn't like that idea. On the flipside the benefit of better part throttle power might be fun if it closes quicker even during light throttle. Yet on another flip side could the quicker closing of the bypass cause knock retard?
Yeah, at least the weatherstipping behind the firewall just pops on and off....maybe I'll just pop it back on anytime I suspect downpours. I just learned that Intense 1.9 ratio rockers are as quiet as stock, $300, and gain about 20 HP ....sounds like a win/win as long as it doesn't kill the bottom end torque too much. I 'm also considering Flowmaster Delta 50-series mufflers with 2 1/4 inch tailpipes as a decently quiet exhaust upgrade.

 

I run a scanmaster and have seen no additional KR from the boost bypass mod.

Check out www.zzperformance.com

Very informative site and they sell parts.