Finally dynoed my turbo 3.4 dohc....430 rwhp!

[BoostGT]

sounds great, your blow off valve is hilariously obnoxious I love it what kind is it?

[FerrariFan]

Greddy.

[darkhorizon]

Pretty mean looking setup, but I wouldnt hold out much hope for it lasting any length of time... i would expect to see some headgaskets coming loose at that timing/boost level.

[FerrariFan]

Your probably right. I'll enjoy it while it lasts though
Oh yeah Dark, I like your signature too.

[Shaun41178(2)]

each engine is different. 23 degrees of timing isn't that high, the aluminum heads help with that. More detonation resistance then iron heads. I know of another dohc non fiero motor running 23 degrees of timing too but with a blower.
Matt Hawkins is making a smidge less on about the same boost, and he has had no engine problems as far as I know. Tranny problems is a diff story though.

Will come down to how it is driven. 12 lbs of boost isn't that much for a dohc motor on 93 octane.

[FerrariFan]

Matt Hawkins engine was the template I followed. I went a little bigger on the turbo though which is why it's making a little more power. you know what they say about power though...I'll try not to abuse it.

[Emc209i]

Try making 500 plus .....

[FerrariFan]

Emc209i: 500 at the wheels? I could try but that would probably grenade the transmission for sure, there's more potential the way it's setup now but 400 was my original goal and I'm satisfied with that. If you are making 500 rwhp then congratulations.
I'm not trying to be boastful, I just thought the 60degreeV6 crowd would like to share in the accomplishment. I can tend to be a smart-ass but it's all in fun. If it wasn't for all the forum posts and others far more knowledgable than me I never would have attempted to turbo the car. No doubt there are faster, more powerful cars out there but 3.4 DOHC cars with successful turbo builds are few and far between. Too many times it seems that Fiero owners don't want to spend any money on their cars because Fieros for whatever reason aren't taken seriously or seen as a worthwhile investment. There are a lot of builds out there using junkyard parts and half-ass work and the results are usually dissapointing. Those threads are entertaining and I enjoy reading about them as well, but I wanted to do something different than the 3800 SC or SBC (yawn!).

BTW, I checked out your "auto-biography" thread, nice work!

[Emc209i]

No, no .. I just personally wanna see a high number DOHC. I used to have one, so its kind of nostalgic to hear your engine idling as you backed out of the driveway in the video you posted. I'm putting together a Turbo 3800 right now, and considered trying to turbo the DOHC instead. I just wish it was a lighter motor, it makes the Fiero feel so heavy. I absolutely loved the driving characteristics of it though. Cutting out the trunk opens up a lot of room to play around with. I personally think Matt's turbo was undersized, so I was saying aim for some nice numbers.

I don't think you've ever come off as a boastful person - you seem like a pretty cool guy. And thanks for the read through of the Autobiography.

[fieromadman]

What plugs are you running? What is your target AFR? Cam timing set straight up? I have been having some detonation issues since I turned up my boost from 12 to 14 psi...

Congrats on the dyno numbers btw! And now I know I can run more timing than I am lol. My dyno charts would proove that too.

[FerrariFan]

Emc, the dohc engine with the flywheel weighs in at 465 lbs. Not much more than a the 3800 SC motor.
Madman, I'm running stock cam timing and stock NGK sparkplugs, the gap is just a bit tighter than stock specks though. I tried the Bosch platinums at first but had a problem a miss at high RPM's. The NGK's fixed that though. My target AFR at full throttle is 11. I could probably get more power with an AFR of 12 but I've got zero detonation now and don't want to take too many chances experimenting with the stock cast pistons.
good luck on the builds guys. I'd love to see your results and dyno sheets!

[fieromadman]

Thanks for the info, I'm running my after market cams straight up right now but I might need to get rid of some of that overlap. I'm targeting more of the 11.8 range and pretty much there but my plugs still read as though I'm lean. Stock plugs, gapped down considerably, I'm running more conservative timing than you but I made a new map for it to compensate. I have to get the thing on the dyno and tune tune tune. Last time I was on the dyno at 14 psi when it was blowing out spark I put down 365 to the rear wheels. I got some tuning to do... obviously lol.

[Aaron]

I'm running the stock timing maps, stock cams straight up, and stock/stock gap AC Delco Rapidfire plugs. I'm not getting any detonation, but I'm also only running 8psi (And that's at 7,000ft, figure 5psi in comparison to you guys), and have my hugely oversized A/W intercooler. I could probably get a bit more aggressive with the boost, timing, and the plugs, but I'm just too afraid.

[Matt Hawkins]

This thread has made me up the power on my car. I am running 17psi now. Hopefully I will have some dyno numbers in the next couple weeks. It feels faster.

[darkhorizon]

I'm running the stock timing maps, stock cams straight up, and stock/stock gap AC Delco Rapidfire plugs. I'm not getting any detonation, but I'm also only running 8psi (And that's at 7,000ft, figure 5psi in comparison to you guys), and have my hugely oversized A/W intercooler. I could probably get a bit more aggressive with the boost, timing, and the plugs, but I'm just too afraid.

In the real world. 8psi in high elevations is the same airflow as 8psi in low elevations. The turbo is just working a little harder the higher up you go. You can go back to fantasy land any time you want though retard.

This thread has made me up the power on my car. I am running 17psi now. Hopefully I will have some dyno numbers in the next couple weeks. It feels faster.

Let me know if you are going to do the woodward thing this week. I want to get together a turbo fiero cruise with akursed, justin, and I.

[Shaun41178(2)]

This thread has made me up the power on my car. I am running 17psi now. Hopefully I will have some dyno numbers in the next couple weeks. It feels faster.

Be carefull Matt by upping your boost. I have included a eff chart of your turbo to show that on 17 psi you are at the 60% eff line You are at the limit of your turbo hp wise. At least according to Garret because they rate that wheel to 460 hp. With you around 430 whp, you are at the limit. Granted that turbo is only a 53mm compressor wheel. If you want to make a bit more power, I would highly recommend going to a larger turbo. Or if you plan to keep it at 17 psi, I would look into a larger exhaust a/r housing for that turbo to help relieve some of the extra back pressure.

Here is your comp map for your 3071. At least thats what I thought you were running. if you changed it then I apologize.



You could jump to a 3076 which is a 57mm wheel which is good to about 525 hp according to garret, or skip that and go right to the 35r wheel, which will get you to 600 hp according to garret. I am not just saying this for the hp reasons, but also because you could make the power more efficiently. 1% efficiency can translate to an extra 10 hp at the wheels depending on how eff the rest of the system is. So even if your 3071 will make 430 whp at 60% eff, if you jumped to a 35r, and was at 70% eff, you could see an extra 100 hp at the same 17psi. In turn you could turn the boost back down to 14 psi, and blow your old hp numbers out of the water and be more eff too.

Just for reference, a gt35R wheel at 14 psi and if it was to make the same hp as your 3071, would be at 74% efficiency!!!! Not only that, but be spinning at approximately 30k less rpm. If your 3.4 motor was able to make 600 hp on 14 psi, the 35r would be at 60% efficiency. Which is the same eff as your current turbo, just with an extra 140 hp to work with with the same pressure ratio. 600 hp on 21 lbs would be at about 72% eff.

If you plan to upgrade, I would look at a billet compressor wheel turbo. Thats the plan for my new setup. Even a billet 6262 will make more power then your 3071 is now, and you can also get it in a ball bearing too.

If you are looking at a cheaper upgrade, I have two nonball bearing turbos Precision SC61's that I have been trying to sell, both with low miles, one with only about 5. They are 61mm turbos, and actually use the 35R wheel, its just not in the garret ball bearing housing.

[The Dark Side of Will]

I'm running the stock timing maps, stock cams straight up, and stock/stock gap AC Delco Rapidfire plugs. I'm not getting any detonation, but I'm also only running 8psi (And that's at 7,000ft, figure 5psi in comparison to you guys), and have my hugely oversized A/W intercooler. I could probably get a bit more aggressive with the boost, timing, and the plugs, but I'm just too afraid.

In the real world. 8psi in high elevations is the same airflow as 8psi in low elevations. The turbo is just working a little harder the higher up you go. You can go back to fantasy land any time you want though retard.

In the real world, 8 psi of boost on top of, say, 12 psi ambient pressure is 20 psi MAP, which is the same as 5 psi of boost on top of ~15 psi ambient pressure at sea level.

Now, if you're talking about 135 kPa MAP being the same airflow at sea level and at 7,000 ft, while requiring a higher pressure ratio at the compressor, then you'd be correct.

I believe Aaron's still using a boost controller that references ambient pressure, so he's right. This time.

[FerrariFan]

Matt, let us know what happens at the higher boost level. I used your setup as my template so I'm really curious just what this engine can safely handle. Keep pushing that envelope my friend!
I just added a new longer video with some improved footage, less zoom and shakiness. BTW, the engine is still going strong with no problems at 12 psi.

http://www.youtube.com/watch?v=eviMoavgR7g

[fieromadman]

Well shit, I guess it's about time I get on my A-game huh? Lol I got the turbo size to support it...

[Aaron]

I believe retard's still using a boost controller that references ambient pressure, so he's right. This time.

I am, wastegate port is wide open to the elements. Like I said, it's the same as 5psi at Matt's elevation. Makes me really think I can push it, but I'm just too much of a pussy. I'm open to 3.4 engine donations though!