8-71 blowers

If you were shopping for a roots blower and your rules limited it to 8-71's with 43% overdrive, what blower would you buy and why? We run between 8000 and 8500 engine RPM and alky.

Does DMPE make a M5 in an 8-71?

 

roots

We make an M4 8-71 however we will make an M5 8-71 special if you have the need for it. Call Jon and talk to him about your requirements 1-716-832-7583
Enjoy your day
Darren

 

My first choice would be a PSI... last year and the year before that when the Protopoutlaws rules said that big block dragsters had to run a 8-71s ,the fastest cars in the group had PSI s on them! Brandon Booher was the first topdragster and protopoutlaw in the 5s with a 8-71 on it , and I believe that Phil Esz was the quickest 1/8 mile protopoutlaw with a 3.80 @ 190mph and they both had 8-71 PSIs on them.

http://www.youtube.com/watch?v=TtS_p0MQLFc

Don't get me wrong, a lot of guys in our group with 8-71s ran fast with the SSIs and the Superman Kobelcos !

One guy in our group ran real well with a Superman Kobelco and then he made the switched to the M4, he didn't seem to go any faster with the M4 but after he made the switch he did have a lot of blower problems.

 

Speaking only on what I know, we ran very well with the PSI 8-71. We had PSI and ERD do mods to the blower the last year we ran it, the mods also included running the ERD spacer. Darren and Jon make a great product. When we purchased our PSI, there was no M4 or M5 available. We made 45+ lbs. of boost at the overdrive you're referring to. Another thing to look at is the injector, I'm starting to see the bigger the sq. inches the better. It also doesn't hurt to have the interior of the injector smoothed out and re-worked internally so it matches the inlet of the blower. If you have any questions about an 8-71 we ran them very successfully for several years and I'd be happy to answer what I can.

Brandon Booher
NHRA TAD #323
217-840-1500

 

I'a a big littlefield fan....great blowers great service and they will treat you like a human on the phone..won't run anything but mert's stuff..Dave Lowe
also I might add i've run a littlefield since high school and now iam 47

 

See that just goes to show you, they did have blowers on horse and buggies...

lol..
Sorry I had too..

 

Mike is 100% correct, at the same time there are good screw blowers and bad ones. There is no guarantee from the factory, some are just better than others. If you get a bad one and you have $$$, you order a new one and sell the one you don't want. There are a lot of guys running older blowers that just don't make the steam, along with that they may be running outdated parts and/or don't have the budget to lean on it as hard. We ran a SSI 8-71 before the PSI. When we got the PSI and it had no modifications, it was night and day better than the SSI. We had the tuneup with the SSI running faster than anyone in our class, so it'd be safe to say the tuneup was in line. The PSI and M4/5 are simply more efficient blowers. We were able to run less overdrive and make more boost, in turn it was easier on parts. If money isn't an issue I'm sure Darren can make you a billet case as well. The only drawback to the high dollar 8's is that you and a few others are the only few that run them. We had over $13k in our 8-71 and I sold it two weeks ago for $4k...but such is racing.

Brandon Booher
NHRA TAD #323

 

Which SSI version were you running?

Ours are 4 yr old F-2's and SSI modified them 2 yrs later which gained about 2-3 psi.

 

We were running an F-2 that had some mod work done on the inlet, but it was done before we got it. As far as inlets go, we saw the most gain in closing up the inlet as much as possible with the 8's.

Brandon Booher
NHRA TAD #323

 

Billet Case

Just a little FYI: PSI also has a billet roots case.

 

Are these made from extrusion ? Or are the "hogged" out of a billet ? Or are they "die forged" ? I was told by TBS, that they use extrusion?

 

Billet

It is actually carved out of a solid piece of BILLET.

 

Betcha that makes a lot of alumi chips! lol

 

ET Record

If you look at IHRA 2008 records, look for the one funny car that set the record at 5.604 with the PSI 14-71, that record still stands today.
That car then put on a M5 blower and ran well but didn't re-set any records. Per a recent email they have sold all DMPE blowers and have kept the PSI..."Yours runs quicker" Does this mean one brand is better than the other or just a customers choice for there own reasons.

 

what is the overdrive that team is using??
cheers

 

8-71

I refuse to talk bad about another mans supercharger so here is how im going to reply!
Ebrand@colinemfg.com
I ask that any or all ask Mr Brand himself any of your questions regarding the two Units Eric ran on the Coline Goalsetter Funnycar. You will find him a friendly individual and his Cylinder heads to date have made the most power on my dyno of the "fat head" design.
Or
Independent dyno test on an alcohol engine and the blower that makes the most power wins.... No talking required!

 

Norm would never say anything like that!!

 

8/71

The serviceability of a supercharger is as important as how well it performs for us here in Oz. I worked on an 8-71 PSI that was out of time from day one. There was no feasible way to retime it as they have straight cut gears , and the customer had to send it back to the states. The helical cut gear allows for timing adjustments, so to me if the blowers are identical in performance i pick the one you can work on.
Just my 2 cents
adam

 

adam

Yes a 8-71 was sent to oz by us that missed an operation in our process and it should never have happened and I totaly own that mistake and when the customer sent it back we replaced everything needed at no cost, in regards to timing why should a blower ever be able to go out of time and have to be re-timed,just because other brand older style units have that problem based on there design ? I would ask the question of anyone, have you ever had a screw or roots from us go out of time ?